66 Toronado: Engine gutless

[Guest Twilight Fenrir]

Hello,

I've been working on my '66 Olds Toronado the last couple years. One thing that's always been present, is a lack of power from the engine. As I understand, these cars should peal rubber all day long if you stomp on the gas, but I can't even get my tires to chirp.

I've rebuilt, and tuned the original q-jet. I'm an amateur, but it seemed straightforward with the instructions in the rebuild kit.

I rebuilt the ignition system, replacing rotor and cap, switching to a point-less ignition, new coil, plugs and wires.

I even completely rebuilt my cooling system, more becausr I had to than to resolve the issues...

When I ran a compression test, I had over 150 on every cyl. Though i'm not certain weather this is a good number or not for the stock 425.

Anything else I should look at, or can do?

Thanks

[rick60]

If the engine is properly tuned this car should pull hard. Check for restricted exhaust or problems with the transmission. Is it starting in first gear? It might possibly be a problem with the torque converter. It may not be multiplying torque. The timing chain may be loose or jumped a tooth. Did you check the distributor? Check the vacuum advance and the advance weights in the distributor. Good luck.

[NTX5467]

I think I'd make sure that when the engine is at #1 TDC that it really is there. To do this, without taking the head off, might be a little tricky, BUT might be easier to do with one of those "snake" video cameras which Harbor Frt has on sale now. I don't have one, but a friend bought one for that particular use, to look inside of cylinders without removing the head.

It could be that the harmonic balancer's outer ring (with the timing mark on it) has slipped "retarded" and if you use it to set the timing, it'll LOOK like it's to spec but will not be. Usually, the rubber between the inner and outer parts of the balancer will start working its way out from between the outer ring and the inner hub.

Also, if the timing has jumped (the timing chain), it'll similarly have lower power. If you have to advance the timing an amount equal to the distance between the spark plug wire terminals on the distributor cap, the timing chain might be an issue.

Some of the cars back then used a double-wall exhaust pipe material. With time, the inner "wall" can collapse and restrict the exhaust flow, if not stop it. Definitely a performance killer! You might take a wrench and, with the car on a secure lift, take a wrench and tap the pipe as you move front to gack on each pipe. I suspect that if you find a different sound, you'll find your problem.

You might also bump the muffler(s) with the side of your closed fist to see if there might be any rattles in there. A loose baffle can also restrict exhaust flow.

Now . . . BACK to the Qjet . . . Under the power piston is a smaller and longish spring, similar to what's in a ball point pen, but a little longer with different tension. IF that spring is NOT THERE, the primary metering rods will stay in the "ECO" or "bottom" position all of the time. When this happens, after the accel pump's "shot" is gone, so does acceleration.

In the 1980s, a friend's friend had a '80 Chevy pickup, with the 305 V-8 which had the "Half a QJet on it" two barrel carb. He'd taken it into the dealer, under warranty, for some driveability issues. After that, it never was right. He'd had it to several carb "gurus", but finally brought it to Glen one evening (I happened to be over at his house that evening). After dealing with my father's '69 Chevy pickup (350 4bbl QJet, I knew how it felt when the metering rods were in the "Eco" position all of the time). He explained to Glen how it acted and we checked a few things. I'd recently heard of the trick to check for power piston movement, which is to stick a wide blade screwdriver into the bowl vent tube (between the primary venturis at the front of the carb) to check for power piston movement. We did that, I started the truck, firmly put my left foot on the brake, put it in "D", and easily throttled into it, watching for movement of the screwdriver handle. NO movement.

Glen had already purchased a selection of power valve springs from us, so he went to his parts chest and chose a mid-range one. He quickly got the top off of the carb and gently pulled the power piston up, with the metering rods attached. There was NO spring under it. He put the spring in the hole, put the power piston/rod assy back into place, snapping the plastic cap into its lock, and then put the top of the carb back on. He stuck the screwdriver in where it had previously been. I started the engine, stomped the brake pedal, put it in gear, and eased into the throttle. As the vacuum level dropped, the screwdriver handle moved upward, when I unthrottled it, it moved downward. We put the air cleaner and stuff back on and rechecked things.

In some respects, this pickup was NOT configured for quick acceleration, with the 305 and 3.08 gears and the popular-at-the-time oversize tires on aluminum rims, but when the guy got back, then backed it out of the driveway and headed toward the corner, the truck sounded "right". The tire noise at each of the other corners he turned in the neighborhood confirmed that, as we smiled and giggled. When he got back, he was astounded and also had a big smile. ONE happy camper!

Basically, the power piston and the particular spring under it control the "fuel map" of the primaries in the QJet. At idle and higher vacuum, the vacuum will pull down harder than the spring tension will push up, so the power piston is at the bottom of its travel AND puts the largest diameter of the metering rods into the metering jet . . . "Economy". As manifold vacuum decreases, the spring pressure will be dominant and move the power piston upward and also move the smaller diameters of the metering rods upward to allow more fuel through the metering jets . . . the "main jets" in the bottom of the float bowl. When manifold vacuum gets to about 5" Hg or so at WOT, the spring will move the power piston fully upward, leaving the smallest diameter of the metering rods in the metering jets for max fuel flow through them.

The accel pump's shot will enrich the mixture as the carb comes off-idle, but it's only a temporary enrichment. On dad's truck, he didn't drive it hard enough to vary the vacuum levels enough, so with time, the power piston would stick in the "down" position. After the initial accel pump shot was used, acceleration was "on its face" . . . but if you held it WOT long enough that it got enough rpm for the secondaries to open, then it'd take off again.

So, I'd do this check to see if the power piston really moves upward with decreased manifold vacuum under load (as I did above).

The other thing happened to a service station associate. A regular customer's son put a new set of spark plug wires on his mother's '78 Chrysler (400-4bbl Lean Burn). With the timing set to specs, it clattered wildly at any acceleration, but once the rpms got to a certain level, the clatter stopped and it took off like it had a retro-rocket on the back bumper. That one turned out to be pretty easy. He'd managed to swap #5 and #7 spark plug wires, which fire consecutively on that engine and also on small block Chevies. When my friend got that straightened out, the car took off like a rocket from a dead stop.

My suspicion is that the power piston spring is gone, as few people know it's there or what it does. You'll probably have to find a carb rebuilder, at this point in time, but there is a Rochester Carburetor book by either S-A Designs or HP Books which has a full listing of all of the power piston springs ever used in QJets . . . aim for a mid-range one. Finding a dealer with an old parts book with the part number (probably discontinued) in it can be tricky. Or PM me and I'll see if I can come up with a part number for you.

If your engine acts more like the Chrysler I mentioned, then a plug wire routing double-check might be needed.

Just some thoughts,

NTX5467

[Guest Twilight Fenrir]

If the engine is properly tuned this car should pull hard. Check for restricted exhaust or problems with the transmission. Is it starting in first gear? It might possibly be a problem with the torque converter. It may not be multiplying torque. The timing chain may be loose or jumped a tooth. Did you check the distributor? Check the vacuum advance and the advance weights in the distributor. Good luck.

Well... it's got a TH425 transmission, I don't think there has ever been a problem with those ever (Obviously exaggerating) I hope not though, I really don't want to have to pull the engine to work on the transmission... I completely rebuilt the distributor, and was very careful with the timing, and the wiring.

All that stuff NTX5467 said

Wow, what a wall of text! XD But very informative, thank you very much for the time it took to type that up. I'm 99% certain I put the carb back together right. I had a fairly extensive kit, and IIRC, it came with a new power piston. I did it over a year ago now though, so my memory is fuzzy.... I'll run the screwdriver test and see what I get.

Another thing I know may be amiss with my carb, is the dashpot. It was siezed in the bore when I had taken it appart... it took several minutes with a propane torch to get it out, which, of course, melted the rubber retainer. I fabricated a new one out of a piece of square rubber, and everything seemed to work fine... however I suppose it is still a possibility.

I know, if it comes down to it, I can send my carb off to Sparky, for a complete restoration. But, I'd like to do this myself if at all possible... Can't learn without doing.

The engine runs smoothly after it warms up. It'll die right away after I turn it over, I haven't gotten the choke set just right yet. And it roars like a banshee when I flip the throttle plates by hand. Everything seems to run fine... it just doesn't /GO/.

As for the exhaust... it's very new in terms of miles on it... the previous owner put new exhaust on it during the last 30 years it spent sitting in a garage. (tabs on it were from 1982) So it's rather doubtful that is an issue. Still, a squirrel or a mouse or something could have climbed into there... or a baffle in the muffler as you said.

The bit about the harmonic balancer is something I'd never heard of... and certainly a possibility. After nearly 50 years, I'm sure the rubber is long since past its prime...

[avgwarhawk]

Is the secondary on the 4 barrel opening past half throttle? Recheck your firing pattern. I have seen two wires out of sequence and the engine ran fine....just no power. Is your distributor advancing timing? Is the kick down kicking down to a passing gear?

As for the balancer...you would know it has slipped the ring because you motor would be out of balance and shuttering. I have first hand experience when I made my balancer slip the ring using a hammer and pry bar. Went to the junkyard for a replacement. Thankfully it worked. Engine was not shuttering from out of balance.

One trick to check if your timing chain is stretched thus screwing your timing use your timing light. Hook it up as you normally do to check timing. If at every flash of the timing light the balancer/crank pulley appear to go clockwise than the next flash the balanced/crank pulley appear to go counter clockwise your chain is stretched. If your balancer/crank pulley remain consistant in direction of spinning as your light flashes then the chain is tight. This does not detect if the chain has jumped a tooth however, if the chain jumped a tooth the balanced/pulley would appear to be going clockwise and counter clockwise with every flash. Yup...first hand experience on a 455 did Buick

Edited March 24, 2012 by avgwarhawk (see edit history)

[Guest Twilight Fenrir]

Is the secondary on the 4 barrel opening past half throttle? Recheck your firing pattern. I have seen two wires out of sequence and the engine ran fine....just no power. Is your distributor advancing timing? Is the kick down kicking down to a passing gear?

As for the balancer...you would know it has slipped the ring because you motor would be out of balance and shuttering. I have first hand experience when I made my balancer slip the ring using a hammer and pry bar. Went to the junkyard for a replacement. Thankfully it worked. Engine was not shuttering from out of balance.

Yeah, I had a heck of a time with that... the switch-pitch transmission switch bar was getting int he way for the longest time with my throttle. WHen I first bought the car, the secondaries didn't open at all because of this. I was so excited when I made the discovery, hoping it would be that simple... Finding the 2nd hole int he throttle lever, and adjusting the bar. THe secondaries now open fully, and, as previously mentioned, the engine makes a deafening roar when I manually opperate the throttle. So it seems to be working pretty well in that regard.

The engine used to shudder... but I think I sorted that out when I replaced the broken rocker stud... I haven't run the engine yet this year, so I'll check that... IIRC it ran smoothly with no wobble.

Yes, when I adjust the distributor the timing does advance.

I'll double-check the ignition wires... but I'm almost certain they are correct...

[avgwarhawk]

Sounds like your secondary are opening. Distinctive sound of a freight train, small animals getting pulled into the vortex and all the air getting sucked out the garage momentarily would indicate she is doing her thing. Check your wires one more time. Assure the pattern is for this motor. Usually the fire pattern is found in the manifold casting.

[sfair]

Any engine gunning in park or neutral tells you nothing.

If the converter stator were to freewheel in both directions, the car would be slow off the line but OK at speed.

[TexRiv_63]

the switch-pitch transmission switch bar was getting int he way for the longest time with my throttle. WHen I first bought the car, the secondaries didn't open at all because of this. I was so excited when I made the discovery, hoping it would be that simple... Finding the 2nd hole int he throttle lever, and adjusting the bar. QUOTE]

Is this adjustment of the trans linkage per the shop manual? I'm no expert but I'm pretty sure if the converter is stuck in high (cruise) pitch it would adversely affect acceleration. I had a 67 Toro many years ago and the switch pitch was a great invention for such a heavy car. As far as the exhaust system restriction comments, a simple test is just holding your hand under each tailpipe outlet, you should not feel a difference in pressure. If the car has a heat riser valve it could be stuck closed which effectively shuts off one side of the exhaust system and pumps all that heat under the carburetor, good when cold but a performance killer once it warms up. Good luck!

[Guest Twilight Fenrir]

Is this adjustment of the trans linkage per the shop manual? I'm no expert but I'm pretty sure if the converter is stuck in high (cruise) pitch it would adversely affect acceleration. I had a 67 Toro many years ago and the switch pitch was a great invention for such a heavy car. As far as the exhaust system restriction comments, a simple test is just holding your hand under each tailpipe outlet, you should not feel a difference in pressure. If the car has a heat riser valve it could be stuck closed which effectively shuts off one side of the exhaust system and pumps all that heat under the carburetor, good when cold but a performance killer once it warms up. Good luck!

Heat risers.... Is that what that springed weight on the output on my exhaust manifolds is? I was wondering what those did.... So they bypass exhaust up through the intake for the heat crossover for the mechanical choke? I've flicked my driver side one curiously and it moves freely, but I never bothered to look at the oassenger side.

As for the switch-pitch, the service manual uses muddy wording... I adjusted it how it makes sense to me, just making sure that it can hit full throttle, while not holding the throttle open in idle. And that the switch gets full arc of movement.

[NTX5467]

I didn't know there were carb kits with power valves in them. Accelerator pumps, yes, but power pistons (off of which the primary metering rods dangle)? In any event, the power piston spring is NOT in any kit, but must be re-used from the original carburetor. If somebody before you might have managed to lose it, then if you put things back as they were, you might not have known it was supposed to be there, with all due respect.

The torque convertor multiplication "ratio" in a switch pitch, in "high" is about 1.9, with normal converters of that time, non-swith pitch, usually being about 2.0-2.2. That .10 decrease in torque multiplication ratio would put it in the "normal" range, so the big Olds engine should still be able to throw some gravel even if it was stuck in "high ratio". The "low ratio" was about 2.6, which would give some added motivation to get the car moving, though.

I think I'd tap on the pipes and bang on the muffler for general principles. It would be unlikely, with a "fresh" system and few miles on it in the past few decades, that a pipe might be internally collapsed (at leat on the parts which were replaced), but a spot weld holding the internal muffler baffles might have deteriorated with time, if it might have been marginal when new.

As I recall, generally, "dashpots" are to slow throttle closing for emissions purposes OR on some engines to keep the engine from dieing upon sudden throttle closing. Not a performance-affecting situation . . . at least in the applications I've seen.

As for adjusting the automatic choke, with the carb at ambient temperatures, the choke blade is supposed to just close at 70 degrees F. The choke pull-off (on the rh frt of the carb, which also governs the rate at which the secondary air valve opens) should pull the valve open a little once the engine starts. Open the throttle on a cold engine, the choke valve closes. Start the car and the choke pull-off then pulls the choke open a certain amount for reliable running on fast idle and until the choke thermostat soon starts getting heat to further open the choke. There is an index mark on the choke thermostat itself, which is indexed with the marks on the outer housing the thermostat is installed in (if it's an "integral" choke as I believe it is, rather than the thermostat being installed into a well or onto the rh top of the intake manifold beside the carb, a "divorced" choke). With age, the thermostatic coil can tighten and make and "factory spec setting" a little too "rich" (with delayed choke openning), so you once you get it adjusted to spec, you might need to back it off "in the 'lean' direction) to get things to act as they should. Generally, I like to adjust mine to be "off" as quickly as possible and still have good driveability . . . which requires some playing with things to get them to act accordingly . . . which also can mean it's a leaner and more emissions-friendly setting.

I know this might sound "different", but the only sure-fire way to inspect the timing chain is to take things apart and physically look at it. In times past, I've read of different methods of rocking the engine back and forth from a particular reference point, using a socked on the end of the crankshaft bolt to do that. But, the specs for this procedure were quite wide and could possibly vary from engine to engine. I haven't seen any specs of how to do this accurately for any of the more modern engines, though, only 1950s era engines.

In a lot of situations I saw in the '70s, many GM timing sets needed to be replaced at approx 80K miles -- some were more critical on this than others. I seem to recall many Buick 455s which were this way. My machine shop associate claimed it was because of the amount of space around the timing chain itself. Chevrolets, he mentioned specifically, has a timing cover which was close to the chain, so when the chain started flopping around on the non-tension side, it would rub the metal cover and eventually result in an oil leak from the side of the front cover. Voila, remove the cover and find the worn timing set. Replace both the set and the cover and everything's good to go again. Other GM engines, by comparison, didn't have timing covers which would serve as a "timing chain guide", though. Of course, when one of the plastic teeth on the cam sproket breaks, then the chain "jumps" one notch and things start acting poorly . . . while driving or otherwise--significantly so. If you then pull the oil drain plug out for an oil change, little pieces of plastic gear can be seen in the used oil.

I'm not sure how many miles are on your engine, so this might be a judgment call of sorts. But I'd first check everything externally first.

As for the harmonic balancer, other than the rubber sandwiched between the outer ring and the hub pooching out, the outer ring can also move forward on the rubber . . . which is not good either, especially for the radiator if it keeps on going.

IF you do pull the balancer off (with approved special tools for such), please roll the engine to the "marked" TDC position. In many engines, at that point, the keyway on the nose of the crankshaft should be parallell with the #1 connecting rod, pointing to the center of #1 piston. This is a generallity which I've noticed on other engines, but I'm not sure if the Olds engines are that way. Once in a great while, the keyway can be machined in the incorrect position from the factory, which can result in a generally "doggy" engine when set to specs, but "normal" once the base timing is advance "by ear" for best running. By observation, "to factory specs" is a good starting point in tuning an engine, but it might not be the best place to end up if a little more performance is desired, especially in the area of ignition timing.

Keep us posted, please.

Respectfully,

NTX5467

[avgwarhawk]

My 73 455 timing chain was very stretched. The engine had 110k or there abouts. If I remember correctly I had to turn the cam about one inch to get the gears aligned for the new chain/gear assembly.

When working on cars back in the 80's I experienced more often than not if a chain can jump a tooth it was due to the plastic coated teeth breaking. Most times if not all the chain jump would completely shread the plastic coated gears and car would arrive to the shop on the hook.

The rubber belts much the same story when it jumps a tooth.

[Guest Twilight Fenrir]

Okay, well, I have tomorrow off, and after I finish the last couple steps in my disc brake conversion, I'll get into investigating this again....

For fuzzy memories sake, I looked up what the power piston looks like, and found a picture with it, and the spring beneath it... I don't remember that spring being there. It's been awhile since I did it, so that is far from conclusive... It would be wonderful if it was that easy.

I'll start with that test, as it sounds far and away the easiest thing to check, along with the plug wires.

I'm really hoping it's not the transmission, or the timing chain. I'd prefer not to take things that far apart just yet. Did they even have nylon gears in 1966? I thought that was more recent... aren't my timing parts metal?

As for the miles on the car... The odometer reads 65K-ish... Originally, I thought this meant it was 165K. And, one of the title-transfer copies I found in the dash lists that the previous owner thought the same thing... But so much of the car is in such good shape, and I know for a fact, the car sat in the garage I bought it out of for 30 years... I think that may be original mileage. Cars don't generally survive to 165K miles of Minnesota without major rust.

[Guest Twilight Fenrir]

In the 1980s, a friend's friend had a '80 Chevy pickup, with the 305 V-8 which had the "Half a QJet on it" two barrel carb. He'd taken it into the dealer, under warranty, for some driveability issues. After that, it never was right. He'd had it to several carb "gurus", but finally brought it to Glen one evening (I happened to be over at his house that evening). After dealing with my father's '69 Chevy pickup (350 4bbl QJet, I knew how it felt when the metering rods were in the "Eco" position all of the time). He explained to Glen how it acted and we checked a few things. I'd recently heard of the trick to check for power piston movement, which is to stick a wide blade screwdriver into the bowl vent tube (between the primary venturis at the front of the carb) to check for power piston movement. We did that, I started the truck, firmly put my left foot on the brake, put it in "D", and easily throttled into it, watching for movement of the screwdriver handle. NO movement.

Just some thoughts,

NTX5467

Okay, just for certainties sake, we are talking about doing this, correct?

If so, I stepped on the brakes and held them, put the car in drive, and slowly revved the engine up. The car wiggled as the engine struggled against the brakes, but the engine kept going higher, until it actually stalled. (whoops) But, durring the entire time, the screwdriver did not move a millimeter.

So, if I did this correctly, I am almost certainly missing that spring beneath the power valve, and all I need to do is buy an appropriate spring, pull off the top portion of the carb, put it in, and re-assemble (With new gaskets) and that'll be that? (Minus the potential for other problems being present)

[NTX5467]

As I recall, the power piston is pretty much right under the bowl vent, so it should be easy to hit with the screwdriver . . . as pictured.

From the way it acted, the reason it died was due to a lean mixture for the load on the engine. If things had been acting correctly, the engine would have labored as the rpm reached it's possible-under-load level, but not died. Or possibly started missing on a cylinder or two if the plugs or wires were having a problem under that higher load.

As I mentioned, there were about a dozen different power valve springs in the chart, but remember, too, that the QJets were used on engines from the Pontiac 230 cid OHC 6 cylinder to the 455 GS Buicks and similar Oldsmobiles and Pontiacs . . . even the 500 cid Cadillac V-8. Each spring had their their respective dyno-proven reason for being and correctly phasing the transitions between Idle/Economy, Mid-range cruise, and Full Power conditions. But at this point in time, just having something under there is the most important thing.

The last model year of use would have been in the middle 1980s before we got the electronic solenoid and jet package which replaced the vacuum-modulated power piston and metering jets as you have. Perhaps there's what I'd term an "old line, embedded, carburetor shop in your locale that might have some springs in a dusty drawer on the top of a workbench somewhere? Or you might find a core carb at a swap meet? Or perhaps you might contact "Carbking" Jon at admin@thecarburetorshop.com "Carbking" is his screen name in the AACA forums.

Take care,

NTX5467

[Guest Twilight Fenrir]

Well, thus far with a general internet search, the only thing I've turned up is this set of 4 springs here on the cleverly named, quadrajetparts.com

Power Piston Spring Assortment - Rochester Quadrajet Carburetor Parts

Also, these ones from Edelbrock:

http://www.jegs.com/i/Edelbrock/350/1994/10002/-1

I'd hate to have to put one in, put it together, test, rinse, and repeat though... I'm going to check with Sparky and see if I can get one from him, if not, I'll check with Carbking. Thanks alot for the help. If it's really this easy to get my car burning rubber, I will be thrilled to no end.

Edited March 27, 2012 by Twilight Fenrir (see edit history)

[Sweepspear]

Okay, just for certainties sake, we are talking about doing this, correct?

Just my 2 cents, but that looks like a rather heavy screwdriver to use for that test.

Besides, with the engine shut off you should be able to put a screwdriver or what have you down that hole and tell if the power piston has a spring under it or not.

[Guest Twilight Fenrir]

Just my 2 cents, but that looks like a rather heavy screwdriver to use for that test.

Besides, with the engine shut off you should be able to put a screwdriver or what have you down that hole and tell if the power piston has a spring under it or not.

Hmm... interesting point about the weight of the screwdriver... it's lighter than it looks though, the tube is very small on my toro That's actually a fine electricians screwdriver. Even though it's closer than the air-cleaner screw, it's smaller across than that is. That's... what, 1/4"?

That being said, I did try pushing down carefully while the car was off to see if it sprung. It did not, but I wasn't sure weather that was a valid test or not.

EDIT: Okay, just to be sure, I ran out there and took a flashlight and looked down the tube. I ran the test wrong. The piston is only in the very front most fraction of the tube. I kinda just pitched it in there when I ran the test

Using my electricians screwdriver, I tried to push down on the correct part this time, and I still got no movement at all.

Edited March 27, 2012 by Twilight Fenrir (see edit history)

[Sweepspear]

Hmm... interesting point about the weight of the screwdriver... it's lighter than it looks though, the tube is very small on my toro That's actually a fine electricians screwdriver. Even though it's closer than the air-cleaner screw, it's smaller across than that is. That's... what, 1/4"?

That being said, I did try pushing down carefully while the car was off to see if it sprung. It did not, but I wasn't sure weather that was a valid test or not.

EDIT: Okay, just to be sure, I ran out there and took a flashlight and looked down the tube. I ran the test wrong. The piston is only in the very front most fraction of the tube. I kinda just pitched it in there when I ran the test

Using my electricians screwdriver, I tried to push down on the correct part this time, and I still got no movement at all.

Sure sounds like that spring may be missing.

For what it's worth, the company Quadrajet Parts.com that you linked is a good outfit to do business with.

I've ordered kits and other parts from them in the past.

Edit: I just now noticed you are also from Minnesota.

[Guest Twilight Fenrir]

Sure sounds like that spring may be missing.

For what it's worth, the company Quadrajet Parts.com that you linked is a good outfit to do business with.

I've ordered kits and other parts from them in the past.

Edit: I just now noticed you are also from Minnesota.

Alrighty, I just went ahead and ordered the spring set. It's not too big of a deal to take the top off a couple of times to find the right one... One out of the 4 has got to be close enough....

I went to Eddelbrocks site, and they have greater specifics, they tell exactly what pressure the springs collapse under. I also bought a vacuum gauge (needed it for setting my idle right anyway) So, before I take the carb appart, can I just hook up the vacuum gauge and re-perform the hold-the-brakes test and see what the vacuum drops to, then use the appropriate spring?

While I've got the carb off, I'll be replacing my fuel bowl plugs, which are leaking again... This time I'm going to tap the holes and epoxy some stubs of threaded rod into there, sealing it up for good.

When I've got that straightened out, I'll be able to set the idle, and the choke.

Also, yup, I'm up near Virginia, about 100 miles NW of Duluth. Not often I go to the cities, can't stand down there XD Though, having 4-5 lanes of traffic is always exhilerating. Up here, there's barely ever 2

[NTX5467]

In Holley power valves, the value at which the power valve starts to open should be a few inches of Hg less than the "in gear" idle vacuum. In my '77 Camaro 305 with a Cam Dynamics 266 cam (210 @.050", .440 lift) it would go down to 10.5" Hg, which is on the ragged line as the two-stage power valve opens at 10" Hg and is full-in at about 6.0" Hg. Most of the normal Holley single-stage valves were about 8" Hg. I suspect that something in that range would work for you.

Just some thoughts . . .

NTX5467

[Guest Twilight Fenrir]

Okay! Set about taking appart my carb again.... and, surprise! the spring is still in there... the problem was, the little wire holding the primary metering rods onto the piston was pressing against the bottom of the top portion of the carb, and keeping it pressed down. After fidgeting with it for a couple minutes, I managed to get it back together, and it now moves freely!

The engine definitely seems to respond a bit better, I can accelerate more quickly... but I still can't get my tires to chirp at all O.o So, either I've got insanely good traction on my Firehawk Indy 500's, or there's still a problem somewhere....

[NTX5467]

Thanks for the update! I'm glad the power piston is now operating as designed.

Have you, just for general principles, checked the rpm at which the engine "stalls" against the fully-applied foot brake in "D"? Perhaps there has become an issue with the torque converter not converting torque as it should, at lower speeds? How does it act from 30mph and higher with WOT application? Part-throttle, light and heavy?

Just some (more) thoughts . . .

NTX5467

[60FlatTop]

Have you parked the car on a level surface and put it in neutral to see if you can make it roll by pushing lightly? The brakes could be dragging.

Bernie

[carbking]

I didn't know there were carb kits with power valves in them. Accelerator pumps, yes, but power pistons (off of which the primary metering rods dangle)? In any event, the power piston spring is NOT in any kit, but must be re-used from the original carburetor. If somebody before you might have managed to lose it, then if you put things back as they were, you might not have known it was supposed to be there, with all due respect.

Respectfully,

NTX5467

Willis - our Rochester 2G and 4G kits HAVE power valves; and our Q-Jet kits DO HAVE the correct power piston springs. And no, the power piston is not in the Q-Jet kit.

In the FWIW category, there are a couple of Q-Jets (Olds in the early 1970's which do NOT use the power piston spring).

Jon.

[NTX5467]

Thanks for the information, Jon! Now I know where to get those kits, if needed!

What about the secondary air valve spring for ThermoQuads? Although I've got the tool for the adjustment, seems like every spring has broken the adjustment tang "at the bend".

Thanks,

NTX5467

[carbking]

Thanks for the information, Jon! Now I know where to get those kits, if needed!

What about the secondary air valve spring for ThermoQuads? Although I've got the tool for the adjustment, seems like every spring has broken the adjustment tang "at the bend".

Thanks,

NTX5467

Willis - the secondary airvalve spring for the TQ are in the rebuilding kits as are the quad X-rings (not O-rings like are found in the FLAPS kits).

Jon.

[Guest Twilight Fenrir]

Have you parked the car on a level surface and put it in neutral to see if you can make it roll by pushing lightly? The brakes could be dragging.

Bernie

Brakes are good. Just finished rebuilding them all, and the car rolls remarkably easily for as big as it is.

Alright! I went out and did some more testing today...

For giggles, I took it out on the road with an app for my phone that allows me to use GPS for a speedometer, and also will keep track of 0-60 and 1/4mile speeds. My 0-60 took 13.2 seconds... Factory spec is 7.5 seconds. So, a problem there certainly is.

I tried the holding in the brake and stepping on the gas technique with my dwell tach hooked up, and the engine actually did not die. The RPM's got up to about 1,400 and wiggled down to 1,300 before becoming stable there. It only died when I let off the gas. Which, could very well just be my jurry-rigged dashpot.

While I was at it, I also set my idle. I get about 16" of mercury at idle now, that was as high as I could make it go by adjusting the idle screws with the car warm.

I also septouple-checked my ignition wires. They are definitely in the correct order, however, I wonder if they might be rotated too far? I understand this is used to set idle, but I'm not 100% sure on how all of these things work together, I just know what they do on a broad sweep. Anywho, here's is a picture I took of the car, the front of the engine is exactly straight with the left side of the image:

Now, here is a diagram from my service manual:

As you can see... While the order is correct, the (1) on my car appears to be where the (2) is in the chart. Does this matter?

Thanks again.

[Bruce_C]

By the way, here is a great book on rebuilding Qjets - How to Rebuild and Modify Rochester Quadrajet Carburetors

by Cliff Ruggles

He also rebuilds them, but the wait time is very long (10 months ?)

Bruce

[Guest Twilight Fenrir]

By the way, here is a great book on rebuilding Qjets - How to Rebuild and Modify Rochester Quadrajet Carburetors

by Cliff Ruggles

He also rebuilds them, but the wait time is very long (10 months ?)

Bruce

Yup, I own that book already

[joe_padavano]

Does this matter?

No. So long as the timing is set correctly, where the wires are located on the cap is irrelevant. It's likely that the distributor has been out of the car at one time and was not reinstalled in exactly the factory location. So long as the rotor points to the no. 1 plug wire when the no. 1 cylinder is at TDC on the compression stroke, the actual clocking of the wires does not matter.

[avgwarhawk]

The wires can be walked counter clockwise to match your manual picture. In other words, move 1 to 8. 8 to 4. And so on. It is possible the distributor was reinstalled a few teeth off but still runs OK.

[Guest 47jag]

Twilight,

I'm going back 50 years but I had a problem that I only ever seen once on an Olds 98 like you describe and it was a little cam (about 3/32" thick) that sits in a slot between the secondary air valves attached to the valve shaft. As the secondaries open this cam lifts the metering rods out of their lets allowing more fuel. You can check it without running the engine. Open the air valve and see if the rods lift.

Art

[NTX5467]

The secondary air valve metering rod cam is one which not many people are aware of. In fact, it's somewhat hidden in the older GM parts paper catalogs! Some years have a part number for it, some years don't admit to it.

I don't know that there were "factory specs" for acceleration and related items from USA manufacturers back then . . . or even now. The European manufacturers would share their numbers, but what we saw on this side of the water was what the car magazines got and printed in the various road tests. In the generation of their acceleration numbers, they might use some driving techniques which most "from the red light racers" might not use . . . as staging the car against the brake before the tree's lights come into motion. Those earlier tests were run with a co-pilot doing the data recording with stop watches and an attached "5th wheel" for accurate speed readings. In reality, a better gauge would be the 1/4 mile trap speeds rather than 0-60mph runs. The observed "stall speed" seems a little low, but not terribly so . . . I would have thought that something like 1600rpm might be more appropriate.

On the Wild About Cars - Your Ultimate Automotive Resource website, in their archived road test section, they did a comparison test between a '66 Toronado and a '66 Riviera GS 425 2x4bbl car. For the Toro, they achieved 0-60 in 9.0 seconds and the 1/4 mile in 17.9 seconds at 85mph. As I recall, this was "ballpark" for that weight of car. The slightly lighter Riv did 8.3 seconds to 60 and 16.8 seconds and 86mph in the 1/4 mile. The Riv was about 300 pounds lighter and had a 3.42 axle with 8.45x15 tires . . . the Toro had a 3.21 with 8.85x15 tires and the single QuadraJet carb. Both of these were in the same article from CARS magazine of late 1966.

Just some thoughts,

NTX5467

[Guest Twilight Fenrir]

I don't know that there were "factory specs" for acceleration and related items from USA manufacturers back then . . . or even now.

Just some thoughts,

NTX5467

I was just going with what Wikipedia said on that one

So... I might have a little more data to input onto this...

I've always had trouble getting my car to start when I went out first thing in the morning... gotta basically pump the gas pedal repeatedly until it starts. I always just wrote it off as choke not being adjusted right.

I don't generally do alot of driving where I stop in to a place for a bit, drive somewhere else and do the same.... yesterday, I had such a day, where I made many small trips, and had some problems I had noticed to a lesser degree become much more obvious.

If I turn off the ignition, and come back within a few minutes, it will start right up fine. If I turn off the ignition, and leave it sit for about an hour or so... it becomes really, really difficult to start. I have to hold in the gas pedal and crank and crank, it will usually fire and sputter a few times before dying, and I must repeat the process several more times while I fiddle with the pedal until it is just right. If I try to take off right away, it will die. I have to sit, holding in the gas just enough to keep the rpms above idle for a minute or so, then I can drive and come to a stop without any issue.

I've been driving with my windows down a bit more lately, and I think I smell gasoline when I'm driving too... I've had it idling in my garage, and I don't see any fuel leaking anywhere.... I know everything from my fuel pump up is good, I replaced it all. And there are no visible leaks on my carburetor. I also recently re-sealed my tank... The lines from the tank to my fuel pump are probably original though, I'll replace them over the next few days just to be safe.

Are any of these symptoms pointing at anything?

Thanks.

[avgwarhawk]

Hard start when hot. Vapor lock. The gas smell, is she running rich?

[Guest Twilight Fenrir]

Hard start when hot. Vapor lock. The gas smell, is she running rich?

Vapor lock is when the gasoline boils inside of the line right? I don't think that's the case.... my fuel line doesn't run anywhere near anything particularly hot, exempting the engine block itself.

I don't think it's running rich. But, then, I'm not really sure how to check for that either...

[avgwarhawk]

Near the block with the metal fuel line is sometimes enough for vapor lock. The hot start issue this would be my first thought. Running rich can be seen at the tailpipe emitting black smoke. The plugs will be black and fowled. Gas mileage is horrible. Smell of gas. To be sure, these older cars did not have much of a system to retain gas vapors from escaping. You will get some gas smell from time to time.

[Guest Twilight Fenrir]

Near the block with the metal fuel line is sometimes enough for vapor lock. The hot start issue this would be my first thought. Running rich can be seen at the tailpipe emitting black smoke. The plugs will be black and fowled. Gas mileage is horrible. Smell of gas.

Well, I actually replaced my metal line with a length of braided stainless tubing... So it should be better insulated than the regular hard steel... i imagine....

My tailpipe doesn't emit any kind of smoke at all unless it's a bit cooler out, then I'll get a light white. I know previously I burned through one batch of plugs that turned a chalky white from a lean mixture... but that was before I had rebuilt my carb. I have not pulled my plugs since. I'll pop one or two out and take a look.

My gas mileage appears to be fairly typical... Running about 12-13mpg mixed driving conditions.

[Guest Twilight Fenrir]

Well, plugs look just about right, so I'm probably not running rich... That eliminates another question I had, as I re-sealed my fuel bowl plugs when I did my carb, and was worried they might be leaking again. But if I'm not running rich, that's probably not a problem.