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66 Toronado: Engine gutless


Guest Twilight Fenrir

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Guest 65wildcatconvt

did you say the vacumm reading on the engine was 16... that seems low to me

someone out there must remember what borderline low vacumm means,

late valve timing, late ignition timing cant remember

19 to 21 is closer to a well running engine if i remember right.:)

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Guest Twilight Fenrir
Yes, the plug does look a bit lean. The plug is correct heat range for this motor?

I dunno o.o I'm guessing so... I went to o'Reily's asked for plugs for my car... they offered me the generic ones, or ACDelco, and I went with the Delco... so they should be.

I did upgrade my ignition system though, I'm running a Pertronix II pointless ignition, and a flamethrower coil... if it matters.

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The extended crank time scenario, as described, still sounds (to me) like the QJet's bowl seals are leaking. The other issue might be the fuel pump possibly having some extra restriction it's working against, or something of that nature, to delay the new supply of fuel to the engine after the bowl is emptied. When the car has the extended crank time, and hard re-start, pull the engine's oil dipstick and see if it smells like gasoline. As the gasoline will drip directly into the intake manifold, you'll not see any external evidence of the leak. Any over-richness will be temporary, so unless you pull a spark plug during that event, everything will probably look as good as the picture.

On the '69 Chevy pickup we bought new, the metal fuel line ran upward from the fuel pump. In its route to the QJet carb, it was shielded by the massive air conditioner compressor mount bracket, even touching the cylinder head, too. I was concerned about any heat the fuel line might pickup from the engine and other things the fuel line was close to. Even in the Texas summers, it had NO driveability/restart issues . . . even with the factory 195 degree thermostat. Over the first years, I found some yellow house insulation strips and tried to wrap the line or better insulate the line from the engine items . . . no difference, but it was thin strips. Might have also been that the line had already picked up the heat and my insulation of just one part of it was ineffective as the heat was already there.

If you resealed the fuel tank, I presume that you checked to see that all of the vent lines for the tank are fully open? That the correct style of fuel tank cap is on the car?

Is the fuel pump a "single line" or a "double line" (of which the smaller line is a return line to the tank)? IF it's a double line pump. how about if you get a pair of needle nose vise grips and clamp it off when the extended crank time/hot restart scenario is operative? Over the years, there have been some of the "return line" pumps in which the orifice size "bleed" which the return line connects to is too big, allowing too much return fuel, which also means less total fuel available to go to the carb.

IF this proves to be the case, you can push a carb jet into the rubber return line section where it attaches to the pump, for a little more restriction of the return fuel flow. Look for a PM on how this situation was discovered.

Just some thoughts,

NTX5467

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Guest Twilight Fenrir

Well, my fuel system does have a return line on it. When I sealed the tank I did make sure all the vents and lines were clear. Replaced the fuel sock and everything.... I also replaced my fuel pump. When I went to remove something, I broke off the brass fitting int he original one, and had to buy a new pump. I never replaced either line between the pump and the tank though. They are probably still 46 years old. I thought about getting some lengths of braided stainless, just because I like to overdo things. I also still have the factory fuel cap.

Squeezing a rubber tube seems like a pretty easy thing to test though, so I'll give it a try in the next couple days. Do I have to worry about squeezing it too tightly?

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Guest pfloro

As NTX5467 mentioned, the primary or secondary fuel well plugs could be leaking. This was a common problem with Qjets. Without taking the carb off & examining the underside for wetness, you won't know. SOP when rebuilding these carbs is to seal the plugs with epoxy. I believe these plugs are needed to close openings which were part of the casting process for the middle (float bowl) section...

The long crank times when the engine has sat overnight and after a period of 'hot sitting' could be due to our new reformulated fuel containing ethanol. The new fuel vaporizes more quickly to reduce emissions during a cold start & warm up. Since the fuel is not under pressure in the float bowl, it could be evaporating during an overnight sit. In the morning, the bowl might be empty requiring excessive cranking to refill the float bowl before the engine will start. During a 'hot sit', the carb soaks up heat from the intake manifold. The fuel actually boils in the float bowl and percolates up the main fuel wells. It then drips out the main discharge nozzles directly onto the throttle plates & into the intake manifold. After starting, the engine will be 'overfueled' (rich running) and a few minutes will be required to clear out the excess fuel. Rough idle, black exhaust smoke & raw fuel smell will be present during this time.

I had both these problems develop during the summer of 2009. I believe that between the fall of 2008 and summer of 2009 (in Tucson, AZ), we switched from something less than E10 to full E10. I solved the cold start problems in my 1984 Toronado by switching to an electric fuel pump. In the mornings, I would leave the ignition switch in the 'on' position for 10 seconds to allow the electric fuel pump to refill the carb's float bowl. Then a quick crank would start the car (every time). I reduced the fuel percolation problem by install a 1" phenolic spacer between the intake manifold & carb. This kept some heat from reaching the carb & causing percolation. Luckily, I had enough space between the air cleaner lid and hood to raise the carb 1".

My problems were the worst during the summer months (granted, hotter in Tucson than in your area) and almost non-existent during the cooler months... I had personally rebuilt my Qjet and properly sealed the fuel well plugs before these problems began.

FYI: Fuel injected engines (throttle body or port injection) are not effected because the fuel is always under pressure right up to the injector's pintle valve. The pressure (whether the engine is running or not) keeps the fuel from evaporating or boiling...

Paul

PS: It's sad, but today's gasoline is simply not made to burn properly in carburetor equipped cars. Some engines seem to be more affected than others.

Edited by pfloro (see edit history)
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  • 3 weeks later...
Guest Twilight Fenrir

Well, now I feel really silly....er....

So, I've had an idea for the last month or so of a test I should run... but never actually did.... well, today I ran out and fiddled around, and sure enough, I think I've got my problem.

When I checked for my secondaries and switch pitch opperating, I did it by being under the hood and moving the throttle linkage. Today, I opened the hood, took the air cleaner off, and pressed down on the pedal as hard as I can... and it juuust nudges the secondaries open. My throttle cable appears to be too long.

I double checked, and there is only one place for the cable to attatch to the side of the carb, unlike the transmission rod which had 2 points. However, my carb is not original to the Toronado.... It is still a 4mV from a 66 Oldsmobile, but it's not numbers matching.... I think it would still have the same connection point though, seeing as how it is essentially the same unit?

If the connection point is the same, then my throttle cable has stretched. By about an inch it looks like. I looked underneath my pedal, and the little armature that pulls on the cable can be pushed forward, leaving about an inch of cable exposed before it presses against the firewall.

I checked oReily's and RockAuto, and I cannot find a replacement cable... Furthermore, I don't know if my cable is stretched, or just plane the wrong size.... The end of the cable by the pedal is capped off with a little crush-on ferral. Can I simply crimp on another feral higher up?

I sorted out some of the other issues as well... The winner on the hard starting issue appears to indeed have been vapor-lock, caused by an un-bled cooling system... Engine was getting too hot, and boiling off the gasoline in the lines... Having burped the cooling system, it starts pretty easily now when hot. Cold starts are also less of an issue, though there is definitely some choke-adjustment to be made to make it perfect.

I re-tested my vacuum, and I gain another inch of mercury if I cap off my accessory line... So, I've got a slight leak somewhere in the massive array of vacuum hoses that is the '66 Toronado.... So that explains the slight lean condition chalking my spark plugs. That will take some sloothing to figure out exactly where it is coming from... I might get to it next week when I've got vacation. But I know how to do it, just gotta do it.

Edited by Twilight Fenrir (see edit history)
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Good Lord. We were looking at the problem 20 some odd posts ago checking to see if the secondary opened. They sure do when your hand is working the throttle!!! LOL. Hope the cable does prove to be the issue and the Olds lights up the tires when fixed. :)

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Guest Twilight Fenrir

WHEEEEEEEE! That's fast! XD

Okay, it still won't so much as chirp its tires. And right from a dead stop the car doesn't do much until it hits about 10-15mph... then its F*ing GONE XD 0-60 in about 10.7-ish.... the GPS had a hissy fit every time I tried to run it, as soon as I got above 10 miles per hour the whole thing went blank until about 50mph when it finally caught up.

Woo man is that fun, lol.

Sorry for backtracking to the secondaries... When I first bought it it wouldn't open by hand either, so I kinda asumed it meant they would physically open XD Not thinking the cable would be an issue...

I also had to add a second spring to the throttle return... With the new shortened cable, it was sticking just a milimeter or two every time I released the throttle. Enough to rev up the engine considerably. Adding a second spring got rid of this issue handily though.

Edited by Twilight Fenrir (see edit history)
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What might be an issue is WHERE the mount for the throttle cable was between the Toro and the "other" Olds the carb came from. Over the more recent carbureted-GM years, the mounting bracket the throttle and kickdown cables snapped into had architectures to move the mounting point forward or rearward, with respect to the carb. Having a bracket that wasn't part of a matched set for the carb and cable might be where the slack came from.

IF the stranded stainless steel "cable" in the cable housing had stretched 1 inch, it's probably just got a few strands holding it together inside the housing . . . and probably ready to finally wear-through at any time. I HOPE that's not the case!

Another thing is that some GM cables had plastic sleeves on their inside ends. Kind of a pivot of sorts to protect the "dogknot" on the end of the cable, where it would interface with the throttle pedal assy. THAT could explain the additional length, if the plastic part isn't there. The plastic sleeve might also serve as a vibrationi-reducer for any vibrations which might be transferred to the accel pedal (and the driver's foot!) through the cable.

I'm glad the whole situation got narrowed down a good bit! Thanks for the update!

Enjoy!

NTX5467

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Guest Twilight Fenrir

Well.... I may have exaggerated the stretch a bit :P It was only about half an inch when I actually sat down to repair it. I dunno :P

Anywho, definitely a big step forward. Any idea why it doesn't have the go right off the bat? I'm guessing it's probably something to do with the carb, or the transmission rod... I've got a week of vacation now, so I'll do some tinkering...

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I suspect it should lay some rubber . . . BUT consider the advantage of a front wheel drive car with the drive wheels UNDER the full weight of the engine/trans combination. Usually, a front wheel drive car has about 60% of the total weight over the front wheels. A "normal" Delta 88 or 98 would have about 55/45 weight split. Not to mention the (helpful) torque reaction which (on a non-PosiTrac car) will try to raise the right hand rear wheel when significant amounts of power are transmitted to the rear axle.

IS the switch-pitch mechanism hooked up? The speed range you quoted as "less than expected" is when the torque converter would be doing its thing, whether switch pitch or not. Have you tried it hooked up and (hopefully) operational and unhooked?

What about if you add a little more base timing into the existing distributor settting? Any evidence of spark clatter? If the accel pump wasn't working, a quick throttle openning from idle would probably cause a spit-back or back-fire due to a "too lean" situation under load. Seems like I remember Oldsmobiles having a different vacuum advance source or configuration inside of the distributor than other GM division engines?

I suspect the vacuum advance is run from a "ported vacuum" source on the carb, as was normally the case back then. How about if you temporarily hook it to a full manifold vacuum source . . . then see how the part-throttle launch feels compared to what you've already experienced. Reason for "part throttle" is that if you nail the throttle off-idle, there will be no manifold vacuum to run the vacuum advance, so part-throttle is best for this test.

The reason I mention this is that back in the middle 1980s, many of the then-new Chevy C10 5.0L pickups would get "doggy" in the first 20K miles or so. Yet everything was "per specs". Our tune-up tech went to a GM traning school and came back with a "factory fix". It seems that, for some reason, they were running the vacuum advance using full manifold vacuum (which Chevy started to do back in the later '70s, on non-California emissions vehicles). When the customer would throttle into the vehicle, intake manifold vacuum would head toward "0", but with the lower engine rpm, the mechanical advance hadn't really started yet, hence "no power" (no vacuum advance and no mechanical advance meant the only timing advance the engine had was "base timing"). The factory fix was a piece of vacuum harness to go between the carb and the distributor . . . which had two vacuum delay valves in parallel, but turned backwards. This kept full manifold vacuum trapped in the line at the vacuum advance as the manifold vacuum on the other end of the harness significantly decreased. Therefore, the engine responded and was fine. In the case of a 1/2 ton pickup, it made the difference between the engine falling flat on its face or cooking the rear tire(s) when the throttle was fully openned off-idle. We sold LOTS of those harnesses . . . they usually worked, but there were a few applications where they wouldn't make that much difference.

Just some curiousities . . .

NTX5467

Edited by NTX5467 (see edit history)
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Anywho, definitely a big step forward. Any idea why it doesn't have the go right off the bat? I'm guessing it's probably something to do with the carb, or the transmission rod... I've got a week of vacation now, so I'll do some tinkering...

  • The Switch Pitch has to hooked up, working, and properly adjusted per the shop manual.
  • Make sure the carb to manifold bolts are tight and cap off your leaking accessory lines for NO vacuum leaks.
  • Look for healthy accelerator pump squirt in both primary barrels from first move of throttle.
  • If you still get hesitation after all the above are checked, try tightening up the secondary air valve spring slightly, if the valve opens too fast it can cause a bog.

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There are TWO adjustments for the secondary air valve. The one everybody knows about is the adjustment on the rh side of the carb's air valve, on the housing. The other one is that the vacuum break (i.e., choke pull-off) is what releases the linkage to let the air valve open itself, using the spring pressure to modulate when it happens. INSIDE of the nipple where the vacuum line attaches (from a manifold vacuum source), there is a restrictor hole kind of out of sight, down inside of the nipple a little ways. The size of the hole can govern how fast the air valve can open, as it'll not only restrict filling of the pull-off's vacuum chamber, but also how fast it depletes. Usually, the vacuum break issue is not a big deal, but if somebody's messed with things, it's another thing to make sure it's working as it should.

You'll need a small Allen wrench to loosen the lock-nut on the air horn housing, so you can then adjust the secondary air valve's spring tension. As I recall, with the trans in PARK, operating the throttle to open the manual secondaries with the throttle, the air valve will probably tilt open very slightly, but not much more, when correctly adjusted (per shop manual listings for "preload").

Just some thoughts,

NTX5467

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  • 4 months later...
Guest Twilight Fenrir

Well... it has been helped... but it's not really resolved yet... Work on my car has kind of been shelved the last few months, having to get alot of work done on my house before winter.

I really don't have any idea what to do with it at this point. The engine runs smoothly, and there's no other issues with it besides lack of power... Stripping it down to look at the timing hardware is alot of work, just to have a look, with no real indication that it's the problem. So, I think I'll just wind up leaving it until I have the free money to rebuild the engine.

It's up on jackstands for the winter now, so it's not going to be getting any road tests until spring.

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It's interesting that I've got the same problems with my '66 Toronado - low on power, low vacuum and a consistent stumble when idling. I too checked for all vacuum leaks and still got the same 12 inches on the vacuum gauge. Today I pulled the plugs and found just on the drivers side, #1 and #3 are rich and dry while #5 and #7 are lean. I'm wondering if this is one more indicator of a timing chain issue and if your spark plugs are showing a similar condition?

Chris

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