62 Electra 401

[jerryacheson]

I need your help on a frew fronts. I took everything off the top of my 401 and cleaned and painted it. It was running pretty well before hand but it wasn't perfect. Here's what I did:

1. I replaced the points with Pertronix. I also put a matching Flame Thrower high energy coil on it.

2. I put a new carburetor gasket on it.

3. I did not remove either the intake or exhaust manifolds. I did paint them both though.

4. I painted and reassembled the engine.

5. I had some trouble timing the car but it seems the distributor is in correctly now. I disconnected the vacuum advance (plugged) and set the timing to 10 degrees before TDC.

6. The car ran ok for a few days but it was difficult to start. (I didn't put the choke back together yet.) After it warmed up it was ok so I attributed that to the disconnected choke. (No need for a choke at 98 degrees temperature.)

7. Monday the car would start but was more difficult to keep running. When running it seemed to be running on only 7 cylinders. I'd put the car in gear and it would immediately shut down. It seemed to be electrical.

8. I noticed that a lead wire was broken on the capacitor on the regulator and there seemed to be a dead short between the battery wire on the regulator to the body. I removed the capacitor and nothing seemed to change. (I have a post elsewhere on this site asking how interchangeable these capacitors are. I should replace all 3 of them.)

9. Wednesday I decided that the car seemed to have a vacuum leak. I haven't found it. I put a vacuum guage on the vacuum line to the distributor and it measured 17" at idle. We're at about 1000 feet above sea level. The needle was pretty stable and seemed to perform correctly on acceleration. There doesn't seem to be a valve or compression issue.

10. I decided to try to adjust the carburetor. With the vacuum guage attached, I turned the fuel/air mixture valves in and out with little change in vacuum. Worst case was 15" and best case was 17". The engine kept running. (Doesn't sound right to me.) I re-connected the vacuum advance and the idle increased. It doesn't seem correct to me that I'd be getting vacuum to the advance at idle. Does that seem right to you?

I drove the car to work today to see if it just needed to be ran. It was pretty sick all day. So; what's wrong? Where do I begin to diagnose this problem? Help!

Jerry

[rocketraider]

Are you powering the Ignitor with a constant 12 vdc source or using the original resistor wire? It shouldn't make a lot of difference except in starting, but it's possible it wants full 12v.

Pertronix will usually allow you to increase base timing a couple of degrees higher than factory spec. When I installed mine, I had to play with idle speeds and timing till I finally got things where I wanted them.

If you have the vac advance connected to manifold vacuum, idle will increase with it hooked up. Not sure what Buick was doing in those years, but Chevy, Olds and Pontiac used ported vacuum for distributor advance.

Steady 17" Hg vacuum is a gracious plenty.

Just curious- is the ignition secondary wiring in good shape? Distributor cap, wires (on in correct firing order?), maybe the plugs themselves?

You're sure the choke is staying open? If not wired open, higher carb airflow on acceleration could pull the choke flap closed and cause stuff like this. Also possible carb needs cleaned and rebuilt. How about your fuel filter?

[jerryacheson]

Thanks RocketRaider,

Lots of good things to look into. Some initial feedback.

1. I used the original wire to the coil. There doesn't seem to be a ballast resistor in this car. At least there isn't one on the firewall. I'll check the voltage to the coil. I believe the Pertronix is wired red to coil positive and black to coil negative.

2. I don't see manifold vacuum. The only vacuum I can find other than the one going to power booster is at the base of the carb. I assume that's manifold vacuum too.

3. Cap, wires, rotor and plugs are all new. Firing order is correct. I didn't expand the gap on the plugs although Pertronix suggested that I could. Any ideas how wide they should be with this setup? They're currently at .035.

4. A funny thing about the choke is that there's a threaded fitting just below and toward the front below the choke spring that seems to be pulling vacuum. I just plugged it off for now. I'm surprised that this would be pulling vacuum though. What are your thoughts?

5. Air filter is new.

[rocketraider]

The vacuum port in the choke housing is to pull heated air thru the choke stove and then the coil housing. If that port gets stopped up it'll take forever for the choke coil to heat up enough to open the choke.

GM as a rule used a calibrated resistance wire from the starter solenoid to the coil (-) terminal in lieu of a ballast resistor. Serves the same purpose.

Spark plug gaps too wide will cause more performance problems than gapped too close if you don't have enough fire to jump the wide gaps. A Pertronix shouldn't have any problem here. I set mine at .045 just to have a larger flame and the Olds 350 seems to like that.

Jerry, right now I'm stumped. If I think of anything else I'll post. I'm leaning toward carb though, especially if it has a 4GC Rochester.

[jerryacheson]

It seems really strange to me that the air/fuel valves can be turned all the way in or out without any significant difference in idle. I guess that's what made me think I had a vacuum issue. I'll try some of the things you've suggested and post back. Let me know if you think of anything else. Thanks.

[NTX5467]

First order of business should be to find a vacuum port on the carb that is "ported", which it should be as there should be no vacuum to the air cleaner as later models have. BUT if the primary throttles are opened too much, you will see approximately manifold vacuum at the ported vacuum port. I suspect that if you first get the idle speed down to specs in neutral, then you will BOTH have little vacuum at that vacuum port and regain the desired and necessary sensitivity in the idle mixture adjustment. Why? Because with the carb basically working at fast idle (or the throttle is opened up enough to approximate that without the choke doing it) the carb is already pulling enough air to be working on the main system instead of the idle system. If the throttle plates are opened more than about .040" above the curb idle port in the throttle body, they they are open too much to be pulling exclusively from the idle system. If the idle speed screw is backed completely out and the idle speed is still too high, then it's either an unfound vacuum leak OR the secondary throttle plates in the base plate are cracked too far open.

On a Holley 4bbl, the secondary throttle plates have an adjustment as they also have an idle system to circulate fresh fuel into the rear bowl when the secondaries are not in use, but I don't recall that on the Carters. So, if the rear throttle plates on the Carter are cracked open at all, they flow air only and not air/fuel. Hence, a higher idle speed similar to an intake leak.

I seem to recall you have an Edlebrock version AFB on there. Is that correct?

If you do have the later style Edlbrock AFB, do the throttle bore sizes (primary and secondary) match the manifold and are not hanging up on the gasket or manifold casting itself?

I suspect that once you get the idle speed back to normal and regain the sensitivity of the idle system with the mixture screws, things will start acting correctly. One of the best ways to check for an intake leak is to pay attention to how the engine acts when you take it up to about 1500-2000rpm and let the throttle snap back to idle. If there's an intake leak, it will initialy slow down a good bit, but linger a little at the lower speed range just before it finally returns to base idle. If everything's tight with no leaks, it will not have that lingering and return to base idle in a linear manner--providing there are no dashpots to slow that last initial closing rate.

When you do get the idle speed and mixture to specs, you should be able to slow the idle speed to slower than about 400rpm in neutral just by turning the idle speed screw.

My gut suspicion, without looking at any specs, is that if you can get the slow idle to about 600-650 in neutral with the a/c running (if equipped) and maybe even the headlights on, then it should reliably drop down to about 550 in gear.

My shadetree method of setting idle speed is to get it just fast enough for the pulses in the exhaust pipe (at the back of the car) to just smooth out with it in gear and with the a/c and stuff turned on. From my experience on other cars wth non-spreadbore carbs, that works out to about 600rpm or thereabouts in neutral. From that point, set the mixture to "lean best idle" and recheck the speed and pulses. Once you get it fully finessed, it should be about as perfect as it can be for that particular engine, trans, converter combination.

I suspect that right now, if you stood behind the car with it running, the excess hydrocarbons would make you step back a few feet. Whether from lean misfire or whatever, it should not be that way.

Hope that might help . . .

NTX5467

[JohnO]

I can't help you out, but I will say I had a problem with my last 73 Electra. It would only run good if you really advanced

the timing. I replaced all the ignition parts, put in a new chain, and I still could not get it going right. Maybe the problem was

in the carb - I'll never know because I got rid of it. So, good luck - I hope you find out what it is.

[Guest brh]

Try to isolate which system you are having trouble with. I suspect its a mixture of carb and the new ignition. I installed the same system in my 65 Skylark. Car ran great. Then out of the blue it quit and was giving me fits. I had replaced the whole shooting match so why look right ? Very Wrong!!!! The reason the car quit is because the air gap on the new system was set incorrectly and was too close to the rotor. The plastic laminate was laying around my distributor just begging to stall me again. Check the new system don't get me wrong I think its great I just goofed somewhere. To set the idle on your carb. Hook up an rpm gage, turn one jet screw at a time, trying to get the highest rpms with the jets. If you turn too far your rpms should drop same thing with closing too far. One jet at a time this will make sure the carb is balanced on its fuel mix. Then use the throttle screw to adjust to specs with out looking I believe previous post is correct on idle specs. Yes you should be getting vac to the advance at all times and 17 is a great number. Worse comes to worse pull the plugs and keep track of which cyl you took it from. They will often tell you a story. Just a thought.

[rocketraider]

Hadn't thought about the air gap adjustment on the original version Ignitor. If it's off, it'll make one do weird stuff. I got the Ignitor II which uses the distributor's cam lobes to trigger the ignition. Much mo' better than setting that air gap.

[jerryacheson]

I'm using the Ignitor II as well. It bolted in with no adjustments. This car was running ok, not perfect when I first got it together and then it went away. I made no adjustments. I re-set the timing to 6 degrees BTD this evening and adjusted the idle speed to 700. I adjusted the air/fuel mixture with no real difference. The car runs better but not very good. I'll keep working through the list of things you've suggested.