HEI troubles.....

[ed2552]

My big cap HEI is not working right, i loosened the dizzy and tried to time it, and it would not run right at all. It either idled good and revved like crap or the opposite, like it was not advancing enough. There was vacuum to the vacuum advance, but i am at my wits end. If i do get another dizzy, it will be a small cap with a separate coil, because i have had it with the big cap. What do i do from here? What is the link to that dizzy guy on ebay, skip white i think?

[Pont406]

Check advance mechanism. Sounds like it frozen or rusted.

[ed2552]

Where is that? Do i have to pull off the cap, because that is going to be a PITA because the back scews are unable to get at w/o turning the dizzy to get at them.

[Pont406]

Yes, it's under the cap. You should be able to turn the rotor by hand a little and it will spring back. Very common on HEI. They get gumed out over time. If you want I can take a pic tommorow.

[ed2552]

ok, yeah a pic would be great, what do i do to fix it?

[VetteVet]

Here's a site for you.

http://www.rustpuppy.org/ignition2/Ignition%202b.htm

[WorkinLonghorn]

I had a car like that once with the back hold-down inaccessible and I just left it loose.Worked fine for me anyway.
It's not enough to have vacuum to the advance unit. You have to also have a good diaphragm.So take the hose off at the carb end and suck on it to make sure you don't get lots of air.With the cap OFF you should see movement when you apply suction.
The centrifugal advance system is also real basic,and as was mentioned by PONT406 you should be able to move the rotor a little and have it spring back. If this doesn't happen then take the rotor off (two screws I think) and spray some WD40 on the weights and pivot points and try and loosen up the weights.

[Boog]

Originally Posted by WorkinLonghorn

It's not enough to have vacuum to the advance unit. You have to also have a good diaphragm.So take the hose off at the carb end and suck on it to make sure you don't get lots of air.With the cap OFF you should see movement when you apply suction.
The centrifugal advance system is also real basic,and as was mentioned by PONT406 you should be able to move the rotor a little and have it spring back. If this doesn't happen then take the rotor off (two screws I think) and spray some WD40 on the weights and pivot points and try and loosen up the weights.

WLM is right. Just having vacumn at the advance canister is not enough. The diaphram inside it can be bad and there will be little or no advance given.
Also mentioned is the centrifugal advance can sieze up over time again limiting the amount of cent advance. Either way will make them run awful. My experience with dist centrifugal advance siezure was the weights and springs on top were fine. It was the shaft that had gummed up down inside the dist. The dist had to come out and be completely disassembled to clean it and put back together. Over time the hot oil gums up the shaft inside the main shaft causing it to stick in one spot and quit advancing the timing all together. It's nothing that can't be fixed but if you are not all that familiar with the workings of a distributor you may want to just buy a replacement "complete" dist or have someone fix yours for you. I know, it's tight quarters back there.
Why didn't Chevrolet ever move the distributors up front?

[Wrenchbender Ret]

You can check it with a timing light without pulling the cap. Check the timing at idle with the vacuum unhooked. Then accelerate the engine. The timing should advance about 15-20 degrees as the engine speed increases. Hook up the vacuum & it should advance some more. If your vacuum advance is hooked to ported vacuum (no vacuum at idle) you might try running it on manifold vacuum. (vacuum all the time except heavy throttle). I wouldn't give up on the HEI. It is good. You can do like one of the previous responses said & leave the back fastener undone.

[ed2552]

I can't find any marks on the balancer, and there is no pointer, so a timing light is out of the question.

[El Jay]

Originally Posted by ed2552

I can't find any marks on the balancer, and there is no pointer, so a timing light is out of the question.

Put a vacuum gauge on the manifold, then adjust your timing to achieve the maximum inches of vacuum.
That'll get into the ball park.

[Billla]

Originally Posted by El Jay

Put a vacuum gauge on the manifold, then adjust your timing to achieve the maximum inches of vacuum.
That'll get into the ball park.

IMHO, this makes no sense as an approach.

If the problem is static timing, then the engine should be set to approximately 10-12 degrees initial and worked from there. If that's not working, then there's another problem, and you'll need to back up and verify TDC compression #1 to make sure you have an accurate timing reference.

[El Jay]

Originally Posted by Billla

IMHO, this makes no sense as an approach.

If the problem is static timing, then the engine should be set to approximately 10-12 degrees initial and worked from there. If that's not working, then there's another problem, and you'll need to back up and verify TDC compression #1 to make sure you have an accurate timing reference.

I agree, but, he has no tab, so he doesn't know where TDC is.

[chev74]

you also have to unhook the vacuum advance and plug it with a screw or something

[ed2552]

Then people would think they were copying f**d.

[ed2552]

Where do I put it, in the line between the carb and dizzy?

[El Jay]

Originally Posted by ed2552

Where do I put it, in the line between the carb and dizzy?

No.
You need to be below the throttle body; like The PCV valve, power brake booster, or transmission modulator lines.

[Billla]

I'm not clear following this thread where the problem is. Are you saying you can't time the engine at idle? If that's the case, I can't see where the advance factors in as there should be no advance at idle, with the vacuum plugged to set static timing.

[WorkinLonghorn]

ed2552 originally posted

It either idled good and revved like crap or the opposite, like it was not advancing enough.

Did it run OK before you loosened the distrib? Some of us here are assuming not and that your problem is with the ADVANCE mechanisms and NOT with the initial timing setting. Please straighten us out.

[ed2552]

Originally Posted by WorkinLonghorn

ed2552 originally posted
Did it run OK before you loosened the distrib? Some of us here are assuming not and that your problem is with the ADVANCE mechanisms and NOT with the initial timing setting. Please straighten us out.

No, it ran like crap, and there is no pointer. Hence the post

[Billla]

This is a simple problem to solve - you MUST have a reference in order to set timing. Since yours is gone - we need to make one.

1. Buy an adjustable pointer that works for your harmonic balancer size.
2. Buy a piston stop like the one below; NAPA and others carry these

http://store.summitracing.com/partde...5&autoview=sku

3. Find TDC compression #1; if the stop doesn't come with instructions we can walk you through it.
4. Set your pointer to TDC compression #1
5. Set your timing

With this stuff, in about an hour you can be in great shape. Once the timing is right on, if there's still a problem we can look for other causes...but you can drive yourself nuts chasing this down without a solid timing reference.

[ed2552]

Ok, once it stops snowing i will get that, if it ever does

[Tynee]

Man, I remember living in SD and wishing it wouldn't snow in April. I don't miss that...

[ed2552]

March IS the snowiest month in MN, and we are supposed to get 4-8 inches today, at least they called school off

[ed2552]

Damn, today is april, isn't it.....