coppercutlass

Guys lately i have had some ignition issues. i did see some stuff while i was in my distributor that drew some red flags. Like my secondary lead being loose on the cap and the fact there was a fair share of carbon build up on the terminals inside the cap. I tested the coil that was within spec i tested the pick up that was within spec. I did some research on a quick way to check if the module was workin and i saw a few videos but none where too clear so i made my own. I hope it helps someone down the road cheking their used , or junkyard scored hei. My module could still be bad but based on the fact im getting spark leads me to belive it might be my cap and rotor that needs to be replace. Or i need to check my wiring. Now the module does do a few things that could still be causing my issues. I still have a few more things to check once i put it back on the car. I have been out with a bummed back so today i decided since it was on the bench i could mess with that as it was light duty.

Hope this helps someone.

1BOSS83

Great video. What is the nature of your ignition issue?

coppercutlass

Been having issues upon initial start, then once it does run it runs great with no issues then if I shut it off and fire it up its fine. If I let it sit for 20 min then no more spark. I have power to the dist. Constant . The cap terminals inside had some carbon build up pretty thick too. So once my back stops bugging me I'm gonna stick the dist. Back in with an isolated power wire and check for spark again. Intermittent problems point towards the pick up but I have tested the dist 5 diffrent times with no problems . The module has connections inside that could fail when cold and work when hot and vise versa. There could be a problem with the rotor not properly putting power through the cap due to the carbon build up on the contact points. The only way to see that would be with the dist in the car with a spark tester.

1BOSS83

How are you verifying the lack of spark after the 20 minutes cool down time?

So we can 100% rule out the 12v supply wiring?

I would take my timing gun and hook it up to plug wire #1. My theory being- if their is spark traveling to plug #1 after the 20 minute cool down time, I'd see a flash.

coppercutlass

I was checking spark by taking the 1 plug wire off of the sparkplug and using a spare speak plug. Usually it's very easy to see if I don't have spark or of I do. I'm buying the spark tester because it's cheap and I'm a one man show lol. Checking with the timing gun would mean someone would have to crank it while I checked it. I spent 40 minutes at work trying to fire it up . Checked everything but pulling the dist. Out. Put the cap back on and it fired up. This makes me belive it might be a contact issue between the coil button and rotor. But since I'm carefully checking everything out before I order a new cap and rotor I need to check it in the car. Even if the module is bad I should be able to get it to fire based on the fact it's producing spark. It might not run right which oddly it did but upon initial fire up it idle rough and broke up while I held thw throttle. There is alot of odd things going on lol. But I'm slowly getting to it. My back has been bugging me so I'm just laying and trying to heal up.

olds 307 and 403

What module? Do you have the low ohm contact button on the cap?

coppercutlass

It's a proform hei and I replaced the cap and rotor and button with an msd kit 5 years ago. I have had this unit for 8 years. It's a 4 pin module.

oldcutlass

You can try and gently scrape the contacts in the cap and clean with electronic parts cleaner. You can also clean the rotor and replace the center contact if required.

coppercutlass

That's what I plan on doing eric. I still want to pin point it so be fore I clean it I wanna see if I get spark. Then if not I will clean it and proceed with other methods for checking stuff out.

71Convertible

The video is very helpful to see how to test portions of the HEI distributor, thank you! My questions are about how much testing can be done without removing the distributor from the engine. I have a 1971 Custlass Supreme with 350 cu. in. engine. The original distributor has been replace by an HEI distributor sometime in the past. I'm not getting spark from the distributor at the plugs or at the distributor post, so I don't think the plug wires are the issue. Can the ignition coils be tested without removing the distributor cap? the wires connectors are very tight and I'm concerned about damaging either the wires or the bakelite cap. Also, can the pickup coil be tested while in the distributor? I think I understand that the distributor must be removed in order to replace the pickup coil, but can it be properly tested in place with the distributor on the engine? Thanks for any additional insight.

oldcutlass

On the top of the HEI cap there are 4 screws that give you access to the coil. You can check and see if you have the negative signal to fire the coil at the tach terminal.

Connect one side of a test lamp to the battery POSITIVE cable. Probe the TACH terminal on the dist. cap while someone cranks the engine. The test lamp should blink repeatedly as the engine cranks. No blink will mean either a bad module or pickup coil. If the light blinks but there is no spark points to a bad ignition coil.

71Convertible

Thanks, it really helps to know what the different conditions indicate. Since my car was converted from a points distributor to HEI, the service manual is no help. Now to a more basic question of removing the wires from the distributor cap. The B+ lug pulled right off, but there seems to be a latch on the other three wires (black, brown, pinkish) that I have not been able to release with a small screw driver or automotive pick. There has to be a tool or trick for this that I'm missing. If so, what dimension are needed for the tool?

Professur

Dad taught me a simple method of figuring out if your spark plug leads need changing. Spray your hand with water (spitting in your palm works too) and grab one lead. Put your other hand on the fender or engine. Have someone turn the key. If you heard swearing ... they need changed.

71Convertible

I removed the ignition coil and the resistance is in spec for both the low and high resistance coils. The pickup coil also has resistance in spec. I took the module to a parts store and it tested good on 3 of 3 tests. So I haven't found a defective part yet. Is there a small magnet on the shaft that the pickup coil senses? Is the small capacitor inside the distributor something to be suspect? Other than looking for intermittent wiring issues what other parts being defective would result in no spark?

coppercutlass

I had a similar issue. New cap rotor and button fixed my issue.

71Convertible

Thanks Coppercutlass, your response led me back to what I thought was a good cap and rotor. On further examination, I found that there was some oxidation of the posts inside the distributor cap. I polished those up as well as the rotor tip and it is firing nicely now. The oxidation was the same color as the posts, so not very visible until brushed off to the inside of the black cap where it became visible. Guess I didn't look at that carefully enough the first time, but then my eyes aren't nearly as young as the car!

Thanks again!