Problems after HEI install - UPDATED DIAGNOSTIC INFO

[Fab64]

Hi all,

I did the HEI conversion on Saturday, Feb 4th. I thought I had succeeded in getting everything running okay at that time, but am having problems now. To re-cap, here's what I've got:

Re-mfg 303690 (for a '74) distributor from RockAuto
VC208 vacuum can (11R)
AC Delco D1906 control module
Standard FD-478X coil
Standard CH-410X cap
Echlin MO-3000 rotor
NGK ZFR5N spark plugs

All of this is installed on my 225, with a Holley 2280 2-bbl.

That first time I drove with it, it ran great, and was idling very smoothly. I drove it to a Subway's about a mile away, then back home. On the way home, I noticed a slight miss at idle. After reading other accounts on here about failures soon after installation, I figured I would stick close to home for a while. I didn't drive it at all that week until last Friday night (Feb 10th), when I took it to a store about 2 miles away, then to a restaurant to pick up dinner on the way home. I knew I was taking a bit of a chance, doing this at night, but hoped it would be okay. I got to the store fine, but while driving thru the parking lot to leave, it sounded like it was starting to miss and stumble a bit. I drove around the parking lot for a while, and even opened the hood to check how hot the module was - it didn't feel warm at all. I got back out onto the main street (one of the busiest around, and clogged with traffic at 6:00 pm on a Friday night), and nursed it up to the restaurant, picked up my food and got home as quickly as I could. I didn't mess with it until last night. I tried starting it just to see how it was running. After managing to flood it, I finally got it started, and it didn't seem to run too badly. I went out this morning to double-check all my wiring and my grounds, and now I can't even get it started. I've double-checked all my wiring, and everything is hooked up correctly, as follows:



I have verified that the distributor wires are correctly hooked to the module, per Charrlie_S’s instructions: “The male pin on the distributor connector, goes to the "W" terminal of the module”.

Both of the control module screws are grounded, and I used the heat sink compound underneath the module. Btw, does this compound conduct electricity at all, or is it just for heat dissipation?

Is there any way to check what's going on here? Is it possible I've burned out the module? If so, how??? I have a volt/ohm-meter, but am not an electrician by any stretch, so not sure what to check. I'd appreciate any suggestions – thanks.

Roger

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[SlantSixDan]

It sounds like you did a careful installation. Heat sink grease is only for thermal connectivity, not electrical conduction. Have you checked to see if you have spark? If you do not, I think my first suspect would be that "remanufactured" distributor. If it is bad, get the new one you should've bought in the first place.

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一期一会

By birth & parentage: US citizen, 2nd class
By choice: Canadian citizen, 1st class

[Fab64]

[SlantSixDan]

[neilskiw]

The poor running/missing you described reminds me of my own HEI install. The problem turned out to be the HEI module (used- thereby confirming Dan's bias on used or reman parts).

After purchasing and installing a new module, I was pleased with the improved idle characteristics, and improved fuel economy. I also put a second module under the hood, just in case.

Scroll down to the picture of the install (now owned by Nongan).

http://www.slantsix.org/forum/viewtopic.php?p=341609&highlight=#341609

The improvement is well worth the pain!

[Mroldfart2u]

I agree, pull module and run it to AutoZone for a test... its free and quick... That has happened one time to me on my lean burn delete on my c body'ed 440.. ran great for a few days and just quit. I had the receipt in hand and AZ exchanged it @ no charge...

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MRO....

Cheap, Fast, Reliable.... Pick 2...

[Fab64]

Thanks, guys. I'll take my module over to Autozone and have it tested.

Btw, this was a brand new, official Delco/GM control module. If my problem is, indeed, caused by a bad module, any ideas what might make it go out? After all, it was running fine at first. Could a bad ground have caused the module to burn out? I ask because I initially ran my ground wire to the module screw on the side the distributor wires connect to. I then read in Olaf's post that the module should be grounded on the opposite side screw. I had not read this before. As always, thanks for any input.

Roger

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[Fab64]

Finally got some time to look into this a bit more. Took my control module to AutoZone and it tested out fine. That eliminated one component.

Wired the new coil (Standard FD-478X) into my old ignition setup, and it won't start. Using an Ohm-meter, I measured resistance of both old (Pertronix Flame Thrower) and new coils, between Pos and Neg terminals (side-to-side), and from one side terminal to the middle high-tension terminal. According to articles I've read, the side-to-side reading should be between .7 and 1.7 ohms, and the side-to-middle should be between 7,500 and 10,500 ohms. Here's what I found:

Old coil: side-to-side=1.6, side-to-middle=9,900
New coil: side-to-side=.7, side-to-middle=5,900

From these numbers, I assumed the coil was bad. I then re-installed the HEI control module and the electronic distributor, but wired it up to my old coil. It started right up. Which means the high-falutin', fancy, premium Standard BlueStreak FD-478X coil that I bought - brand new - was bad.

Unfortunately, I now have a new problem: the runs-with-the-ignition-key-off issue has returned. A while back, someone else reported this in another post, but I don't remember what the solution was, and I can't find the post now. I suspect this has something to do with the power relay that I am using. My next step is to take it out of the equation and see if it solves the problem.

As an aside, I don't think the Chrysler engineers could have made it more difficult to remove and re-install the distributor in these cars if they had tried! But I digress.

I would appreciate any advice for the run-on problem I'm having. Thanks.

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[Supercharged SL6]

Running with the key off,I had that problem when I installed a delco alternator and used the power wire from the OE regulator to power up the regulator in the delco alternator, the wire you have going to the relay may be hooked into the alternator regulator circuit, I had to run a wire from the keyed side of fuse box to the regulator in alternator to keep it away from the ignition other wise when I turned the key off with the alternator still spinning it would put power to the ignition,I believe the power wire for the ignition & regulator are the same when everything is all chrysler it works OK but when you add a GM component the power is back feeding from the alternator to the ignition

[Fab64]

Thanks for the info. Yes, I am using the OE regulator wire to power my trigger feed (terminal #86 on the relay). I checked it beforehand, and it was only live when the key was on. But I've been speculating that that might be what's causing my problem. It hadn't occurred to me that power coming from the alternator might make that wire live even with the key off (duh!). It rained all day today so I haven't had a chance to get back to it, but I'll move it to a different power source and see what happens. I appreciate the feedback.

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[raycycled]

I have successfully put an Oz Hemi 6, after market electronic dissy in our 63" Valiant, done over 2000 miles now never misses a beat, the clearance on the inner gaurd is minimal but the 63 valiant is a small car with the later models you should have heaps of room and only cost me $130, RAY