Electrical demons are eating my very soul!

[shuttermutt]

Well, I thought maybe the problem had somehow magically fixed itself, but it seems that's not the case. Here's a summary from an earlier post...

"...every now and again the truck will just up and die like you turned the key off. I double-checked my HEI terminal and other connections, but I don't see anything else obvious.

I'm thinking it's electrical. I can't seem to find any rhyme or reason to it. It's done it while at an idle. It's done it at ~2000 rpm cruise. It's done it shortly off the line. It's done it afer 3 miles of non-stop driving. It's done it in a straight line. It's done it after turning a corner. It's done it when the engine's relatively cold. It's done it when the engine's at temperature.

It's done it in a boat. It's done it in a moat. It's done it in a can. It's pissing me off, Sam-I-Am!

Like I said, the engine doesn't stumble or freak out. It's just like you turn the key off. When I stick it in Park and hit the key, however, it fires right back up and we're off and running."

This evening, on my way home from work, I was cruising about 65 when, BAM! The engine had died, fired back off again, and backfired something fierce. It then proceeded to freak out for a couple of miles. Die. Neutral. Start it up. Die. Neutral. Start it up.

One very wierd thing happened one time during this fiasco that kind of freaked me out... it restarted by itself. Or at least I'm 90% sure it did. It died, I popped it neutral (remember, I'm on the stupid freeway here), and when I went to hit the starter, it was already running.

Sure, you're thinking, "It might have just cut out for a moment (as it's been known to do lately) and he just thought it was dead." Normally, I'd agree, but I was eyeballing the tach before I hit the starter to specifically avoid that problem and I could have sworn that sucker was sitting at dead-cold zero rpm.

Anyway, the problem went away after about a mile and it got me the rest of the way home without so much as a hiccup. Once there, I opened the hood and jiggled every damn wire I could find on that son-of-a-gun while the engine was running and it never even flinched. I jiggled the wires going to the starter, the HEI power lead (which we'll get back to in a moment), the battery cables, all along the wires that run around the front, all the wires at the firewall, and even wires running to the A/C compressor.

Then, I crawled up under the dash and started moving those wires. I tried moving all the wires around the fuse block, any wire I could touch under the dash, and even pulled up the driver's side carpet to wiggle those around. Then I wiggled, jiggled, and tapped the key, wrestled the steering wheel, and jangled the shifter around thinking it might be in there. All to no avail.

The only thing I can see that's even slightly strange is that while the power lead going into the HEI seems to make a firm connection, the male plug in the HEI cap feels like a loose tooth. I jiggled the crap out of it, but it didn't seem to do anything. Still, the more I think about it, the more I suspect that damn distributor.

Could there be an intermittent coil issue? I thought those things were either good or bad... no in between. Could it be something like the rotor floating away from the cap or some other bizarre circumstance? All this started when I replaced the intake and carb (and, as such, pulled and re-stabbed the distributor). Normally, I'd start eyeballing the carb, but there's nothing I can think of that would make one do what this one's doing.

Thoughts anyone? This one's driving me absolutely batty!

[Tx Firefighter]

If it was me, I'd put a module, coil, and magnetic pickup in the distributor. Either one of them would do what you're describing, and for me, it's just less hassle to change them and rule them out in the diagnosis. Use genuine Delco stuff too.

[deth_1970]

id do what TX fire said, and also change the rotor and cap, the rotor might have a carbon trail causing it to ground out at times, I have seen ppl drive a truck in, and after shutting it off not start, or be driving and it dies,

[shuttermutt]

Man, by the time I replace cap, coil, module, pickup and rotor, I may as well just pick up one of those $130 Accel or Mallory distrubutors, eh?

[Tx Firefighter]

The electronic parts in those aftermarket units aren't as good as good old Delco stuff.

Flame away, hot rod guys, but I've been there and done that. OEM Delco rules for reliability.

[shuttermutt]

Originally Posted by Tx Firefighter

The electronic parts in those aftermarket units aren't as good as good old Delco stuff.

Flame away, hot rod guys, but I've been there and done that. OEM Delco rules for reliability.

I've heard it go either way. Frankly, all I've ever used are OEM Delco (because it was what was on the old part and it was still working) or no-name replacements (because that's all the parts house had). I couldn't tell you if Accel, Mallory or any of those other guys made a part that was worth a damn 'cause I've never owned 'em!

Correct me if I'm wrong, but even with just the coil, module and pickup, that's about $100 in the General's pocketbook, isn't it? I guess I just can't help but think that if I'm that close, I may as well take the $30 leap and get a new distributor from top-to-bottom.

[miket]

I had a very similar problem---with a new HEI unit----the mag pickup was shot---in a "new" as in "rebuilt" unit. Replaced it and it ran fine.

[browndawg71]

i have had a very similar problem with my truck before. it was just as you described except it started spark knocking on occasion too . i had a very simple problem the distribator was just plain wore out. its possibly you may have a pinched wire somewhere.

[69 Short Fleet]

Here is something completely different, I would replace the ignition switch, it could be cutting out on you. Possibly the PO had a gazillion keys on his keychain (heavy) and it has worn the switch itself. The loud band (backfire) could be caused by the ignition not sending voltage to your HEI and with your throttle in the same position would dump large amounts of raw fuel into your exhaust system. Then when it (ignition) cuts back in it ignites all that fuel and KA-BANG!!! It is just a thought, other than what was mentioned already, Doug

[flip66]

If you have a tach pluged in the HEI make sure it is not shorting out if any wire hooked to the tach location on the HEI grounds out it will kill the motor.

[Blackhawkdc]

ONe quick easy way to rule out the wiring to the HEI unit is to run a fresh wire from the battery, into the cab to a switch and then back out to the HEI unit. GRanted this isn't a permanent fix, but it'd completely eliminate the vehicle's wiring. If this solves the problem, you know yo've got wiring issues on the truck. If it does not solve the problem, then I'd tear into the distributor, either the pickup coil or the module could cause this. So that's where I'd go. Something really quick, simple and cheap. Who doesn't have some wire and an old toggle switch laying around?

[flip66]

Friend of mine had the same problem but it would also run really ruff some times at idel. At first we thought it was a ground because he could mess with the wire and it would start. We did not think it could be the HEI because it was only 2 mounths old. I figured out the vacuum advance was not working so we decided to swap out the hole HEI. It solved all the problems. The vacuum advace fixed the ruff idel and all I can figure is there was some type of short in the HEI.

[flip66]

one more thing make sure the gound under the top cover for the coil is not lose

[busterwivell]

Man, I feel your pain! Last summer I had an HEI that would eat a module a week. It kept getting worse. I became an expert at changing them. The HEI was from NAPA. Bought it when my 402 was rebuilt. I exchanged it with them and had the same problem. My friend got tired of this going on when with me, gave me a used HEI and the problem has not reoccurred. The old HEI is now in the core exchange pile. I always thought Modules were either good or bad, either ran on not, but Jodie (GMC Junkie) just had an intermittent problem that she traced to a module.

[Harold Shepard]

Check the coil wires inside the cap and make sure they are not pinched broken etc. also make sure you have heavy enough guage wire to the HEI. Older friend ran 16 or 18 gauge wire to his and it would act react much the same way. The original wire for Hei cars/trucks was like 10 guage or so, heavy thick stuff. May also check your fuse box connection, ign. unfused. I had Hei in old truck that the spade terminal was bad in the box and would do some funny crap, die tach would go crazy etc. Changed the wiring harness and proble stopped. Just a thought.

[67chevemall]

Ign asbestos wire is burnt up but hanging in there??
Maybe?
$0.02