HEI Blues

I am at my wits end and am looking for any advice on the following problem. If you could give it a think and tell me what you believe is up I would greatly appreciate it.

I have a 1965 Chevy pick up with a 396, I went to start it on Thursday and nothing. I had zero spark at the spark plugs. I assumed I had a bad coil and promptly replaced it with a new moroso coil, still no spark. I removed the entire HEI distributor from the truck and took it into a local shop, had it bench tested it and it worked. I took it back to my truck installed it and no spark. I bought and installed a new ignition switch and re wired all the wires to and from my ignition switch. I have 12 volts at the coil I have 12 volts going from the coil to the distributor base via the pigtail but still no spark. Took it back to the shop put it on the bench and it works.
I have a good ground from the engine block to the engine frame. I jumped the distributor directly from the battery to the coil as well as the ground and unplugged the power pigtail to remove any faults that may be lurking in my wiring, no spark. Now here is where it gets interesting. I took the distributor out of the car and connect power off my battery and ground from the same mounting plate that holds the distributor in, spin the cam gear in my hand and it has sparks. Put it back in the truck no spark. I know what you are thinking, broke or damaged timing chain or gear. I have verified that I have rotation several times over the past 4 days.

Any help will certainly gain you entrance into car heaven.

Terry (ter-nan)

Toys only count if they work. Yes I have varified that the "rotor" "rotates" when the engine is cranking over. Faulty spark plug wire? All eight, at the same time. I am reaching for answers but I do have my limits.

Terry

I think it's a bad ground or bad electrical connection somewhere.

I had painted the intake manifold and the hold-down during an overhaul. When I reassembled everything, I had no spark. Then it would start for a second, then no spark. The ground was made by the camshaft gear, intermittently.

I cleaned and sanded the hold-down and the "ring" on the manifold so the distributor could ground. No problems.

If I had a bad ground or wireing then it wouldnt work when I held it in my hand using the same power and ground as in the truck. I'm missing something but I don't know what. I sanded the hold down clamp and the point where it makes contact with my distributor.

If you are holding it in your hand, it can't POSSIBLY have the same ground as it has when it's in the engine. It's grounded THROUGH the housing to the engine. If it's out of the hole, then it's not grounded as installed.

Its clear to me that he is grounding the distributer body remotely......ter-nan......I would take a close look at the pick-up assembly...the OEM wires that come out of it become brittle with age and break with only the insulation hanging in there..I don't trust the pick-up...They all get new ones when I am into the older distributers....The pick-up is not hard to change...The drive gear has to come off and thats a good time to inspect the drive pin...and clean eveything up......Its pretty clear something is changing after you install the distributer...The pick-up has to have the correct air gap to the actuator...The end play of the distributer shaft could be changing this after its bolted down in the intake hole...How about the module assembly..(the little black box)...It can not be loose and it must have a clean ground...Confused about the pick-up assembly.??...Check out a new one and the good ones have pretty good instructions on how to change and set them up..............All our toys are important to each of us no matter how much we have invested.....My 65 Chevy trucks are not perfect ..not worth a whole lot....but they are mine...

Are you testing between the + wire for the distributor and the engine block? If you are, then test between the + wire and the distributor housing instead. You could also take an ohmeter and connect it between the distributor housing and the enigne block. You should get something near 0 ohms.

I am using the same ground while holding the distributor by using a jumper cable from the install point to the distributor body. I took the pigtail and condinsor out and tested the integrity of wires by moving them around in my hand with a continuity tester and had no breaks in the wire. How much play should there be in the distributor shaft? If any.

I just used an ohm meter betwwen the distributor housing and block .2 ohms

:confused: :confused:

O.K. back up a minute, take a deep breath, whatever is goin on is gonna be so simple it's gonna make ya feel stupid,
First check to make sure ya didn't leave the little metal ground strap off, you'll find it under the coil cover on one of the coil mounting screws and it goes out to the elec. connector boss on the cap if'n it ain't there it won't work. if thats o.k. then another common problem if your running a vacume advance is the pickup wires would break from movement, so when the advance pulls they loose connection, try to start it without vacume hooked up if it runs then replace the pickup... also you can ohm the pickup just unplug it and ohm it out, specs for any G.M. pickup is 500 to 1500 ohms..... But after all that I bet ya left the ground off the coil....cuzz that strap grounds the coil to the housing. the biggest failure is the module and don't trust Autozone for testing or electronic parts.... And don't forget to check the rotor they where bad to burn thru right where the coil tit contacts the rotor blade..

Ter-nan,
Do u have an aftermarket tach? If u do unplug it from the dist, it should be on the left and the B+ should be on the right. I just ran into this at the shop last week. The bosses son had instaled a 350 in an s10 and he had a cute little piece of junk tach. The tach was grounding inturnilly and so there was no sparkles. Try that and let us know.

:confused: :LOL: :whacked:

I have seen where the magnets on the pickup coil lose there magnatism, don't know how but they did.
Homer

Well it's fixed. I changed the capacitor on Tuesday and the spark returned but still no start. Then yesterday noticed that I wasn’t getting gas to the carb. The problem with the dist must have been in the wiring or capacitor itself. The problem with the carb was that at some point I broke the accelerator pump arm off the carb. It was an edelbrock carb and the pump arm sits up in the front left corner of the carb body. I am now running a quick fuel technology’s Q750. Moral of the story, don't become so focused on a problem you don’t stay aware of everything else that’s going on and intermittent problems suck.
Thanks for all the ideas, the truck is running great again.

Terry

:D ATTA-BOY:D