Hello everyone. I have been dealing with a no spark situation for the past month. I had a fuel leak problem as well but I was able to fix that by making my own steel braided line. Now this is what I did today. FYI, this is an HEI system on a 1970 Chevelle 396. I replaced the ignition module with an NOS unit. Now, I don't know if this was a bad idea because someone had mentioned that modules like this have a shelf life and I maybe should've just gotten one from Autozone. I cranked to see if that fixed it and still no spark. Next, I wanted to change the coil that's in the cap. While I was loosening some screws, I figured that I would make sure that the plug wires are all going to the spots they should be. Whichever mechanic last worked on this car set up every single plug wire in the wrong cylinder. This car hasn't started for 3-4 years so that's the last time someone worked on this car, and it wasn't me. So I fixed the location of all the plug wires and tried cranking to see if that fixed it; still nothing. Next, I took the coil out of the cap and tested it both ways with a multimeter and it passed both tests. I had an NOS cap and rotor so I installed those and moved the coil to the new cap just in case there was an issue with the cap and rotor. Put everything back together and still nothing. A week ago, I had a friend who was cranking while I had a plug out to see for spark and there was no spark. I was alone this time but I didn't hear the engine "catching" at all so even though I didn't have a plug out today (because I couldn't do the plug test myself), I know that there is still no spark. It was just cranking and cranking and cranking. I tested the battery wire that goes to the BAT side of the distributor and it was getting battery voltage. The TACH side has nothing plugged into it but I don't think that will cause any issues. The battery is brand new so there shouldn't be an issue there although it needs to be charged because I drained it from all the cranking. I don't know how to test the pickup coil but is that what I should test next? Should I get a new ignition module because maybe the NOS ignition module I got wasn't a good idea because of the whole shelf life thing? Could it be a fuse? The rotor is spinning because each time I took the cap off after cranking, it was in a different spot. Also, the ignition coil setup was missing the piece I circled in the picture attached. Could this cause the issue or not? Any help on what to do next is appreciated. Thanks!
1970 Chevelle 396 HEI Ignition No Spark
- Thread starter 340 RR
- Start date
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67Dart273
Well-Known Member
If you cannot do anything else, pull the dist out lay it on a bench and find some alligator clip jumper wires. Consider pulling it apart if necessary and connect back with the jumpers and device a way to get power to it. These are essentially a Mopar 4 pin box all packaged up. What I mean is they work very very similar.
You have a module which must be grounded, and of course that is the dist. case, so the case must be grounded
You have 2 pickup wires just like Mopar, and you have a 12V power to the box which also feeds the coil primary.
Last, the cold or switched end of the coil goes back to the module.
It has been decades since I've had one apart
Scroll down this page, there's a helpful chart down towards the bottom:
You have a module which must be grounded, and of course that is the dist. case, so the case must be grounded
You have 2 pickup wires just like Mopar, and you have a 12V power to the box which also feeds the coil primary.
Last, the cold or switched end of the coil goes back to the module.
It has been decades since I've had one apart
Scroll down this page, there's a helpful chart down towards the bottom:
Yup. That center piece is the ground. Won't run without it.
It installs in the center slot in the HEI cap plug well. You have to remove the coil and it installs under it.
Thank you for the info 67Dart273 and RRR. I will take a look at that document that you linked. I forgot to mention RRR, the ignition coil didn’t have that piece that I circled but it did have a second ground that was a pin on one side that connected in between the yellow/white wires and got grounded by another one of the coil hold down bolts. So I assume that the second ground takes the place of that piece I circled. This car started 3 years ago and even though that’s a long time, it hasn’t been messed with since then. Like no one would’ve removed something that would prevent it from starting. So since it started, 3 years ago, with that second ground strap that I noticed today, that part must be fine. Sorry again I didn’t mention that. I’ll have to do some more tests with the multimeter. Thanks guys
Alrighty.
If the vac adv was hooked up, the p/up wires flex & will eventually break. Check the p/up wires [ disconnected from module ]; they should measure several hundred ohms. Wiggle the wires while testing.
With HEI, the body of the dist has to be grounded to produce a spark [ unlike Chrys elec ign ]. Make sure the dist clamp is making good electrical contact with the dist flange.
With HEI, the body of the dist has to be grounded to produce a spark [ unlike Chrys elec ign ]. Make sure the dist clamp is making good electrical contact with the dist flange.
When this was converted to HEI from points, how was it wired? Does it spark/run if a jumper is added to the HEI directly from the battery? When I converted a '69 442 'vert with a 455 to HEI in the '80s, I replaced the resistor wire in the harness and added a jumper from the R terminal on the starter.
Another quick question. I pulled this picture from another forum post online, it is not mine. Ignore the red circle. Is there a possibility that this is a fuse issue? If it is a possibility, which fuse should I look to change? Is there a way to test if the fuse is bad? I am familiar with fuses for newer cars and how to see if they've gone bad but I've never dealt with fuses like these. Thanks guys!
How in the heck would we know? You have the car. Have you thought about actually looking at the fuse box? Maybe testing the fuses with a test light? Come on guy, you're gonna have to have some skin in this game.
All I can tell you is, you MUST have the ground blade in that center slot on the cap. If it's not there, no run. There were two different styles. One used the separate grand strap with the hook that installed under the coil. The other had a made on blade that was soldered to the ground wire on the coil. The ground wire attached to the coil and the ground blade was soldered to the same wire. If that center blade is not present, or if it is not attached to the ground wire, it ain't gonna run. Period.
Thank you for the info RRR and LO. RRR, I didn't mean to word my question the way I did. I meant is there a fuse in the fuse box that could cause a no spark situation. If there is, which fuse could it be after looking at that picture which shows what each fuse controls. I'll find a test light and check to make sure none have blown. Shouldn't take long to test each one since there aren't too many. Thanks guys
NoCar340
The Original Partstitute
I think what he meant was we have no way of knowing how the ignition was wired into a car that wasn't born with it. Essentially, you're asking where the fuse for the MSD 6AL would be on a '67 Dart. Just test the voltage on the power wire with the key in the run position. If you have battery voltage (or near enough) at the hot wire with the key on, and everything's in order inside the distributor, you should have spark. If the ground strap you circled is missing or the module wires are broken, you won't have spark. The module wires often look OK but are broken inside the insulation. The ground strap gets left out by accident.
Chances are if you changed the module to repair a no-spark issue and the new one didn't do it, the module wasn't the problem.
I've never heard of a "shelf life" on an HEI (or any other) module, new or aftermarket. They don't spoil. If it was truly NOS GM--never installed, i.e. no scratches on the terminals before you installed it--it would be rare to get a bad one.
I see, that makes sense. I apologize for the bad questions. Could you explain where I would find the power wire? Is that the wire that is connected to the BAT terminal on the distributor? Thank you for the info in regards to the "shelf life" of the module. I was told that a lot of these NOS parts do have shelf lives so I was questioning as to whether I shouldn't have gotten an NOS unit and just went to Autozone and picked up one there. Thanks everyone
Dartswinger70
Well-Known Member
Its been a while since i worked with GM hei but how is the cap and rotor? as far as black burnt work marks on the rotor and the carbon "button" in the cap?
While I was changing the ignition module and testing the coil on the cap, I decided I would change the cap and rotor since I had also bought NOS of both. I changed the ignition module to a NOS module, and the coil tested fine so I put it back. I also tested the wire that goes to the BAT terminal on the distributor to make sure that it was getting battery voltage with the ignition on and it was. I think my next steps are to check the magnetic pickup and to make sure that the distributor body is grounded.
Exactly.
Correct. You're just going to have to physically trace it and see where it goes.....but did you not say you're getting 12v there? If you're getting 12v AT the distributor, I'm leaning toward a bad ground.
Yes, I did say that I'm getting 12V there. I just wanted to make sure that that is what was meant by power wire. I'll make sure to check ground where the clamp gets bolted to the flange. I'm confident that everything else is set up properly. Thank you everyone!
slantsixdan
=..=
That is not so. They do not degrade or expire from sitting on a shelf. But you do have to make sure your coil, pickup, and module are correctly matched; read the second post in this thread (and yeah, the ground strap has to be in place or no vroom)
Those are poorer quality than the ones made years ago.
That is what I thought and that is why I went NOS but just wanted to confirm because a friend of mine told me about shelf life. Thank you
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