Putting this in here as well to see if anyone has any advise.

Finished doing an HSR swap that included a new small cap distributor (Petronix Flamethrower) with external coil. Got the needed wiring conversion harnesses from EFI solutions. Went to fire up the car to set base timing and no start. Cranks, no spark. No spark from ignition coil.

Ignition coil has 12 volts with key on. Distributor has 12 volts with key on. Tested ignition coil and its good (its brand new) and even replaced with a spare I had around and still no spark.

Next checked and tested the Ignition Control Module, it passed (again it was brand new) and verified with a new one as well with no change.

I now have tested the Pick Up coil, it ohmed out to 894 ohms which should be fine. Checked resistance between coil and the distributor body and thats infinite as it should be.

I have no clue why I have no spark.

 

Does your tach indicate the engine is rolling over? (I don't recall if they do that or not....)

Is the coil ground circuit being triggered at all? Could test it with a test light, see if the harness is bad?

 

My tach has never indicated my engine is rolling over. Even before I did the HSR swap.

Coil ground circuit, where is that located? I'm looking at wiring diagrams it doesn't show anything other than the distributor grounding itself? What wire is the ground circuit?

 

Yes ensure you have ground at the distributor and the coil.

 

Make sure you have a good ground path through your distributor to your motor. Seeing you just changed the manifold and that is where the distributor grounds through (new gaskets and thread sealant or anti-seize), I would concentrate there first.

 

Rechecked all my grounds, all grounds on the back of the harness are bolted to the rear cylinder heads. Ignition coil has a ground strap bolted to it to the intake. If the distributor itself isn't grounding... All thats in between the distributor is the small gasket.

 

the dizzy should ground to the intake manifold that's the one that really counts. Did you do something with your hold down? Have you actually ohmed out between the engine block and the distributor at all?

What about validating the wiring to/from the ignition module? Including the reference below. One thing I will say is that I have never had the module bolted directly to ground it just runs through the dizzy body. The only wiring you TRULY need is the pick up and the +/-. It will run without the ECU stuff. try pulling it and seeing if it starts working.

Also, there's a red/black wire that comes off of the HEI module that the 7 pins don't have. Is that hooked to a really good ground?
Shouldn't matter but figured I"d ask.

 

I'm using 2 washers on the dizzy hold down bolt. Could that be causing an issue? My DVOM meter took a crap last night and I was unable to ohm out the dizzy to the block.

I am using EFI Connections wiring harness adapters to go from an in cap coil to external coil. I was also under the impression the ICM needed 2 grounds. The dizzy and the pulse reference ground in the ECM.

I used my test light to check for grounds in the 4 wire connector from the ICM module to ECM, and nothing lit up while cranking.

 

You changed the manifold, new gaskets and thread sealer/locker. These materials do not conduct electricity. The ground issue could very well be between your manifold and engine block, not necessarily the distributor to manifold connection. Just a thought.

 

Distributor touches the cam, oil pump. If the engine is grounded the dizzy will be

-- Joe

 

All harness grounds are grounded to the rear of the cast iron cylinder heads. Ground strap from firewall is grounded to the cylinder head as well.

 

http://easyautodiagnostics.com/gm/4....ed-icm-tests-1

 

Took the Petronix ICM to the local parts store and had it tested. Passed the test all 5 times. And I still temporarily swapped it out with another new one just to make sure (this was before I replaced the pickup coil).

I'm totally lost as to whats the issue.

So here is a recap.

My camaro had a large cap and coil dizzy. I converted using EFI Connections wiring harness adapters to a small cap external coil setup.
Distributor is brand new, Petronix Flamethrower.
Ignition coil is not firing its secondary wiring for its 50,000 volts spark.
Ignition coil tested good and even swapped it out with a spare I had.
I have 12 volts to the Ignition coil key on.
I have 12 volts to the ICM with key on.
ICM was tested at a local parts store and it past the test (5 times).
Installed a new pickup coil.
Bench tested new pickup coil. Put out .735 AC voltage
Installed a new ECM.
All grounds on back of harness connected to the rear cylinder heads.
Using a test light I probed the 4 wire connector going from the ICM to the ECM checking for grounds. Nothing lit up while cranking.

 

You might want to verify the colors or that the large to small cap wiring is correct. The letters on the icm connecter will match this picture.




This is the flat 4 Icm connecter, the adapter pigtail will change the order on the small cap icm to
Large cap hei icm
A wht to D
B ppl/wht C
C tan/blk B
D blk/red A

 

The connector going into the ICM reads white-D, ppl/wht-C, Tan/blk-B, blk/red-Athe 4 way connector on the engine harness side reads wht-A, ppl/wht-B, tan/blk-C blk/red-D

I just got back from vacation so time to keep plugging away at this thing. I purchased a new test light as my jury rigged one wasn't cutting it. From what the wiring diagram shows the purple/white wire is the pulse ground reference from the ICM. Backprobing this wire while cranking resulted in the test light pulsing.

I'm really hoping to figure out this soon for the weekend. Not sure what else to check.

Edit: Swapped in another distributor with the same results. I have no clue what else to do now.

 

Fixed my DVOM meter and started rechecking wires. My continuity tester said everything was good. But when I ohmed out the signal wire that goes from the ICM back to the coil it ohmed out high. Rewired that connector and the car fired right up.