Hi all, got an 86 camaro job - has no tach on the dash. Cranks but has no spark (none/zero any time). New items: coil, entire distributor, ecm, wires. I have tested all the ecm points with key on, right now the only "off" item was TCC circuit reading, I removed it from the picture still no spark. I have all good fuses, B+ at coil, B+ at appropriate points at ecm, and both ecm ground circuits measure .6ohm or less (my test ground may have been less than ideal, I was expecting .4 or less). Going back over the factory service manual I am finding not everything in the manual is 100% correct (like 2nd system ground at ecm is black with white, manual says should be tan with white). I have solid light/b+ when testing at a injector while cranking, indicating basic hei problem amongst the other book tests. No spark from any plug or direct at coil (via wire) when cranking, not even anything jumping to ground. I have tried adding a distributor ground via a cap screw to be sure that was good with no change. A little surfing has me wondering - I have 20.8 ohm at tach lead circuit at the coil (disconnected from coil) but vehicle has no tach, and, I have read a shorted circuit here has caused issues for others. I have tried MAF disconnect per manual as well, no change. Anyone have any helpful thoughts or directions to suggest from here? My newer model thinking is telling me the data list must be missing something but the manual keeps pointing to a basic hei problem, and considering the vintage the graphed out voltages I have done a few times now is probably all the data list would show anyway?

ADDED: fuel pump is working fine, 2 sec at key on, I smell fuel while cranking at times and hear the pump no problem.

 

Hi betterzenguy,

Just a quick point of correction here; The 2.8 is not "TPI" (Tuned Port Injection), that was the 8 cylinder cars. The 2.8 V6 was "MPFI" (Multi Port Fuel Injection).

It looks like you have checked/replaced pretty much everything responsible for creating sparks, but there is one item I don't see mentioned in your post;

While you are cranking the engine, have you visually verified that the distributor is, in fact, turning? I've seen more than once people with your very same set of circumstances end up discovering a bad timing chain to be the culprit....

 

Thank you for the correction, my memory was seeing the "tbi" on the top corner of the page when I started writing, it does just say "port" in the manual.
Cap pulled, it's moving.

 

If anyone's wondering. .5/.6ohm is found at: both circuits on the coil/ICM sub-harness; all 4 circuits from ICM to ECM. All circuits at ECM tested with key on appear to have correct readings per the service manual. ECM grounds are both .4 .3 as tested. I added a direct path to ground for the ICM via a distributor cap screw and the coil via its metal body, individually, with no change.
The manual seems to allude that the MAF is the only other "must have" item for ignition control and the test for that is simple enough and made no change.