1991 Camaro won't start

I have a 1991 Camaro RS 5.0 that will not start. I have replaced the plugs, plug wires, distributor cap and rotor, pick-off coil in distributor, coil, MAP sensor, electronic spark control module and ECM. I am getting a spark that is very weak. All 8 cylinders measure 145 +/- 5 psi compression. I need help. The spark is so weak it will not fire my timing light. I am getting gas to the TBI, strong flow and good pattern. :banghead:

If you used an AC Delco module you next steps are to make sure you have 12v (=/-2v) going to the distributor. Then ohm out your coil (you'll need a manual for the proper readings). If it checks out you'll need to check the secondary coil. It is down in the distributor near the reluctor ring, also check the reluctor ring to ensure it is mounted firmly, not broken or corroded.

Even though the coil and spark module are new I had them checked and they tested good. The secondary coil in the distributor is also new and the distributor was cleaned up when replaced. I checked the output from the new ECM to the spark module and am getting a good square wave. Still the spark on the plugs is very weak. :banghead::banghead:

If it helps, I went nuts chasing the same problem around for months with the same results, finally I broke down and went to replace the coil with another one just for the giggles and found the carbon button was scorched.

Wrightz28 - Do you mean the button on the distributor rotor? When I replaced the cap and rotor, I bought Sorenson instead of AC Delco. Could this be the problem? My timing light will not fire when connected to the plug wires but will fire when connected to the coil wire leading to the distributor. :confused:

yep, miine is a intagrated coil in cap, but same concept.

Replaced the cap and rotor again with AC Delco. Still will not start. The timing light will not fire on the plug wires. It fires irratically on the coil wire. Is there a way I can change over the ignition to run without the ECM? I live in South Carolina and the Camaro is a 1991 and I do not need to pass inspections. What can I do? :confused:

Replaced the cap and rotor again with AC Delco. Still will not start. The timing light will not fire on the plug wires. It fires irratically on the coil wire. Is there a way I can change over the ignition to run without the ECM? I live in South Carolina and the Camaro is a 1991 and I do not need to pass inspections. What can I do? :confused:
The ECM has no control over the ignition except to advance or retard it. If you don't have spark at the wires then you either aren't getting enough voltage to the distributor or one of the components in it is bad

Did you check the bats on the distributer?

Bats? :confused:

Is the "security" light staying on longer than a few a seconds?

Bats? :confused:
The wire connectors on the distributor.

You did put your origional prom into your new computer, right?
Also, how are you checking your timing if your car will not start?

The wires on the distributor are snapped into position securely. I don't know about the security light, I'll check it tonight after work. Timing - I put cylinder one at TDC on the compression stroke and set the distributor position for plug one facing the front of the motor. Yes, I did put the original prom into the new ECM.

set the distributor position for plug one facing the front of the motor.

I think in this llies the problem. The wiring connectors, "bump" if you will on the side of the distributer s/b at a 3 o'clock postion roughly to be close to 0*.

If you turned the dizzy that much it's like 5 o'clock right? waaayy off.

Chances are you have a key with a resistance pellet in it. Set your mulitmeter to ohms and put one lead on each side of the key. You need to find that resistance on the GM VATS code list (1-15 all different resistances). Then you need to go here http://ecklerscamaro.com/ and buy the security system override, its like 30 bucks. Pull the hush panel off underneath your steering wheel and plug it in. Problem fixed. Go here to find your VATS code # by resistance. http://www.likeabigdog.com/column/VATS.htm

Sorry Tuffdrvr, but I dont think his problem is the vats because his engine is turning over. BTW: I have the system override from ecklerscamaro too...:grinyes:

Turns out that I was sold the wrong plugs and they fouled out. :screwy: When I replaced the plugs, the car started right up. :grinno: I still have a problem, the car seems to be running rich and choking out. I replaced the IAC and O2 sensor for grins. :grinyes: The fuel regulator on the TBI clicks when the key is on and the engine is not running. Is this normal or could I have a fuel pressure problem? :dunno:

replace the fuel filter and see what that does. check the fuel pershure also after you do that.

Does it just click when the engine is priming, or does it just continuously click?

The pressure regulator clicks continuously when the key is on.

Possibly a bad map sensor?