Onewheelpeel

First a little background,so I have this 94 z28, got it in a trade with no transmission, (was an m6) car. So I've been working On putting the engine back together. Fixed the vats with a resistor, security light turns off. When I crank the engine it turns over and there is spark, I verified. The fuel pump is new. It clicks on for 2-3 seconds to prime. Lots of Fuel comes out when I depress the scharder valve. I was able to get it to fire and rev to 2000 with starting fluid, then cuts right off. I have verified battery voltage KOEO at each injector wire with my test light. My next thought is the ground is not pulsing, I don't have a noid light but was able to briefly see imy test light pulse when cranking but was very weak, and then it totally disappears. No oulse at all. To test the injector I removed them clicked them open with 12v and cleaned them with marvel mystery oil and carb spray and re installed them. When applying a ground manually at the each injector pcm pinout, I hear each injector make a nice click. Was unable to find any pulses coming out of the opti. So I bought a new one. It interesting because the 96+ opti fits into my camshaft, the 93-95 opti does not fit.. Thinking maybe I have a 96 motor with 94 pcm just guessing at this point. But even after the new opti installed, still no injector pulse at all.im lost, I have checked all grounds and even tried pinning the ECM with my own new good grounds, still no injector pulse. It should be noted my security light turns off after 5 seconds, all the cluster lights workEXCEPT THE FASTEN SEATBELT INDOCATOR AND COOLANT TEMP WARNING LIGHT. These two lights seem dim. Once or twice they I have seen them at full brightness. Kinda wierd. Service engine light does turn on and work, checked all fuses, I'm stumped. Waterpump is currently off because after I installed the new opti was unable to get it to run. At this point any suggestions would help as I'm about ready to just put a carb on it Thanks in advance

ACE1252

Have you had the car scanned for SES codes? Some codes don't set the SES light.

There are a number of conditions that will not allow the injectors to fire on startup.....trouble with High res and low res signals are one common source of trouble. The harness going to the Opti needs to be checked.

As a starting point, have a look at this video......should help out with Opti diagnosis.

93M6Formula

Just an FYI, the Spline Drive Opti was used from '92 to early '94 (built in late 1993) so all Vented style optis will work on late '94 to '97 LT1s. The dowel pin length on the cam is different from '92-'94/'94-'97.

Check you timing cover for a Crank Position Sensor, it's shouldn't have one if it's a '95 on down motor. If it was a '96 motor in your car, it wouldn't really make a difference. If you put a '94 motor in a '96 without the CPS and associated parts, then you would have a problem.

Also, check out the ground wires that are bolted to the block near the coil and ICM. Make sure they are clean and not broken. There's quite a few in that bundle of wires.

BTC

I may be mistaken, but I'm fairly confident that all 1994 LT1 F-Body's have the spline drive optispark.

93M6Formula

Depends when they were built, I know i've seen a later '94 with the Vented Opti. I'm not sure when they switched over. Somewhere midyear 1994.

BTC

Interesting. I've honestly never heard that, or seen it documented. I've also never been prompted for a build date, or any additional clarification beyond the model year, when purchasing a distributor for my car.