Mharvey33

Hello, I've got a 94 z28 with some problems...It doesn't start.
I recently replaced the head gasket, when I did this I reworked the heads. When I put it all back together it ran like a top. 1 minor vacuum leak but besides that everything was great. I drove it around our neighborhood block, all good. I got into the driveway and it died...It did start back up but ran like total crap? Like it was coughing and struggling to stay alive. Ever since then it would not run like it should. In the attempt to get it running heres what i've done..

Timing Chain
Optispark
Knock Sensor
Ignition coil
Ignition Control Module
Water pump
Spark Plugs/wires.

I need some help now I'm quite desperate lol.

Injuneer

Have you scanned it for codes, or checked the fuel pressure? Have you checked for spark at the coil wire? .....at the plugs? What brand Opti? Did you loc-tite the rotor screws?

Mharvey33

I have scanned the codes, have not checked fuel pressure, It does have spark at the coil wire, have not checked spark at plug wires. Codes are 42,43,44,45,51,53,54,55

Injuneer

What brand scanner did you use? That looks like the usual incorrect code list from an Equus scanner. For some reason they don't work on our OBD-1 PCM. There is a link to a free download of 94/95 LT-1 OBD-1 scan software in a "sticky" thread on the"Computer Diagnostic......" forum.

Mharvey33

I used an Innova 3120D. Had good reviews so I bought one.
What should the fuel pressure be at before start. I have a gauge to check it now.

Injuneer

That's the problem scanner..... not the Equus (aging memory - my fault). I've seen at least 1/2 a dozen people post the same code list. At least one of them is not even a valid LT1 code. Two of them contradict each other.

The fuel pressure should reach at least 40 psi when the pump shuts off. It should hold that pressure dropping off very slowly.