Car will turn over but won't crank. It tried to hit a couple times then just turns over. Checked the fuel pressure. Pressure is fine. Sounds like its not firing. Turned it over several times & nothing. I tried to scan it for codes but found none. If its an opti failure, wouldn't it throw a code? Thoughts?

 

check for spark.there is a sticky at the top on how to test the optispark

 

Pull the coil wire out of the opti and check for spark. If you get spark then the coil and icm is good. And chances are your opti is out.

 

The Opti only sets codes for failure of the optical sensor. It doesn't set any codes for a cap/rotor problem.

 

Thanks guys. Update. Fuel: Checks good. approximately 40 psi at prime & close to 50 psi when cranking. Spark: Checked it on one. Its getting spark but seems like a long pause between the times it fires. Car does try to start initially then dies. Sometimes diesels after I stop cranking it. Gonna do Shoebox's opti check tommorrow.

 

Update. Checked the Opti. It seemed to be OK according to Shoebox's test. This is a new AC Delco opti with 50 miles on it. However, just to eliminate the opti as the culprit, I swapped over to a working Cardone unit to check it. Tried again, same problem. Car starts for a second then dies. If you try to start it again, it will not start.

I checked around & noticed that the hot wire from the Racetronix wiring harness had fell against the passenger side header & partially melted to the header. I cut the zip ties holding it loose, pulled bad section of wire to where I could cut it out. Cut it out, then spliced the 2 wires together with a 10 gauge butt connector. Tried the car again. Same exact problem. Again, the fuel pressure at priming comes up to about 40 PSI. When the car is cranking it shoots up to about 50 psi.

Would the wire melting have caused the relay and or pump for that matter to have burned up? The pump comes on like it normally does (sounds identical to the way it was working before). All fuses are A-OK. Check all of them (& double checked them including the one sent with the Racetronix wiring kit). The fuel pump is the unit sold by Racetronix (which I believe is a 255 lph Walbro unit). Any thoughts? I have went a head & ordered a new wiring harness with a new relay.

 

Went out there & checked again. I hooked up my fuel pressure gauge & turned the key to the on position. Pump Primes up to 50 PSI & the Pump seemed to STAY ON. I tried cranking it a couple of times & the car would not even attempt to start. When the key is ON the pump seems to stay on. Pressure holds at 50 PSI until that whole time. When I turned the ignition OFF it drops to about 37-38 PSI.

 

To crank it to much with out spark, you'll foul out the plugs. Pull the PCM BAT fuse out and crank the car to get the excess gas out. Then put the fuse back in... I think the PCM BAT fuse is under the hood in the fuse box... I know mine is inside my car.

Did you check the copper ground strap? what about the wire harness to the coil pack ICM? Maybe the wire cracked and broke and you just cant see it.. Inspect the harness

 

The coil & ground straps are OK. This all materialized after I found the burnt wire.

 

Just did a coil continuity check. 8250 ohms. Spark is fine. I think this is fuel related. Its coincidental with the wire getting burnt. How MIGHT this affect the relay other than making it fail go contact. After doing a search this seems to be something that has never happened to anyone before.

 

This is for a 1996 Z28.

 

I had the startup and then immediatley die problem. My particular problem was the intake elbow not completely sealed onto the throttle body. I had removed it to make room for me working on it.

Also make sure the silencer at the bottom of the elbow didnt break off, that will also cause the start and immediatley die problem.

 

Its NOT something to do with the CAI, MAF or the like. The car was running fine until the wire got burnt.