It happened again today. Pulled all relays, will not solve the problem. Something is not stable, that's all I can say. But I don't know what is it.

 

 

shparts this is the same problem i am having and i cant figure it out so as soon as you solve the problem explain to me how you did it thankyou.

 

Let's see, the whole thing is getting wireder and wireder. As the Z is doing what it's doing-will not start periodically and I am not the first owner of the car, so I kind of think there might be something going on with the ECM. I took it out and opened it, and not surprised to find a Jet Performance Stage 2 chip on the stock GM chip. I hate chips! For all the cars I own, they always create problems. I unpluged the chip, put the ECM back into the car, it starts right up. However, it feels like harder to start and sometimes I gonna have to pump the fuel a couple of times to start.

I was thinking since without the performance chip the engine does not need that much fuel for peak power, maybe I give it some time for the ECM to re-learn everything.

Within 24 hours, car became really hard to start. My original problem is no spark out of coil, now I've spark, NO FUEL. When I turn the key on, the pump will come on. But when I crank the engine, the pump will not stay on. I bypassed the ignition and keep the pump stay on, still no start. I noticed there's no fuel out of injector. Btw, the engine will start on ether.

Frustrated.

 

test the tps and map. check the fuses for the injectors. have you put a noid light on the injector plug to see if they are being told to fire by the ecu.

 

i didnt read all the replys but if not mention turn on the car and disconnect one battery cable it should stay on if the alt is charging, also check your grounds

 

^^^ dont do that you can damage your alternator unhooking the battery while the motor is running.