Car cranks but won't start.
 

A friend of mine has a 99 z28. The engine is stock with the exception of an slp lid, smooth billow, egr and air delete and catback. Sometimes when he tries to start the car it just cranks but won't fire. He said the previous owner had the crank replaced at like 3,000 miles, and the pcm and maf sensor were replaced too. Anyone know why it's doing this? It's got us all stumped. It wouldn't fire at all tonight after about 10 minutes of cranking, unhooking the battery, reseting the pcm, and whatever else we could think of I scanned it with HP tuners and found a code for EGR which was expected since he took off the pump. As soon as I unhooked the laptop though it fired up first time. Anyone know what could be up with this car cause it's got me stumped.

when its not starting, what is it doing? is it getting spark? fuel?

Three requirements to run:
1. air,
2. fuel,
3. spark.

You must diagnose each one until you find the problem. :cry:

well it's cranking so he's probably got spark, even if it's not fireing on 4 of 8 cylnders it will still start, I know this first hand, It will start with a bad MAF it will run shitty, it will also run without egr, I would start with the fuel system, I would start at the fuel pump and work my way up.

just because its cranking doesnt mean he has spark