I think based on what I've read from the posts I've searched that I may know what the issue is but wanted to put it into a post to see.

Here's the trouble. I have a 95 z28. only mods are SS airbox and exhaust. I had noticed some hesitation when accelerating lately, put some fuel system cleaner through it and it went away except when cold, then it was only faint. I drove the car yesterday, had no issues. Today, I get in it to leave and the car will turn over strong, but no spark at all. the first time I tried to start it, there was an unsual noise from the fuel pump. It was louder than normal and seemed to have a vibration you could faintly feel. I checked the schrader valve and there was no fuel there when release valve was pressed. No fuel there while turning over either. So, what I've been reading it may be the check valve. Does this sound right? Or should I be concerned about some kind of internal failure in the pump due to the noise I heard?

 

The check valve in the fuel pump only holds the pressure in the system when the pump shuts down. It will not prevent the pump from developing pressure when its operating. Put a fuel pressure gauge on it.

You also indicate you have no spark. That would not be related to the fuel pump. Is is possible you have a code like DTC 16, which will prevent the engine from starting? Have you scanned it for codes?

 

Ya, that would be the best case scenario, by putting the gauge on there. I don't have that or know anyone that does. In regard to the spark issue, I'm not sure if there is spark. I guess i shouldn't have used that word. It's just not firing up. I guess that's a better way to say it.

 

Well you 3 things to run a motor. Air, spark, and fuel. Of course there are other things too but as soon as you can rule out you are getting 2 out of the 3 life will be a lot easier. Get yourself a fuel pressure gauge- it will come in handy down the road for doing other things too...

 

Diagnosis, fuel pump. UGH