Ok I've got a '96 Z28.

When trying to start the car, it takes many attempts to get the motor to start, sometimes 10+ key turns while letting it crank about 2 seconds each time.

Most of the time when it finally starts up (it does start up every time it just takes a while), it has to build up to idle real slowly, running real choppy and rough about 300-400 RPM below normal idle. It builds up to normal in a couple of seconds and then idles fine.

When running steady through the RPM range, theres a real bad lag at about 3000 RPM before it starts revving back up normal again. It also doesnt seem to run with as much power as it used to.

Replacing plugs, wires, and opti didn't do anything to help.

Please give me any and all ideas that ya'll may have. This thing is driving me crazy. Thanks!

 

Any scan data or trouble codes? What is your fuel pressure?

 

Been trying to find someone local with a fuel pressure gauge. Is there somewhere to rent one or are they available from loan from an Autozone/Advance?

Do have SES light, but havent been able to make it to get it checked for codes yet. Hopefully I can get that done Monday. Probably should have started with that, but it seems like when I had it checked before it was something irrelevant.

 

Unless you want to get nickle and dimed to death by dealers and shops, you need to get your own tools. A fuel pressure test gauge is no more than $35. A cheap OBD-II code scanner is under $50. They will pay for themselves many times over.

When you try to start it, will it start easier if you put the throttle on the floor BEFORE you turn the key to start it, and hold the throttle on the floor until it starts?

 

Just tried this a few minutes ago, and it didn't start any easier than with no throttle.

 

Ok I had forgotten that there was was a Hypertech tuning on the car (came with it when I bought it).

I just hooked up the unit to the car and put all settings back to stock, and the SES light doesn't come on anymore.

Still have the same starting issues however.

 

Fuel Pressure when key is in on position: 7-8 PSI

Fuel Pressure while motor is at idle/light driving: 30-32 PSI

Fuel Pressure at WOT under load: 20-22 PSI

anyone tell me what to do based on that?

 

Fuel Pump is shot. You should be in the 42psi range.

Replace your Fuel Pump and Filter. Should solve your issues.

 

Try the filter, then the pump.

 

replaced the filter a couple of weeks ago. Didnt change anything

 

Ah, would have been nice to include that info before someone went to the trouble to suggest it.

 

Sorry. Forgot about it til it was mentioned or else I would have

 

Hard starting can be a sign of a bad fuel pressure regulator. Check it out before changing the fuel pump...

 

is the only way to check the FPR to check the vaccuum line for fuel or the smell of fuel?

 

is getting a new fuel pump from a parts store a bad idea?