I have a 1990 IROC-Z with the 350. I am having a hard starting problem on it. Sometimes I have to crank it alot of times before it will finally start. When I turn the key I can hear the pump kick on for the 2 seconds. When the car does start it will run for about 5-10 minutes and start running pretty rough and die sometimes. It has a adjustable fuel pressure regulator on it and the guage will show about 6 psi when the car is running. I am hoping that it is just a relay but I am thinking maybe not. Also I did put a new battery in it so that is not it. Anyone had the same experience or know what it may be? Thanks

 

Could it also maybe be the fuel filter? Thanks

 

How much does the gauge show when you turn the key on and the fuel pump primes?

If only 6 psi, it's way too low for TPI. The injection system requires 38 psi at idle and 43 psi at WOT to run right.

Lou

 

When I first prime it I think it gets up to around 10 -16. So what would that point at?

 

Is the car carb TBI or TPI?

 

It is a 5.7 TPI

 

You may try and raise the pressure on the regulator, but as others said, that is way low for TPI.

 

Way too low. If you can adjust it to 43 or so that's fine. Otherwise it's time to figure out why it's so low. Possibly time for a new pump.

 

An easy check to eliminate the FPR or fuel pump:
- engine stopped, key off
- run the fuel pump continuously (you can use the standard paperclip trick)
- adjust the FPR to achieve 43 psi - if it works, test drive it
- if you cannot achieve 40+ psi, take vise grips and momentarily clamp the return fuel hose - if the pressure doesn't change (it should shoot up to 80 psi at least), the pump is bad

Hope this helps.
Lou

 

I changed the fuel filter today. When i blew it, it came back out on my face so it was REALLY clogged. I drove it around for about 15 minutes and it seemed to run fine so I believe that fixed it.

 

What's your pressure now?

Also, if the fuel pump ran for some extended periods of time with this clogged filter, make sure you test it long-term because it might now have some internal damage from the extra strain.

Lou