I have an '89 Camaro IROC, 305 MPI, 125K miles with a rebuild before I bought it. Car is very well maintained and ran flawlessly until 2 weeks ago. Now, when I hit the gas, it bogs down, sputters, pops, farts, and goes nowhere. If I only give it a little gas, it will go, but it is still hesitant. To me, it seems like its not getting enough fuel. I have changed the TPI, the Mass Air sensor, and last night I changed the fuel filter. While doing so, I checked the pressure to the filter and it is good. All the injectors seem to be firing as they should and I'm not getting any misfires. Any ideas? Thanks in advance.

 

It does sound like a fuel issue.

Not sure what you mean by "changed the TPI"...

Do you have access to a volt meter? i would recommend back probing the TPS looking for the correct initial voltage and smooth operation during transitions.

 

Sorry for the typo. I changed the TPS. Got it tuned to specs, .54 I believe it was, and it did nothing to solve the issue.

 

What is the fuel pressure WHILE IT'S IN THE ACT OF SCREWING UP? Not while sitting in the driveway idling; WHILE IT'S IN THE ACT OF SCREWING UP. Driving down the road, you give it gas, it sputters, what is the fuel pressure AT THAT EXACT INSTANT? I cannot emphasize strongly enough, you need to know what the fuel pressure is WHILE IT'S IN THE ACT OF SCREWING UP. What it's doing while idling is irrelevant and USELESS.

In case I wasn't clear: measure and report the fuel pressure WHILE IT'S IN THE ACT OF SCREWING UP. Tape your gauge to the windshield and go make it SCREW UP, and tell us what the gauge reads WHILE IT'S IN THE ACT OF SCREWING UP.