gradyrowe

I have a 1989 corvette (automatic) and the car will have a rough time starting and then when is does start you have to feather the gas to keep it running. when it warms up it will run fine and idle very smoothly and then once it gets too hot then the car starts to idle rough and eventually dies. any ideas? any input would be greatly appreciated!

antfarmer2

Have you changed the air and fuel filters lately

gradyrowe

yeah I bought a new air filter and a new fuel filter and the sending unit that holds the fuel pump. im thinking its some kind of sensor or a vacuum leak, I tried to check the codes but it doesn't send me any.

antfarmer2

Did you put a new rubber line from the fuel pump it can crack and cause this and needs to be the right kind of hose. can you put a fuel pressure gauge on it?

gradyrowe

the sending unit came with the rubber hose so that's brand new and I haven't tried to out a fuel pressure gauge on it. its getting plenty of fuel to the fuel rail so I don't know what to do.

antfarmer2

When did this start before or after the parts? See what the gauge tells you.What is the pressure with the key on then started then with a vacumme line off. Then turn it off and see how long it holds mine will hold all night

antfarmer2

Pull your vacumme line off your fpr and smell for gas

gradyrowe

what and where is the FPR? i don't know that much about cars if you cant tell

JrRifleCoach

You need to know how much pressure.
The FI system needs pressure, not "plenty of fuel".

To help you out we need information. Its that simple. The Fuel Pressure Regulator FPR has a vacuum line connected to it. When checking the FP pull this line to see if FP changes. Then watch FP at idle and as the throttle is bumped. Should be around 38 and jump to 45 when bumping the throttle.

Report back the pressures your seeing. There will be others chiming in here.
Cliff Harris is the guru here. Pay attention and he will get you through this.