Thread: Misfire when car warms up and no boost

Did you check fuel pressure in the morning or when it wouldn't start? With the car ideling the fuel pressure should be between 45 and 55 psi.
You may want to check the fuel pressure while it's acting up like when you have to give it pedal to keep it running. This will tell you if there is a fuel issue.
Is this what you've done?..cause 20 psi will not only cause a lean condition, it's not good for the engine.

If the pressure is in fact 45 to 55 psi when running then move on to what these other guys have suggested.

20 psi while running:
I understand why you asked about pressure at the pump but check the voltage at the pump first. It should be over 13 volts. If it's only 8 or 10 volts then you'll probably have to install a fuel pump rewire kit.

If the voltage is correct then I would suspect something wrong with the regulator. Did you remove the vacuum line when you "disconnected" the regulator?
I don't think this a sure-fire way to eliminate the regulator as a possible suspect.

Heat soaked electronics:
When you park the car the latent engine heat can wreak havok on many electrical components, ICM, CPS etc.

Hope this helps.

Hey guys I am back. I finally got it fixed. It was actually the new A/C Delco fuel pump. I whent to the local junk yard and bought an entire A/C Delco fuel pump assembly for about 31.00, and once I put that baby in all problems solved. Pressure is at 48 psi when ideling and I have been driving it know for about 4 days with no check engine light and my mileage has gone up from 11 mpg to 17 mpg city driving. Thank you all so much for all the help. I should have never assumed that a new pump would not have been defective. Again thank you, and hey now after all this I know for sure that I have no vaccum leaks at all!!