Car starts and idles find but cuts in and out while driving

Car ran fine but had lower intake oil leak on my 2004 pontiac grand prix. I replaced lower intake gasket, valve cover gaskets, upper intake gasket, map sensor, and pcv valve. Car starts and idles fine but when i drive it it cuts in and out. It will accelerate fine at first then it cuts out and the rpms drop and ill floor it and they wont go up, then it will go back up and speed up. It keeps doing this sporadicly. All wiring is hooked up right. Not sure hats wrong. I spayed the fuel injectors out with cleaner while each one was energized. Maybe they clogged up after or do i have a short in a wiring clip somewhere ? Ne help will be appreciated!

Check the fuel pressure.

1 Like

I checked the fuel pressure on the service valve on the fuel rail and its fine. Thats why i was thinking possibly the injectors got clogged after i cleaned them out. Maybe they didnt fully blown out and they blocked up or got stuck open when its not cutting out it has good power, but its doing it alot. I was thinking a short in throttle body connector messing with the peddle sensor but it revs fine in park… no engine light either unless the cose is pending. My code reader broke so i cant check.

Was it 65 PSI or 35 PSI ?

There are so many causes for this,its impossible to enumerate everything.This article will give you a good base for troubleshooting your vehicule.

have you changed the fuel filter?

04 Grand Prix fuel filter change- Silent Video - YouTube

1 Like

Im pretty sure i got a faulty brand new map sensor from the store. I unhooked it and it runs fine.

1 Like