85berlinetta2.8

i changed the gas cap on the car because the rubber was ripped, now when i drive it around the parking lot the fuel pump turns off until i open the gas cap and relieve the pressure.

i believe these cars have non vented caps. is there a vent line thats plugged?

did a search, cant find any threads with similar problems.

thanks

nosajwols

iTrader: (1)

Sounds like you have a plugged tank vent. Not sure on a TPI (others here will confirm) but there is likely a vent line between the tank and charcoal filter.

85berlinetta2.8

think if i just put some compressed air into it to blow it out?

edit: thanks for the fast response!

tnitz8787

there is a vent,it's a white plastic thing between the gas tank and where the fuel filter is.

Bad Z28

ok i had this same problem in my 92 z28 an ill tell you what i know
1st the reason it runs better when the gas cap is off is because theres a change in pressure from the fuel tank, when it is off like that it bypasses factory engine pressure for a little
2nd change your maf/ map sensor it will regulate the pressure an return it into running condition
it took me 3months of walking to work to figure this out if you get it hooked to a computer it should read code 34 i think please let me know how this goes