Martin082514

Okay thank you to everyone who has helped me in my RPM problem in my 1987 Corvette another question now and I just noticed it I ran my Corvette for a while down the streets and came home parked it and like 4hours later I decided to open the cap in the gasoline tank as if I were putting in gas and when I opened it it did a type of breathing thing where as if the tank was blowing air out when I opened as if there was air pressure stuck in there and finally blew it all out when I opened it is it normal for it to do that if not what could it be I was thinking of probably drilling a small hole on the gas cap to let it breath but I don't know I'm not a mechanic I'm just trying to do all the fixing on my dream car myself please help and thank you all.

JimLentz

I know my 1992 Corvette does the same thing. Do not drill a hole in the gas cap as it is supposed to be a sealed system.

kael

This is normal, would actually be a concern if it never happened.

aklim

I wouldn't drill a hole in the fuel cap if it were me. Bad things might happen if a spark were nearby.

C409

..... Run a diagnostic check on the vapor recovery system ... charcoal canister in the left front fenderwell ... on my '87 the vent line from the tank to the canister was clogged ... blow compressed air from the tank end forward .....