fuel smell issue

[Desperado]

on my 87 fox i have notice lately that when i get on it it is fine but when i let off the gas i can smell a strong gas smell? was doing it with the 19 lbs injectors so i upgraded mass air and to 24 lbs injectors. any clue? want to solve this issue quickly. was running fine up till about 3 days ago. still runs great just has the fuel smell. sometimes it does it just comming to a stop from driving. have looked and can't see any fuel leaks from the tank to the injectors.

car specs.

87 stock short block and cam
mass air conversion
24 lbs injectors
equal length shorties
off road h-pipe
gt40 heads
1.7 roller rockers
frnder well cold air.
70mm tb
perfessional products typhoon intake
all smog stuff is still hooked up.

 

[18mustangs]

on my 87 fox i have notice lately that when i get on it it is fine but when i let off the gas i can smell a strong gas smell? was doing it with the 19 lbs injectors so i upgraded mass air and to 24 lbs injectors. any clue? want to solve this issue quickly. was running fine up till about 3 days ago. still runs great just has the fuel smell. sometimes it does it just comming to a stop from driving. have looked and can't see any fuel leaks from the tank to the injectors.

car specs.

87 stock short block and cam
mass air conversion
24 lbs injectors
equal length shorties
off road h-pipe
gt40 heads
1.7 roller rockers
frnder well cold air.
70mm tb
perfessional products typhoon intake
all smog stuff is still hooked up.

The o\r h-pipe has a lot to do with the smell. I recently put a high flow catted pipe on in place of my o\r h-pipe to get my car inspected and my '93 octane cologne went away! You should also check the hoses leading from the vapor canister to make sure they're not cracked or vulcanized.
Tim

 

[HISSIN50]

I am with Tim. My first thought was that when you let off the throttle and decel from high RPM, your manifold vac is through the roof, and perhaps you have fuel getting into the vac system (CC, FPR, etc).

Good luck.

 

[Desperado]

will check those. the fuel pressure seems to be good. 39 with vaccum line off and 35 with it on. will check canister. the fpr is good thouh. no gas in line or eratic pressure.

 

[89white50]

my motor is mostly stock right now, which is why im guessing i dont have the smell problem. But i NEVER smell gas with my offroad H, just me though. weird. I like HISSINs idea though. makes sense

 

[Dbeck002]

I have a similar setup, offroad H, aftermarket heads, afpr etc...

i smell lots of gas fumes at idle too, its the offroad H doing it.

 

[Desperado]

well it was fine for the last 5 months. just started doing this. so i don't think the o/r ppe is to blame.


could it be a leaky injector?
o2 sensor?
emissions stuff malfunction?

how to check the carbon canister? gas mileage has also gone down. now only get 125 miles to a tank. need fix asap so please keep suggestions comming

 

[HISSIN50]

The cannister is in the pass side front of the engine bay. Check it for cracks or wetness. CHeck the FPR vac line for fuel in it (suggesting a bad FPR diaphram). A general once over might be revealing.

Yanking codes is always good since you dont have a functional CEL.

Good luck.