I have searched for hours to get ideas. Nothing really new popped up.

I get a strong gas smell if I press on the gas pedal more than normal - I think. So what I am thinking, is that the fuel pressure is rising due to vacuum dropping at regulator and causing an oring to leak along the rail. I am trying not to over think this. Sound reasonable? I am going to try to get the pressure up tomorrow in the driveway since I can't ride under the hood going down the road.

I can go a day or three without the gas smell and then it pops back up. I rarely take off fast except to get into traffic so its not often. Never go over 4000 rpm and then maybe only a couple times a year - usually 3500 max. Does not matter at all how much fuel is in tank.

If it leaked all the time it would be easier to find.

I have looked at everything closely with it running and i see nothing. And I am sticking my head down as close as I can.

89 TPI 350 from an 89 IROC. Rebuilt with 20k, maintained about as good as is possible. All new parts where ever I could think of buying anything. All stock but for small cam and flat tops. ALL emissions equip is installed and working (to the best of my knowledge).

I used to think it was the charcoal canister but I went through that with a fine tooth comb. All new lines, etc. Seems good. The canister and purge valves etc is the only things I have not changed out under the hood.

Thanks for your thoughts. I know this comes up a lot, I just couldn't find anything that fit

 

All you have to do to simulate the "rising pressure" deal, is disconnect the vacuum line to the regulator. The FP will go to the same level just sitting there idling, as if you had floored it on a xway ramp.

The theory doesn't sound "reasonable" to me; that is, the idea that going from 38 psi to 43 psi or some similar change, is going to spring a leak, which then heals when the pressure drops back that little bit. In any case, if an O-ring was leaking, you'd be able to see fuel at that spot: no fuel, no leak.

I'd be more inclined to suspect that you have injectors that are too large and/or your tune is off, and there's too much fuel getting fed to the motor at heavy throttle.

 

Running rich !

 

EDIT: Found it. Big leak on the crossover tube between the rails. I can't believe it didn't leak all the time the way it was coming out. Big pool of gas on the intake in a minute or two.

I did take the vac line off but don't know if that had anything to do with it deciding to leak. Fire waiting to happen.

I'll change all o-rings and then check fuel pressure with vac connected and disconnected.

 

Sometimes all it takes is a quick look. Good thing you found it; big fuel leaks can get REAL ugly REAL fast. Sounds also like the "press the gas pedal" thing was a red herring.

 

Yes, I was not sure of the engine rpm raising, but the dang thing was elusive as hell. I had looked 10 times at least without seeing ANY leak. Then bam! It was not a small leak, it filled up the intake and was FLOWING to the rear. Fixing an awning leak now waiting on the seals to come in.