Gas leak

[Bmwz389]

I have a 92 XLT 2WD

I have a strange problem that is really annoying me now. From what I thought was the purge valve broken, is actually a leak at the FPR. After replacing the Purge Valve, that's when the leak started showing. It weird, because when I pulled the FPR out of the fuel rail, the o-ring looked cracked and a little torn, so I went searching around to different chops and got a new o-ring off a new FPR. The o-ring was thinner but still fit snug. The thing is, when I put it back on the fuel rail, it doesn't leak.it takes a good 7 hours for the leak to come back. Its leaking enough to puddle every dip on the lower intake manifold. My only two guesses at this point is that the new o-ring, coming from an aftermarket FPR, stretches due to heat causing the leak, or I have a tiny crack in my fuel rail, expanding after it heats up.

Any guesses?

Thanks again,

Brandon

 

[Bmwz389]

Anyone? Anything? I'm kind of sitting in the water here. Kinda need my truck....

 

[joefnh]

More than likely the o-ring is the issue. I would agree that the thinner o-ring is borderline sealing the fuel rail. After heating not only with the metal expand slighlty, but as you mentioned the characteristics of the o-ring could change. I would find the correct o-ring and see if that solves the problem.

Good Luck

--Joe

 

[Bmwz389]

K thats what I figured, just wanted a seconds opinion. I called ford and they didn't have one, I lost the old one and the new is all i have left. I remember the characteristics of the old ring so I'll have to look around.

Thanks again!

Brandon

 

[schmidlkofer]

go look at places that they sell parts for compressed air...i have o rings of all sizes for paintballguns...

 

[Bmwz389]

Ok so finally I said crew it and gave in. I bought a new aftermarket FPR, so that I wouldn't have to search everywhere for a stupid piece of rubber. Every since then I've had a random slow start and I'm going insane. Sometimes it takes normal 2-3 seconds to start. Other times it take 7-10 seconds to start.

My gut tells me it's a pressure leak, since I don't see or smell gas anymore.

Any ideas??

 

[MrShorty]

My gut tells me it's a pressure leak, since I don't see or smell gas anymore.

The first thing I would do then would be to put a fuel pressure gauge on it and verify that fuel pressure isn't coming up as it should when starting.

 

[Bmwz389]

Yeah I should have mentioned as well that it's almost always when it sits for a while. That's what originally made me believe it was a pressure leak...Maybe I can rent one from Autozone. If not I can just buy one, they are only like what 30 bucks or something?