Well, I have been gathering information on what is a new problem with my truck. It is a 1995 F150 4x4 with the 302 V8 and automatic tranny. Anyway, ever since the weather has started getting nice over the course of the last week, I have been smelling a raw, unburnt fuel smell. Can smell it when driving, but is especially strong after coming to a stop and turning the truck off. Have been unable to notice an leaks in the fuel system. Also, on ocassion, at idle and in gear, the engine will kind of hesitate or drop idle just for a minute, but it does not show on the tach.

Anyway, I have had a couple of suggestions that it could be the "purge valve". My questions are: what is the purge valve, where is it located, and how hard to replace.

By the way, the truck does have dual tanks.

Any and all help would be appreciated.

Thanks.

 

I just replaced my tank, was smellin fuel when I stopped, when it started it wasn't visible, but sure could smell it. Got worse over time til I saw. Replacin it is a pain, hope its a purge valve, gotta be easier to replace than a tank

 

Hi Eric Welcome!

Im just guessing...but check the PCV valve. That its sucking ok, not sticking or plugged. Usually plugs into top of valve covers.

Also another long shot...but if your engine has the charcoal (fume) cannister mounted in engine bay...check line plugged in..not broken, leaking etc.

Maybe it'll be simple fix?

Good luck...OT

btw...double ck. to be sure it is not a fuel leak. When you smell it, pull over/stop..start looking right away. Engine fires happen fast.

 

The purge valve is a valve the controls the fresh air inlet to the charcoal canister. When the purge valve opens fresh air goes in a purges out the fuel vapor from the canister, the vapor is sucked into the engine and burned. They are easy to replace, just 1 or 2 screws an electrical connector and some vacuum lines. I don't remember it's exact location offhand, should be close, or even attached to the canister.

-Jon

 

I think its right next to the charcoal canister on the passenger side, just below the battery on the side of the fender

 

That's how I found my tank leak too. I could smell it but didn't get a leak until one day I topped off and parked on the driveway at an angle. Even then it was just a drip.

 

if you fill your tank full up to the brim, and it's a warm day, and the fuel expands, and the pressure relief valve in your gas cap doesn't release, liquid fuel can end up in the evaporative control plumbing and cause venting problems and the stink of gas. if your charcoal canister is saturated and needs replacing, replace the gas cap with a new oem cap at the same time, and don't top off when you fill up

 

I never realized there was a pressure relief valve in the cap:o
Do they go bad often? My truck is a 92' and the caps neve been replaced.