1993 Explorer Gas leak Cant Find it

[airfreddy]

Hello Everyone.

I have a 1993 Ford Explorer xlt, It has a huge gas leak but only when it is cold out.. probably mid 40's once it warms up there is no leak. I took it to the shop this morning and they could not find anything. It was leaking when I left but stopped by the time I got to the shop.

The mechanic thought it was an injector gasket but they pressure tested everything and found nothing. They wanted to leave it over night and start it first thing in the morning but I decided to do the same...

Any ideas. i comes out pretty good under the engine just behind the front tires. I am thinking it may be the purge valve in the emissions loop.

 

[arco777]

Welcome to the forum!

The evap system should only be running fuel vapors and not liquid fuel. Since the steel braided fuel lines are pretty stout, unless one chafed through on something (which wouldn't go away when warm) I'd look at the injector O-rings. You should be able to see a pool of gas around the base of them if they're leaking onto the lower intake manifold.

 

[airfreddy]

Well I let it sit all night and started it up this morning and fuel was poring out of that one injector. It stops after the engine is running for a few minutes

Thanks

 

[arco777]

Try wiggling the injector around and hopefully it will seat better. If it is leaking around the base you may be able to push it downwards a bit to seat deeper.

You're probably going to need to replace the o-rings on that injector. Good time to replace them all, as the o-rings themselves are cheap. Finding new pintle caps is a little tougher but they are available. Injector rebuild parts for 87-93 Mustangs interchange. Your old pintle caps will probably break upon removal. You'll also need intake manifold gaskets (upper only) and an E7 torx socket. Nothing expensive or challenging. You can also replace the injector screens while you're in there. There are tutorials on the job documented on this forum.

 

[airfreddy]

Well Guys:

I pulled everything apart and when I was taking everything apart I took the fuel pressure regulator off the fuel rail. It came right off and I just wondered if that is where the leak was. It is difficult to see everything when it is together so it was tough to see where exactly the leak was..

So rebuilt all of the injectors with new o rings and got everything back together.. Runs fine but I looked at it closely and that is where it was leaking. The gasket on the fuel pressure regulator is failing ..

So back to auto zone in the morning. Looks like I can't find just the gasket for it.. I think I have to buy the entire unit.

 

[arco777]

That's interesting. First I have heard of a regulator leaking.

You should be able to find a replacement o-ring even if it is not listed in catalogs. Just will take research. If you can get your old o-ring off with a hook or pick, you should be able to measure the required inner and outer diameters. You could cross reference with manufacturer charts, or buy an assortment and try whatever one works best. I say all this because I'm on my original regulator (and its o-ring) at 197k and the replacement is too expensive for me to justify buying when mine still works fine.