Gasoline from exhaust -FPR replacement

[ld50]

Hello fellow Explorer enthusiasts!

Well, as our first Gen explorers get older, things break that never broke before, sometimes causing confusion and panic. Sometimes the info is a little bit tough to dig out from the site. I would like to share some info relating to my recent failure of the "fuel pressure regulator". or "FPR"

*I figure it is important to mention that within a couple hours driving time AFTER replacing a faulty fuel pump (and replacing fuel filter), my FPR failed. I think it is reasonable to assume that replacing these items likely put more strain on the FPR, which may have spent a couple years being fed lower pressures due to a worn fuel pump and clogging filter.

What happened
Started it up, and it idled for a second, then stalled. Tried to start it again and it wouldn't start. Thought "F***" floored the gas pedal and tried again. Started up but only if you kept revving it high, sounded horrible and then there was a huge smell of gas. -So I let it stall again, cuz that's no darn good.

Started troubleshooting. Incorrectly decided it may be the IAC (Idle Air Control)
Tried cleaning it -same condition.
Replaced it -same condition.
After replacing it, a friend told me that gasoline was spraying from my tailpipe. I looked back there, and it had left a huge black stain on the grass and a cedar hedge tree back there (oopsie). So just imagine how much gas was blowing through there, TONS!

Dug a little deeper into the internets and found a tidbit suggesting pulling the vacuum hose off the bottom of the FPR to see if there was any gas in the hose.
I did that and there definitely was gas in there, a lot of gas.
Obviously this is an indication of failure!
The vacuum line runs from the FPR, tees off with another line which goes to your air filter box (or in my case is just plugged because I have a conical air filter) and also is connected to your intake manifold. (drivers side back by firewall).
-I did find it odd that they would design it this way, I did not find specific operational details of this mechanism so *does vacuum alter it's operation?, OR is it a safeguard so that failure directs fuel into the intake manifold rather than spraying it all over a hot engine? I really don't know, perhaps both apply. All we need to remember is that if it fails, it pumps fuel straight into the intake of your engine, causing it to run extremely rich!

*If vacuum does not play a role, the FPR is just a glorified pressure relief valve, dumping the over-pressure back to the gas tank.

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[ld50]

So anyway, It is very easy to replace, but a little bit expensive.
Cost me $137 Cdn, even after a great discount rate I get at the parts store.
But the last one lasted 22 years, so perhaps I will have a senior's discount next time.

So, you might wonder how to replace it? I will show you!

First, find it. It is on the passenger side of intake manifold near your oil filler cap.

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[ld50]

What tools do you need?

-8mm socket/ratchet for bolts holding the FPR to fuel rail.
I recommend a smaller ratchet size, or you may have difficulty with the forward mounting bolt, specifically. A knuckle socket might help if all you have is a larger ratchet.

-17mm wrench for undoing the fuel return line

-Channel lock pliers for moving upper rad hose out of your way.
Mine has a squeeze clamp on it. Maybe you got a hose clamp, whatever, just get the hose out of your way to make some room. I just undid it there and pushed it over till I found a place to catch it on.

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[ld50]

*Safety Note*
My truck sat a day, I knew there was no fuel pressure in the system before undoing things. Keep in mind that there could be pressure in the system, and undo things slowly.....or bleed the fuel rail by way of the schreader valve you can see further along the fuel rail (just to the left of the FPR in the pic directly below).



You just undo the fuel return line from the top, using your 17mm wrench. Then undo the two 8mm bolts that are just under the flat plate on the FPR.
Do not lose those bolts! I loosened mine then undid the last bit with my fingers. It's tricky. If you have my luck, when you drop a bolt, it's just gone man, I don't know where that stuff goes but there's gotta be a few in my engine bay somewhere.

Wiggle the FPR out, it is just has a projection which is pushed into a port and seals with an o-ring.

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[ld50]

Easy Right? You gunna let a shop do that for you? come on dude.

So, now you want to put the new one in. Just put a tiny bit of oil on the o-ring. this was mentioned in my shop manual. Didn't say what kind, I just used a bit of clean engine oil, just dipped my finger tip in some and wiped the o-ring.

Then put it back together. Ease the part with the o-ring back in the cavity, don't force it in there, it will go nicely when lined up. Don't want to ham-fist it in there and damage the o-ring.

Once you get everything tightened up, and the upper rad hose connected, you could opt to blow out the previously mentioned vacuum lines out with compressed air to ensure the gas is gone, OR do like I did and decide that another bit of fuel isn't going to matter. Don't forget to re-attach that vacuum line though.

YOU SHOULD go ahead and do an oil change now. I could not determine if there was gas in my oil by smelling the dipstick, filler cap, and even sniffing the filler opening, but the worry is that fuel can be forced into your crankcase when this occurs. -That would ruin your oil

 

[ld50]

So my entire exhaust system being thoroughly coated with fuel two days before I did the work, I figured evaporation would be on my side, but it still looked a scene from a Cheech and Chong movie for a few minutes after starting it. Or for our younger viewers; It was like backstage at a Snoop Dogg concert. Younger than that? Okay, it looked like Seth Rogen's living room.

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[ld50]

Anyway, she fired right up and eventually the smoke went away, so I took a burn into the bush to check out this abandoned hippie squatter's cabin that was supposed to be close.
Found it! was kind of neat.

 

[Number4]

Nice write up. I always liked finding these random old buildings or trailers while hunting. For some reason, though basically stripped, they still had shower curtains and they were always closed. I always imagined some drugged out crazy leaping out of there or opening them to discover a corpse. Anyway, always opened to look.

 

[the_don]

I love the work bench in the first pic!! great write up too.

 

[Styx]

Hey LD glad you got it fixed... Back in the day when I used to work for ford I did a crap load of the fuel pressure regulators for the exact thing you had happen. the diaphragm will rip inside and let the fuel flow into the intake manifold through the vacuum hose...
Good work...
btw what part of BC you in??? I'm in the east Fraser Valley...

 

[malohnes]

Great write-up and photo's.

Side note - My FPR fuel connection doesn't look like yours on my 91 XL!?! It has doesn't have a threaded fitting, but rather connection that takes a tool to undo. My replacement FPR looks like yours. I have bought a couple FPR's from different places like NAPA, Rock Auto etc and they all look the same, but I must have an odd ball rig.

Idea's for what to do? Maybe I ought to provide a pic...

 

[natenkiki2004]

Great write-up and photo's.

Side note - My FPR fuel connection doesn't look like yours on my 91 XL!?! It has doesn't have a threaded fitting, but rather connection that takes a tool to undo. My replacement FPR looks like yours. I have bought a couple FPR's from different places like NAPA, Rock Auto etc and they all look the same, but I must have an odd ball rig.

Idea's for what to do? Maybe I ought to provide a pic...

Weird, my 1991 XL has the threaded fitting as shown above. Might be that yours was a super early model and they used left-over parts or that line was replaced at some point. There was a snap-in model. Rock Auto lists it as Standard Motor Products PR44. I'm not sure what tool is required to take it apart, maybe a smaller style that the fuel filter uses?