92 Exploder Fire - Rebuild

[PeteCz]

This past week I had a mishap with my 92 Explorer (XLT 4WD 4.0L). After driving for about 25 miles I stopped at a fishing shop and went inside to pickup a few items. When I came back outside (90F+) and started up the car, upon starting I heard a "whoosh" and immediately turned off the ignition and pulled the hood release (which came completely out of the dash about a foot). I opened the hood just in time to see some black smoke coming from the driver side of the engine compartment. I lowered the hood and ran inside and got a fire extinguisher. We came outside, raised the hood and put out the fire. The whole episode was probably less than 2 minutes.

I had a few folks look at it and tell me they thought it was worth trying to fix. Two repair shops in the area wanted nothing to do with it and I really don't want to take it to the dealer ($$$). It has 193k miles, but the body is in great shape and ran very well up 'til now. It has a new transmission (less than 15k miles on it), new tires, new battery, new starter and other stuff. If I can get it running for around $300 or less I want to do it, otherwise I'll have to part with it. This is my 4th 90ish explorer and I really want to hang on to it.

I'm not a mechanical expert but have some basic skills and would like to give this a go, if its worth doing. I am putting together a list of items I will need to purchase/replace. I have been trying to use my Haynes repair manual and AllDataDIY.com, but am having trouble identifying some parts. It appears that the fire was confined to a pretty small area, but the heat melted a few other components. Here is what I already have figured out:

Replace:
- Air Charge Temp Sensor and Coupling (possibly where the fire started)
- Idle Air Control Valve and Connector (I had been having a rough idle condition anyway)
- Accelerator Cable (throttle cable)
- A few Vacuum Hoses
- A few Vacuum Caps
- A few items that I can't identify (pictures provided)

So what I need is:
1) some help identifying what some of the parts are, and
2) some advice on whether this looks worth doing.

Some Pics:
This is the entire area

Here is a closeup of the main area.
- The hose from the Master Cylinder should be replaced
- The hose "G" should be replaced and connected to "E"
- There should be a hose from "F" to "B" - What is the "F" Connector?
- "A", "C" and "D" get capped?
- The hose "H" should be replaced (from the Intake to the Head)
- The Air Charge Temp sensor and Coupler should be replaced (partially inserted in the pic)
- The Accelerator Cale should be replaced
- The Idle Air Control Valve and Coupler should be replaced (not in picture)

On the other side of the engine a few parts melted that need to be replaced, but I can't identify:
- What is "A"? it has a pinhole in it and has deformed in shape
- In the Circle "B" is a part that broke off once the hose (wire) cooled
- Part B is connected somehow at "C", a point farther over on the passenger side of the engine and an unknown spot. Any ideas?
- Is "B" a vacuum connector of some sort or electrical?
- What is "D" and should it be replaced?

Any and all help is greatly, greatly appreciated!

Also: I know that this doesn't solve the real problem: why did this happen in the first place. But If I can get it up and running then I will try to determine what caused it...

PeteCz

 

[Masterd]

I cant believe nobody has replied to this yet.

Id run by the Ford website and run your VIN # through the cruise control recall thing, maybe that could have started your fire.

 

[Maniak]

It actually doesn't look too bad.. Grab a wireharness from a junk yard (you need one from the same year.. 1991 has different connectors and 1993/1994 I think have egr and cam sensor which you don't have).

The vacuum lines go to the following places..
Master Cylinder
Cruise control
Transmission (F looks like the hard line from the transmission in your pic)
Fuel pressure regulator
Blend door etc.. (it goes to the vacuum canister and t's off to the air box which is A,B & C on your pic)

The other vacuum ports on the octopus are capped off.

H looks your your PCV.. PCV in valve cover and hose to plenum.

I'll have to look at the X to see what D is, its not standing out from the pic.

 

[BrooklynBay]

Welcome to this forum! Contact KBabiak. He's one of this site's vendors, and has many wiring harnesses. Be glad that you put the fire out in time, and it didn't look like this:

 

[PeteCz]

New Problem - big gas leak...

Hey Guys thanks for the replies...

I went to a "used parts emporium" and have started rebuilding. I replaced:
- the main electrical harness
- vacuum canister
- harnesses for the idle air control valve and Temp Charge Sensor
- Washer fluid lines
- vac lines for the Master Cylinder, Cruise control?, Transmission and Vac canister
- capped the other ports
- throttle cable and hood release cable
- A length of 3/8 rubber vac line for the PCV hose (is that ok?)

Is the cruise control the canister looking thing that has a cable that runs in tandem with the throttle cable at the throttle body? If so, the hose from G was spliced and hooked up to port E (in the pic above), but I'm worried that I should have replaced the entire hose. It's metallic inside and I'm not sure how well the splice will hold. Thoughts?

Anyhow I got it all together and actually started it up. It was running/idling well and I hopped out to look at it and noticed a LOT of gasoline spewing from near the fuel supply line, so I quickly shut it down and let it cool down. Thinking it was the fuel supply line I removed the upper intake manifold to get a better look. When I turn the key over to build the fuel pressure I see gas streaming from what looks like the melted end of a plastic vac tub that is only connected to the FPR. I'm assuming that this should have been connected to the Vac port as well, but I will need to splice it and add some length. Any good ideas on how to splice the small plastic vac lines? They look awfully flimsy. I have some left over plastic lines from the vac canister, but they are not the exact same I.D. (the additional line I have is a bit smaller inside) does that matter? I could use some 5/32 rubber tubing and fit both cut ends into the tubing for about 2-3". Would than be adequate?

I also just noticed that there is another vac line in the housing for the FPR vac line that runs back to the air filter cover. Does that get hooked to the vac port tree as well? I didn't see it mentioned anywhere else.

 

[Maniak]

Hey Guys thanks for the replies...

I went to a "used parts emporium" and have started rebuilding. I replaced:
- the main electrical harness
- vacuum canister
- harnesses for the idle air control valve and Temp Charge Sensor
- Washer fluid lines
- vac lines for the Master Cylinder, Cruise control?, Transmission and Vac canister
- capped the other ports
- throttle cable and hood release cable
- A length of 3/8 rubber vac line for the PCV hose (is that ok?)

Is the cruise control the canister looking thing that has a cable that runs in tandem with the throttle cable at the throttle body? If so, the hose from G was spliced and hooked up to port E (in the pic above), but I'm worried that I should have replaced the entire hose. It's metallic inside and I'm not sure how well the splice will hold. Thoughts?

Anyhow I got it all together and actually started it up. It was running/idling well and I hopped out to look at it and noticed a LOT of gasoline spewing from near the fuel supply line, so I quickly shut it down and let it cool down. Thinking it was the fuel supply line I removed the upper intake manifold to get a better look. When I turn the key over to build the fuel pressure I see gas streaming from what looks like the melted end of a plastic vac tub that is only connected to the FPR. I'm assuming that this should have been connected to the Vac port as well, but I will need to splice it and add some length. Any good ideas on how to splice the small plastic vac lines? They look awfully flimsy. I have some left over plastic lines from the vac canister, but they are not the exact same I.D. (the additional line I have is a bit smaller inside) does that matter? I could use some 5/32 rubber tubing and fit both cut ends into the tubing for about 2-3". Would than be adequate?

I also just noticed that there is another vac line in the housing for the FPR vac line that runs back to the air filter cover. Does that get hooked to the vac port tree as well? I didn't see it mentioned anywhere else.

The vacuum sources aren't picky. The Brake booster and the cruise both need to be connected, and I personally run seperate lines, but I've seen people share a line (using a T). The difference is that if you loose vacuum you loose brakes and cruise if you T the line. If you use single lines you only loose vacuum for the brakes when the brake line comes off/breaks. As long as you get a vacuum line between the device and the vacuum port (octopus) it doesn't matter which one you connect to, other than the port be the same size as the hose.

As for the fuel leak.. You actually have a bad Fuel Pressure Regulator. Fuel should not come out of that line. Thats one of the tests when the vehicle is running rich, check that vacuum line. If you have fuel in there, replace the Fuel Pressure regulator.

As for the other vacuum lines, When we rebuild the motor on our '92 I used all new vacuum lines. I used very little hard lines (factory lines). 15k miles and no problems, and I don't expect any either.

Unless your lines are oil soaked (soft) the engine doesn't produce enough vacuum to collapse them.

k.. enough rambling..

~Mark

 

[PeteCz]

Thanks Mark!

After putting it all back together I tried running it and thankfully (?) I had not tightened the supply fuel line all the way and had a leak at the supply connection so I took it all apart and noticed gas also (still) coming from the vac tube into the manifold. Will that cause any damage? My guess is that maybe that was what caused the fire in the first place. At least thats what I hope. It seems like the fire was at the vac port. So if gas was being sent there (when it shouldn't be) then excess heat of the engine and the outdoor temp may have been enough to start the fire...just a guess.

Looks like I'll go get an fpr and try it again...........

 

[Maniak]

I've never heard of a bad FPR causing a fire but its possible. Assuming there is no vacuum leak there (where gas can come out) the gas in that vacuum line would go into the upper intake and make it run rich. Thats the only symptom I've heard of from a FPR that has gone bad that way.

If you had a leak there (vacuum), the gas could have dripped onto the upper intake and started a fire. The other posibility is that recall someone already mentioned about a short at the cruise control switch (brake booster). The fix was a fuse so if you got a short, it wouldn't burn wires.

~Mark

 

[PeteCz]

So Far...So Good!

I replaced the FPR and reinstalled the Upper Intake Manifold (Do the folks that design cars ever work on them?) after much more effort than it should have taken, and got everything else hooked up. Crossed my fingers and started it up.

The engine sputtered at first but then found its groove and sounds better than it did in the 4 years I've owned it. The A/C works, the Wipers and Fluid work, no CEL and no gas or fluid leaks. I had some other things to do, so I never got to drive it but 8-10 mins of very smooth idling and so far so good.

However, I'm worried that there may be a problem with the brakes. I stepped on the brake pedal and it seemed softer than before and never offered much resistance. As you can see from the very right hand side of the first picture above that the oil fill cap was melted a bit. It seems to still lock down when its threaded properly, but could an air leak in the cap cause the brakes to give out? Is it possible that I just need more fluid? I'll test them tomorrow and see if they have been damaged.

The only other cause for concern is the wiring harness. It was not an exact match and there is one port that has nowhere to plug it into. Not sure if it will be a problem down the road...

But for now, it looks like I'm headed out of the woods...

Thanks for your help!

 

[Maniak]

If you got a 1993/94 wire harness you have the cam sensor or possible EGR wires, but if it "needed it", you would have a CEL. The PCM must be getting all the info it needs if you didn't get the CEL, but run a code reader on it so it can do a self test just to be sure..

As for the brakes, even if the cap was letting air in, the brakes would work fine as brakes don't get air in the lines as long as the lines stay covered by fluid.

If the master cylinder got hot enough maybe it hurt the piston in there. Also check the brake lines, make sure they didn't melt and get soft.

~Mark