93 Explorer fuel problem I think help ???

[bruce119]

I am a new member and did say hello in the new member forum but I got a BIG problem to try and solve. Thanks in advance

So my problem rite now is I think a fuel problem. The fuel gage stopped working about 2 years ago. No problem I use the miles and fuel up every 200 miles no problem. Yesterday the truck was going down the road and the truck died wile driving at about 40mph. My first thought was I ran out of gas but I only had just over a 100 miles on that tank. So I was lucky to coast into a gas station and put $10.00 in. The truck started I thought problem solved I must have forgot to reset the mileage or something. So I drive the 2 miles home with out a problem. Now this morning I start up and go just over a mile truck dies again. I pull off in a lot and try to start and the trucks start rite up. I pull back on the road and it dies again in about 100 feet. I am able to cast into a restaurant have breakfast. There about 30 minutes start the truck to head home go about 2 miles and it dies again just short from home. I pull off and try to start rite away truck starts and this time I only go about 100 feet and dies again I am able to coast to my driveway.

So I am trying to figure the problem. It sounds fuel related to me and the longer the truck sets after it dies the longer it runs. Any thoughts I am trying to get a real good idea before going to the shop. I am a back yard mechanic but it's Florida and HOT and I'm getting a little old. I am thinking best case a fuel filter and maybe worse fuel pump.

Anyone with experience to these symptoms.

Thanks
Bruce from Florida

 

[backfrmcolorado]

Yeah ive had about the same problem with my 94. It may just be bad gas or clogged fuel filter. It may also be a realy problem. I know when i replaced my fuel pump the screen was caked with gunk so that may be a problem too. Good luck on the fix!!!

 

[MrShorty]

Fuel system is probably where I'd start. I don't know how much diagnosis you are wanting to do, but here's where I'd start.

As intermittent as this is, it really seems like something electrical. So I'd start with the fuel pump circuit. Get a wiring diagram and locate the important components (fuse, relay, inertia switch, pump connector behind the tank). Next time it stalls/won't start, see if the pump is getting power.

 

[backfrmcolorado]

Check the shut off switch, it may be bad too. Guessing game now with wireing.

 

[bruce119]

Could it be fuel pressure problem perhaps caused by a clogged filter. It seems logical to me though I don't really know. It so far is a steady problem with a steady pattern. The longer it sits the longer it runs when it dies and I restart it only runs a short distance if it sits longer it will run longer. I am just theorizing maybe as it sits fuel is seaming through the filter allowing for more pressure. If it is dying due to low pressure then when I restart rite away the pressure is already low and the reason it dies sooner Rather then when it sits for a 1/2 hr I can go a mile before it dies.

I guess I will take it to the shop. I figure they will probably put a fuel pump in and a filter I guess that would be around $400.00. Does that sound close May gage does not work also is that part of the fuel pump or completely separate I know it is in the tank also. It's just too hot now and I don't have anywhere to get out of the heat.

thanks

 

[backfrmcolorado]

What you are theorizing sounds like it may be the problem. If yur gage isnt woking its most likely on the sending unit in the tank. Its really not that hard to drop the tank and put a new sending unit in. Its about $140.00 for the complete sending unit with new pump and like $5.00 for lock ring. A new fuel filter is around $10.00-$12.00. Both are not very hard to change. You could save a lot of money doing it this way.

You may also want to check fuel pressure before you start this process.

 

[MrShorty]

Could it be fuel pressure problem perhaps caused by a clogged filter.

I'm sure it could be, though I would still be more inclined to think an electrical problem in the fuel pump circuit rather than a clogged filter. In any case, it wouldn't be overly difficult to put a fuel pressure gauge on it along with a multimeter and see what is going on (does the pressure drop off before the pump shuts off or does the pump shut off before the pressure drops off).

I guess I will take it to the shop. I figure they will probably put a fuel pump in and a filter I guess that would be around $400.00.

$400 parts and labor is probably not too far off. Before I paid someone to replace the pump (arguably the most expensive and labor intensive part of the fuel system to replace), I'd pay them to diagnose it first. It would irritate me to pay $400 for a new fuel pump to find out that I really only needed $40 (diagnosis, parts, and labor) to replace a relay.

 

[bruce119]

Yeah ive had about the same problem with my 94. It may just be bad gas or clogged fuel filter. It may also be a realy problem. I know when i replaced my fuel pump the screen was caked with gunk so that may be a problem too. Good luck on the fix!!!

Well I was going to give a follow up with a all is good. I took the truck into a local garage with high recommendations from the neighbors. Nice guy an old timer looks like an old school garage. Anyway he put a new filter on only cost $25.00. I think that was fair I would have done it myself but it is way too hot. I don't have any shade and crawling under the truck is not fun for me anymore.

So I drove it today over 25 miles around town made quite a few stops no problems.

BUT this afternoon when I went to pick my wife up it started again. Stalled rite away when I backed out the driveway started rite up went a little farther stalled again. Seems like a little different symptoms I can now feel it losing power and then stalling. So I call the shop and he say the pump and after thinking about it I think I am in agreement. As said above by backfrmcolorado a clogged screen in the tank on the pump makes sense. I mentioned this to the mechanic he said it had a sock but same difference if the sock is clogged.

My theory now the pump was clogged to begin with probably for a long time. I have been missing a fuel cap for about 4 months now (I know). Anyway the filter was clogged he said it was real bad. Now with the new filter in I am thinking the pressure may have picked up a bit and the filter on the pump in the tank was just on the edge of keeping up with the flow rate that now with the less restricted flow with the new filter the pump's filter picked up more gunk so that it clogged in the tank and restricted the pressure again to cause problems. I know some of you said electrical but this just does not feel electrical to me.

If anyone thinks my theory is close or I don't have a clew please chime on in. I am waiting for him to give me an estimate (I'm guessing around $400) and he's trying to find time to work on it. My gas gage don't work either I asked about it if it was part of the pump he said it was another module and wasn't cheap. So I can do with out a gage for now. I will be sure to have him flush the tank real well when he has it out.

Well thanks for the replies I will keep you guys informed. I got a lot more problems to talk about but latter got to get back on the road first.

Thanks
Bruce from Florida

 

[MrShorty]

A filter that is clogged bad enough to cause the engine to stumble/stall/not start like that would cause the pressure to drop off, which should be pretty easy to see with a fuel pressure gauge. In some non-scientific tinkering I once did with my '92, it seems that the minimum pressure necessary to run "smooth" is between 20 and 25 psi. A normal system shouldn't drop much below 30 psi (and that drop is only in response to and increase in engine vacuum. If the system is working correctly, the pressure should never drop much below 40 with the vacuum line disconnected from the FPR). It shouldn't take much effort to see if the fuel pump isn't delivering like it should.

 

[TestPoint]

Found this post through a search for 'fuel pressure'. Seems like 41 psi is common. What is the specification for fuel pressure?

 

[MrShorty]

35-45 psi is the specification for the continuously circulating fuel system like the 1st gens use. This design was used for the early 2nd gens, but somewhere along the way, Ford went to a returnless design which, I believe though I'm not sure (I don't pay too much attention to 2nd gen stuff), is supposed to operate around 60 psi. I'm almost certain someone posted information on troubleshooting the returnless system (in its own thread or in the fuel pressure mini-diary).

 

[ranger7ltr]

Fuel specs...

Return type fuel system 30-40 psi, dependent on engine vacuum...Regulator mounted on fuel rail with fuel return line to tank...
Returnless fuel system 65-73 psi, continuous pressure on system...Regulator in fuel tank mounted on sending unit...No return fuel line to tank...Started in model year 1999...