92 Explorer stalling then will not restart

zzrich · #1 (**permalink**) 04-30-2009, 05:56 PM

I buddy has a 92 explorer that runs fine til you get about a mile or so away from home then dies and will not restart.

Today I pulled some codes : EEC IV

62 : this came up because of the 4th gear solenoid is unpluged (known problem)

66 : Maf/Vaf low bad maf/vaf leak in hose from maf to engine. (cleaned the maf, plugged small crack in intake hose)

95 : Fuel Pump fuel pump monitor has seen a fault in the pumps or circuit (I have not addressed this problem yet)

Sounds to me like the fuel pump is getting weak, anybody else ?

mrshorty · #2 (**permalink**) 04-30-2009, 06:06 PM

1st thought: double check those codes (or the year) '91 Explorers output 2 digit codes, '92+ Explorers output 3 digit codes (unless you got a '91 computer in your '92). Just want to make sure we are reading the codes right. It also often helps to distinguish between KOEO (1st set output during the KOEO test before separator pulse) and CM codes (after separator pulse).

Any sign of life from the fuel pump? Have you checked fuel pressure? If the fuel pump isn't running, be sure to check the wiring/relays before you blame the pump itself.

zzrich · #3 (**permalink**) 04-30-2009, 06:31 PM

Quote:

Originally Posted by mrshorty

1st thought: double check those codes (or the year) '91 Explorers output 2 digit codes, '92+ Explorers output 3 digit codes (unless you got a '91 computer in your '92). Just want to make sure we are reading the codes right. It also often helps to distinguish between KOEO (1st set output during the KOEO test before separator pulse) and CM codes (after separator pulse).

Any sign of life from the fuel pump? Have you checked fuel pressure? If the fuel pump isn't running, be sure to check the wiring/relays before you blame the pump itself.

Thanks. Yes it is outputing 2 digit codes. My tester has both a light and an audable signal when the codes are read. Maybe someone swapped the ecm ? The fuel pump kicks on right when you turn thee key on. I havent checked fuel pressure yet (dont have a gauge).

The truck will sit and purr like a kitten in the driveway. But when you get out on the highway it just dies suddenly. Doesnt loose electrical, lights, gauges and all work turns over but wont start next day starts up like nothing ever happened.

zzrich · #4 (**permalink**) 05-01-2009, 01:25 PM

A little update here. The fuel pump seems very very loud (you can hear it over the motor runing). The owner says it just started making the loud humming noise.

mrshorty · #5 (**permalink**) 05-01-2009, 06:30 PM

Change in the sound of the fuel pump suggest something with fuel delivery. I'd still start by putting a fuel pressure gauge on it.

zzrich · #6 (**permalink**) 05-01-2009, 06:45 PM

Quote:

Originally Posted by mrshorty

Change in the sound of the fuel pump suggest something with fuel delivery. I'd still start by putting a fuel pressure gauge on it.

Sounds right on. Now I just have to talk my cheap buddy into buying a pressure gauge !

What brand and model should I get ?

mrshorty · #7 (**permalink**) 05-01-2009, 11:36 PM

I've liked the Actron fuel pressure gauge I got (~$40 from autozone or pep-boys, maybe other similar places).

marragtop · #8 (**permalink**) 05-02-2009, 06:52 AM

If you do have a fuel pressure problem, start by changing the fuel filter and then regulator. The fuel pump is the last thing you want to do. Also, during the no start situation, do you hear the fuel pump prime when turning the key to the ON position? If not, replace the fuel pump relay.

zzrich · #9 (**permalink**) 05-02-2009, 02:00 PM

I havent been in the truck when it stalled. One thing my neighbor told was the last time he had it out the truck opened to full throttle on its own !

He had a hell of a time getting it stopped I guess. I m thinking it was a pinched throttle cable or maybe something else ?

I try changing the other parts first (filter and regulator). I know that replacing the pump is a real pita ! Thanks guys for the help so far !

zzrich · #10 (**permalink**) 10-30-2009, 06:55 PM

Okay. Now the beast is mine !!!! Traded a camper shell for it. (thats how we do it the trailer park !!). Ive been driving it on short trips. No problem. Then today I went down to the trash can with it and shut it off. I t wouldnt restart. The pump also would not prime when key was turned on. I waited a few minutes cursed it out, then it started no problem. Maybe marragtop has the best way to go ?

marragtop · #11 (**permalink**) 10-30-2009, 08:37 PM

When you turn the key to ON, did the CEL come on? If not, it could be the PCM relay. If the CEL does come on, then I'd replace the fuel pump relay. Both relays are in the power distribution box under the hood.

zzrich · #12 (**permalink**) 10-30-2009, 10:55 PM

Quote:

Originally Posted by marragtop

When you turn the key to ON, did the CEL come on? If not, it could be the PCM relay. If the CEL does come on, then I'd replace the fuel pump relay. Both relays are in the power distribution box under the hood.

Hi. I am not a repair tech, I dont know what CEL is (im sure its something I can understand though !) But having the relays in an easy location is nice ! Thanks marragtop for your help so far. We may need to drive this thing for a couple of months to get us by.

mrshorty · #13 (**permalink**) 10-30-2009, 11:18 PM

CEL=Check Engine Light. It's supposed to come one when you turn the key on but don't start the engine as an indication that the PCM is getting power. Since the PCM is responsible for grounding the fuel pump relay to run the fuel pump, It's a good quick check on no starts to make sure the PCM is getting power.

zzrich · #14 (**permalink**) 10-31-2009, 12:33 AM

thanks mr shorty. I knew it had to be something simple ! I will go out right now with a coldy and check it out !

zzrich · #15 (**permalink**) 10-31-2009, 01:02 AM

Yep the CEL comes on koeo . But it started no problem. Next time it fails to start, ill turn it off and back into koeo to see if the CEL lights up. much obliged ! Damn I wish for the early days when all you had to was gas n' go !