engine light

[jamesapost]

i have a 92 explorer 4.0 4x4 and im having problems with it, i would like to know how to pull a code and where is the best place to look up the code so i can figuer out whats going on with the truck...

 

[KobeJ05]

i beleive this site has the check engine codes on here just search for them

 

[jamesapost]

i still dont know how to pull a code, is there a manual way to pull it or do i have to use a scaner?

 

[Iron Weasel]

http://www.explorerforum.com/forums/showthread.php?t=255962

 

[MrShorty]

where is the best place to look up the code so i can figuer out whats going on with the truck...

The absolute best place to look up codes and other diagnostic information is a professional grade manual. The codes will be listed according to year and engine (so, for example, the code list for you '92 won't show any of the EGR codes). Also, in addition to a 10 word definition of the code, you'll get a 10 step "pinpoint test" to help track down the specific cause of the code.

When I need this information, I go down to the local library where they have these manuals in the reference section. If you prefer an internet source for this information, I'm reasonably sure that a subscription site (like alldata) has this information (you might even check if your local library has a subscription).

 

[jamesapost]

iv just changed the altinater, and the bearings in the old one were bad, and now my gage dosn't move when i have on my lights, stero, AC, turn signals, ect! but i noticed that when the truck is not runing but is in the run postion the fuel pump cylinoid clicks off and on, and when the truck is runing and it revs and dropes rpm, the cylinoid clicks on and off. now i just replaced that part about 6 weeks ago, im going to do it again. what do you think about what i just told you, and dose any body know what the other two cylinoids next to it are, and are all 3 of them the same part # im thinking about switching all 3!

 

[MrShorty]

now i just replaced that part about 6 weeks ago, im going to do it again. what do you think about what i just told you,

While I recognize that it is possible to get a bad relay out of the box, I would be inclined to check the rest of the fuel pump solenoid coil circuit to make sure there isn't something else going on.

and dose any body know what the other two cylinoids next to it are,

They are the EEC relay and the AC WOT cutoff relay. All three relays are identical, except for color.

 

[jamesapost]

how do i check the rest of the system?

 

[MrShorty]

how do i check the rest of the system?

Which system? When it comes to these basic electrical circuits (like the fuel pump circuit), I find that the best place to start is with a wiring diagram (even the basic wiring diagrams in Chiltons are often adequate) so you can see how the circuit is supposed to work.

 

[jamesapost]

well iv changed the fuel pump relay, and its still doing the same thing, when it is running smoth i grabed every bit of wiring in the truck, sensors, conections, relays, ect. and shook it to see if it might be a short or lose conection in the system, and nothing hapned so i dont think its a wiring isue! the fuel pump is a airteck, from auto zone. its a cheep pump, and the other 2 times this hapned i just changed the pump out and this problem would go away, but it would return after a few weeks. could it be such a cheep pump that it over heats and is messing with the fuel pump relay? i am thinking about putting the bosh pump in it but i dont want to unless i know its a pump isue cus its twice the price $240.00

 

[MrShorty]

could it be such a cheep pump that it over heats and is messing with the fuel pump relay?

I wouldn't think so. The condition of the pump shouldn't have any bearing on whether or not the relay is closed. From what you've described here, I'd still be looking for something electrical. If you are absolutely certain the wiring to/from the relay is good, then the only components left to cause those symptoms are the PCM itself, the fuel pump relay, or the EEC relay. I personally am not convinced the wiring is good, but you really don't have to convince me, because I'm not there.

I think my next step would be to put a voltmeter on the fuel pump relay coil so I could see what was going on with the circuit responsible for closing the relay.

 

[jamesapost]

well you are probley right, there is something wrong with the wiring from the relay to the pump but for the life of me i cant find it. its probley in one of the spots i cant reach like by the fuel tank!!! i know its probley not the right thing to do but i buy passed the wiring, i ran a wirer from the batery to the pump with a switch on it and a 10 amp fuse and it runs perfectly now!!!

 

[MrShorty]

That should confirm that the pump itself is ok.

In bypassing the circuit like that, the main issue you'll create is that you've bypassed the inertia switch (just to the right of the transmission hump behind the carpet). The inertia switch cuts power to the fuel pump in the event of an accident to kill the engine and reduce the risk of fire. Even if you decide to bypass the original circuit, I'd recommend finding some way to not bypass the inertia switch.

 

[jamesapost]

i will try to get some info, wiring on the switch you are talking about, i know where it is and what it looks like. and how i can rewirer it so its still in the loop.

 

[jamesapost]

back to squar 1, its been a week and the truck has been runing great. but rember it has a dedicated line from the batery to the pump with a fuse and a switch. well it started doing the studering thing, could it be a bad computer? injectoers? im at a loss im about to give up and take it to the junk yard and watch them crush it!

 

[MrShorty]

I hope this doesn't come across wrong.

We started with "how to pull codes". Did you ever pull codes from the computer?

We found that the fuel pump circuit had a problem, so you bypassed it. Did you ever figure out what was really going on with the fuel pump circuit? There are any number of possibilities that bypassing the fuel pump circuit might temporarily fix or mask, but the bypass doesn't help diagnose.

I guess my advice would be to finish the diagnostic steps we started with.

I think before I took it to the junkyard for crushing, I might invest $60 for someone to diagnose it for me and see really how bad it is.