Completely baffled...Fuel system issues, I think!

[tacker62]

Hi all,
I am hoping to find some help. i bought a 94 Explorer 4.0 with 4 wheel drive but the 4 wheel drive is out. The problem i am having is some where in the fuel system or O2 system.

When I bought it the X was a little doggy so got oil change and seemed better. A few days later we got 20 inches of snow and drove through unplowed road and it died. Towed it home and did the computer test. It said it was bad EGR and bad DPFE. I changed both as well as the fuel filter. In the process of changing the EGR the EGR tube broke and it took me a week to get a replacement and fix it. After replacing the broken tube started it and it would barely idle and no power. Did the computer check again and it said both O2 sensors were throwing codes.

I cleaned the MAF and cleared the computer. It ran for about 10 minutes and then dogged again and still low idle and no power. I took off the gas cap and it ran well for another 10 minutes and once again it is dogging out. Very low idle with missing, no power when put in gear. Fuel pump engages but not sure of anything. It is not throwing any codes and the check engine light is off. I have not run a fuel pressure test yet because I don't have a guage and no cash to have it done. I also replaced the air filter and the exhaust is not clogged. This has all happened over a two week period. Any help would be great.

 

[Anime]

If it's fuel system issues, I'd say a bad fuel pump or Fuel Pressure Regulator, assuming the fuel pump and ECU relay is good and the pump whirrs on when you first turn the key and allow it to prime.

Don't rule out the most basic of causes. You might want to check the fuses:

http://www.explorerforum.com/forums/showthread.php?t=350598


You should check the ECM/ECU as well, it might be that the previous owner got tired of the constant weird issues that seemed unsolvable, which usually indicates the ECU/ECM has gone, usually from the capacitors leaking. This usually manifests itself by the vehicle not starting and no codes being available, but can also just be a string of weird, endless issues before the thing just won't go. It could be the cap has leaked onto the path for the emissions module on the ECU board, giving all the emissions-related codes.

 

[tacker62]

Did a recheck

I checked the fuses and none look blown. So I rechecked the codes and I received the codes 114 and 116 KOEO and code run code was 136. I am so stressed out by this vehicle. Any help would be great!!!

Tomorrow I will clean the IAC to see if that makes a difference. The wires look clean but have not yet been able to pull the plugs. Does any one know the torque value for the plugs. HELP!!!

 

[Tbars4]

..If you had your location under your name, other members in your area may be available to help you out..

This might be of some help till others chime in..Your codes can be found here..
http://www.explorerforum.com/forums/showthread.php?t=160035

 

[tacker62]

My location is in Minnesota. I am going to pick up a Voltmeter tomorrow, any ideas on what to check the voltage on would be appreciated.
The codes I got are
KOEO
114
(O,R)
IAT sensor out of range - IAT

116
(O,R)
Engine Coolant (ECT) sensor out of range - ECT

Engine running

116
(O,R)
Engine Coolant (ECT) sensor out of range - ECT

136
(R)
Oxygen sensor not switching/system lean Left or Front HO2S - Fuel control

 

[MrShorty]

All four of those codes could easily be operator error -- namely, performing both tests on a cold engine. Unless you know that it was properly preheated, I would suggest repeating the tests, being sure that the engine is at operating temperature before the test.

If you still suspect a fuel system issue, put a fuel pressure gauge on it. If money is tight, see if Autozone or similar will lend out a fuel pressure gauge. Or go to some place like Harbor Freight (their gauge was only $15 or so a few years ago). And note that, technically, the fuel system and O2 system are not really independent. They both are part of the larger system controlling the air/fuel mixture.