Please Help me! 2002 explorer bucking

[024x4beast]

for all keeping up thus far

so with nothing else working to fix this problem we finally broke down today and bought a new DPFE sensor AND a new coil pack only to find out that neither of these are the issue. Dont get me wrong the combination between these two did make a difference.

However: after changing the DPFE out and driving 30 miles my CEL FINALLLYYY came on. we hooked up the OBD2 and pulled the code P0171 (O2 sensor lean on bank 1).

After disconnecting the battery and replacing the coil pack the light has gone out but alas the other problems (i.e- bucking, and low-but rough idle, and almost stalling out) are still there.

SON OF A ......

so frustrated.

convinced its NOT the transmission. its gotta be somewhere in the fuel/ignition.

 

[swshawaii]

Maybe? The 2002 4.0L SOHC shows having this PCV elbow.

http://www.explorerforum.com/forums/showthread.php?t=314670

 

[024x4beast]

swshawaii- thanks for that post we hadnt seen that one yet but again, thats not the issue either.

took the whole intake manifold off and cleaned around the injectors and are now actually going to clean the injectors themselves..... although i do not believe that this is the actual problem.

the only other thing that we have left to do to figure it out is to replace the 4x4 control module.

other than this i have NO CLUE whats goin on.

 

[tman1257]

My 03 with the 4.0 soch has been having an issue similar to this also. I have a new coil pack, plugs, and fuel filter has 25k on it. The plug wires have about 35k on them. I have cleaned the throttle body, maf and put a new air filter in. Mine starts and idles good but under a load in 1st and sometimes second it will buck a little on the top end of the revs. So I am watching this to see what else I can try also.

 

[024x4beast]

tman

My 03 with the 4.0 soch has been having an issue similar to this also. I have a new coil pack, plugs, and fuel filter has 25k on it. The plug wires have about 35k on them. I have cleaned the throttle body, maf and put a new air filter in. Mine starts and idles good but under a load in 1st and sometimes second it will buck a little on the top end of the revs. So I am watching this to see what else I can try also.

if you find anything please let me know! im going insane trying to figure this out

 

[tman1257]

Well Ive also had a trans fluid flush done about 10k ago so Im hoping that will help to rule out a trans problem. All of the aforementioned stuff I did to it seemed to help it but not take care of the issue. About the only thing I can think of to do next will be to check the fuel pressure. After that I will probably have to go have it scanned to see if anything shows up.

 

[024x4beast]

Well the bucking problem is temporarily solved. Unplug the motor on the transfer case to the 4x4 and it will go back to staying in 2wd. For me the bucking was caused by my 4x4 being engaged but the dash light never illuminated. Still trying to figure out the low/ rough idle. Oh the joy.(sarcasm)