95 XLT 4x4 loses power under load

[XtremeXplorer]

I have a 1995 XLT 4x4 with 112k miles on the OHV 4.0 and the original 4R55E trans. Since about 65K miles it has had an odd problem that I cannot seem to solve. When I am driving normally, It accelerates smoothly and shifts through the gears fine. When I am under heavy to full throttle situations on all roads (save for a downhill run), Between second and third gears @ around 3500-3600rpms, i get a slight drop in the rpms and power, and then a little bit later the tach jumps back up to where it should have been without the drop. If I am under hard/full throttle accleration up a hill, i get a 500-600 rpm drop, and if the run is long enough, it will go back up to where it should have been (w/o the drop). The truck has always received regular and preventative maint. And oil changes never go longer than 5000 miles (i drive LOTS of freeway). Since about 95K I have replaced the EGR, PCV, both O2 sensors, and just this evening, I cleaned the Mass Air Meter (email me if you wanna know how to do this...a task and a half, but if your poor its worth it), replaced the plugs with OE autolite platinums, air filter, etc. At 110K I also did a thorough cleaning of trhe throttle body by completely removing it from the motor. I still have the same problem, and really cannot get anyone to tell me if they know a way to fix it. The dealers are completely useless, and I am just hoping the someone can give me a hand. Please let me know if you guys know of a fix or a simple solution. Thanks, XtremeXplorer... Sorry bout the length of this guys, but I thought I would give you all the info, so as to eliminate some common questions! PEACE!

 

[JUST4X4FUN]

Hi , xtreme you didnt say if the Check engen lite came on well i think its eather the speed sensor
or TPS leaning more towards the TPS ...Larry

 

[XtremeXplorer]

Thanks Larry

Larry, that is the one thing that I forgot to mention in the list. A few months ago at around 97K a buddy and I had traded cars for a few days. I had his 1995 M3 BMW and he had the X. He called me one night and asked if there was a reason teh OD Off light was flashing. I freaked, talked to 3 dealers, and they all gave me the woe is me tranny story. I found a post on another Ford BBS and a guy described my exact problem (sloppy shifts, odd throttle response, etc) which in my original estimation was thinking trans. Well his reply to the post sternly stated that he felt it was the TPS because of all the TPS dealt with. Long and the short, I felt a 20buck TPS was worth a try over a trans job. So, I threw it in with the BMW buddy. Reconected the batt, and voila... problem solved. Sorry, that was kinda long winded, BUT Might help someone else out with similar probs. Also, I talked about it with a buddy of mine, and spent about 4 hours on the net last night, and an hour driving the X around. I think it is low pressure in the trans, causing premature engagement of the Torque Convertor. MONTHS ago when I put in the transgo shift kit the guy recommended that with my mileage to replace the two band servos, and the EPC (electronic pressure control) solenoid. I was PO PO at the time and asked if I could wait on that. He felt that some of the little issues I was mentioning were definitely pressure related (or a lack there of). I now feel that this could be the problem, and Since I need another trans service am going to do it with a buddy of mine, and replace the TC (torque convertor) solenoid at the same time. Tell me what you think if the length of this post has not brought u to tears! Thanks bro for your input.

PEACE!

 

[JUST4X4FUN]

Hi
try the trans guy again he should be able to hook a scan tool up and get the presure readings from that.
Wow i would like to trade my X for a day for a 3M
but does someone have bail money . good luck keep me posted...Larry