ok guys im trying to sell this 1987 F250 and it dosnt really help when the auto tranny wont shift on a test drive.......no i dont know what tranny i have in it...all i know is its automatic......it feels like its stuck in2nd and 3rd gear...it takes a long time to get up to speed because you have to feather it gently. and when i hit a hill the fastest i can go is like 20 tops because i cant push the pedal down any further or its revving at like 5K rpm and im srill only doing 20 then the engine starts poping and sounds like a few cylinders are just falling outuntill i ease back up on the throttle....WTF....can anybody help me....please?

 

is your spedometer working... check the fuses to see if any have blown

 

yes my spedometer is working. ill check the fuses tomorrow but back in the fall, not the shifting problem but it would loose all power and it would pop and cough and stall. so we took it to the shop and the guy said there is some big plug up under the passenger side dash that was loose and was causing this. he fixed it and its been running fine since....now im thinking it has come loose again and maye its not telling the trsmission when to shift? just thinking out loud here. he never specified on EXACTLY where this big plug is up there so if anyone knows plz tell me so i can check it...or at least what the name of it is so i can look it up in my haynes manual....

 

my truck was having troubole shifting in general caus ethe fuse for the electromnic shfting was blown, hat fuse happened to be connected to the spedometer and odometer as well.. im not too sure about the 1987 if they uded electronic shifting or not... do you have "Overdrive"? if you do it may be the E4OD tranny which is known for a problem similar to this which my truck also had

 

no overdirve....

 

It sounds like the transmission is slipping if your turning 5000 RPM's at 20 mph. The falling out could be the valves floating from over revving the engine. Have you checked the fluid? Does it smell burnt?

 

fresh fluid....just flushed last summer....good level and condition.....

 

It sounds like you have a C-6, which I don't believe is electronically controlled, someone correct me if I'm wrong. If this is the case, then I don't think the loose plug that you mentioned could be causing the tranny to not shift at the correct places. It sounds like you have an engine problem, possibly an issue with the EGR?

-Chris

 

c6 ha a modulator valve at the rear of the trans
that controls the shifting
a vacuum line from the engine is connected to it
check the line at both the valve and the engine as
this is a common problem
sounds like your never gettting out of first gear
if vacuum is present try shifting manually 1,2, drive
if this works then will probably need a new valve

 

PROBLEM SOLVED!!!!!!!! after some thorough problem solving on AIM between me and Skandocious we determined that it is doing EXACTLY what it was doing last summer before we took it to a mech and he said there was a large plug up under the dashboard on the passenger side of the truck. i took off that side kick panel and sure enough i found a big green plug with 8 wires goin in each side.....i took it apart and blew some compressed air on the prongs and put it all back together and now this truck is SCREAMIN through the gears runnin really good.....i still dont know what this big green plug is called.....if you know what it is plz tell me so ill know for suture reference...but that was the problem....damn green plug...lol....