My 1990 F150 5.0 is giving me fits....

With the engine running, put the truck in reverse and turn the steering wheel....the rpm jump way up, even when I have my foot OFF of the gas and on the brake (automatic trans).

I've checked everything I know of, and cannot find the cause....help.....

Also, how can I identify which trans I have...it is a auto with overdrive...thanks

 

Does it only happen if you turn the wheel? I'm not real real sure how the system works on your truck but most vehicles have a power steering pressure sensor that will bring the idle up when you turn the wheel (to compensate for the pwr steering pumps load on the engine). I wonder if that could be sending a bad signal causing the idle to increase too much.

-Jon

 

Define "way up." Like Ford4ever said it sounds like it's normal to me unless it jumps a thousand revs or something.

As to the tranny ID, there should be a sticker on the door jamb which lists a bunch of vehicle information. At the bottom of the sticker there will be a "Trans" code. It translates as:

E = E4OD
T = AOD
U = AOD/E

 

I sure appreciate the quick responses...

First, I'll check the door sticker for the trans code....lots of help - thanks

Second, the rpm increase is very significant, to the point that I have to hit the brakes to slow it down....I have not actually checked it, but I am sure the rpm jump is at least 1,000 rpm.

I had no idea there was a power steering sensor..where it is located??? Also, the steering is pretty hard, like the pump is not doing its job. I drained and replaced the powersteering fluid, but it made no difference. Do you suppose these two things could be related?? Could it be that ht epump is weak, so there is more pressure exerted on the system and the sensor sends a msg to the engine to rev-it up????? Wow...