i just bought 1987 xj with the aw4 trans!! when i am driving it at like 45 mph it feels and sounds like the rpm are jumping up and down!! and it feel like the trans is slipping a lil bit!! any help would be great!!

 

Trans is just fine but as crazy as this sounds it is the TPS. It may be just out of asdjustment or may need to be replaced. The TPS is telling the computer to lock and unlock the torque converter and it mimics the upshift/downshift feel and action you are seeing. I have been through this several times and is difficult to make you understand that it is really unrelated to the trans. Try the adjustment first and if that does not help then replace and adjust the new TPS and your problem will disappear.

 

thank you i am going to go out after work today and try that i will let you know what it is!!

 

Mine would jump around too at 30 MPH and once again as crazy as it may sound mine was solved by unplugging and then replugging in the CPS.

TPS and CPS are common problems with the XJ and they cause a lot of different problems.

 

I'm not sure if they still had them on those trannies, but I know I had a full size Dodge van with a 727 in it, and I had a problem wth the converter lock up solenoid.