newbie need help

91 cherokee,4.0L,4x4.Last week my XJ was shifting funny. It wouldn't downshift ino 1st on its own Tranny shop said a solenoid was bad. Replace teh solenoids,the fluid and filter.Ran great all weekend now the tranny is doing somethng different.When it shifts into 2nd. It almost immediatly goes into 3rd.Sometimes in won't shift into over drive and just stay in 3.But the tranny is intermitant. At times it is just fine than it will start doing it thing then quit. I am also having a starting issue. I know it is normal for jeep to crank a llittle before firing but sometimes mine will just crank.If I pull out the fuel pump relay,and the ignition fuse and put them back in cranks on over and fires. So I wonder if I have an electical issue issue somewhere.It was scanned at the tranny shop and a wierd code came up that said 42no21volt.Maybe TPS?? any help would be great.

Sounds something like mine is doing. Hard start, and shifting to fast. But is always goes into overdrive. I have no downshift to paaing gear. I am replacing the TPS today. I have a RenX so might be different...

Sounds like either the TPS or TCU is going bad. Your starting issue could be caused by the CPS (crank position sensor).

If it is the TCU, you can unhook it and manually shift. It is located on the back of the pannel under the glove box.

Daddycajun: check/reset your kickdown cable. That might help out as well, at least with no passing gear.

On the other hand....my 89 won't kick down @ 55 unless I go WOT, then it drops down to 2nd =P

Yeah I messed with the TV Kickdown cable. No good

I'll put my money on both of them being a bad TPS, loose TPS ground wire or both.

TPs Fixed the problem I am shifting normal. Did have a bad day. Replaced TPS and was ready to go when my fuel pump decided to go out. But after all that everything works. Need to do a little adjusting