I have made another post about how my jeep is acting....
https://www.cherokeeforum.com/f2/dis...or-woes-41089/
but I am at a loss about this thing and at the same time I am wanting it fixed ASAP.
Can a bad TPS cause, backfiring and jerking? I put it to the floor under these conditions and it clears up and takes off.

 

yes it can it can also cause ur truck not to shift

 

the truck is shifting, so I am not sure.

 

mine dose the same thing its got me crazy it might be the tps but i think it has alot to do wit the vacum hoses may b let me no if u find out wat it is

 

I just replaced mine yesterday.

My syptoms were:

-when cold, if i let off the gas it would conk out
-Throttle response was almost nonexistant, i would throttle then a few seconds later it would try to kick in slowly, then jerk foward then slow down
-wouldnt shift till about 2800 revs, and it wouldnt shift till it had been at 2800 revs for about 30 seconds
-One day it wouldnt get out of first gear
-Sometimes on the interstte i couldnt make it past 50-60mph, once i got there the reves started bouncing and it wouldnt change gears..

lemme know if i can help anymore, mine sent a code, but not till about a week after i started noticing the above stuff...

 

That was my next question, could it be a bad TPS and not set a code? I have watched the voltage for the TPS slowly pushing the throttle and voltage increased steady

 

also check plug wires.....

 

just a tune-up cap,rotor,plugs,and wires not long ago. checked the firing order today and pulled the cap and looked inside at the rotor and stuff. (it was doing this before the tune-up too)

 

I think I am going to try the TPS tomorrow. I just hate throwing parts at it and not being sure.

 

Replacing the TPS is never really a bad idea, though. Most Jeeps are still rockin' the stock TPS, and like any part they wear out over time. Mine was causing my Jeep to hold onto revs until it hit 3k, then maybe, MAYBE it would decide to shift. Replaced the TPS, and it fixed all my shifting issues.

As others mentioned though, it could be an ignition issue. Check your plugs and wires.

 

Yea I figure I am going to go ahead and change the TPS tomorrow. The cap (duralast),rotor (duralast),plugs (champion) and wires (bosch) are new. I looked at the cap and rotor tonight and they look good. (no abnormal wear). Heck just replaced them less the 50 miles ago, (and it was doing this before)

 

Did you get this fixed? If not, my jeep has the exact same symptoms as yours. Mine also bucks suddenly at certain throttle positions, nail the throttle and away she goes. Thought TPS myself as well but had codes checked and turns out to be a crankshaft and or camshaft position sensor. The code P1391 is a Chrysler dealer code that doesn't appear in the code book. Apparently, you can turn your ignition switch to on(without starting) and off, and on, and off, and then on and leave it there. Count the flashes of your check engine light in your cluster. If it blinks 11 times, this is your problem as well.

Cheers

 

would me replacing the crankshaft sensor cause this problem? i think mine is also the tps cause it did this before i replaced the crankshaft sensor.

 

I'd put some money down on a TPS. Its easily replaced and will save you mpg's. I've had the same issues with both my XJ and WJ. The XJ snorted some water and had a bunch of similar symptoms (coughing and conking/no overdrive), and the WJ just went bad after 100k miles. I thought I had tranny problems until I looked into the TPS. Problems solved. Lifetime warranty on Borgman TPS. Good luck

 

I am having almost the exact same issues. Bogging down and bucking in the mid-rev range, and she is just sucking down fuel. I have an 89 Cherokee with a manual transmission, so no shifting issues. It also is a vacuum line nightmare, as the previous owner was a tad ... mechanically ignorant ... I (believe) I have fixed all the vacuum issues, but I'm still guzzling fuel and bucking mid-gear. I unplugged the tps, and saw absolutely no difference in the symptoms or driving preformance, so I assume it's shot, but I would like a second opinion before slapping down 150 bucks for a new one.