ok i've owned my 89 cherokee for 15yrs. and this is new. one day it started jerking and bucking on me on the highway. and twice as bad when i went thru a big left turn. eventothepoint of backfiring. I've replaced the fuel pump, fuel filter, distributor cap, plugs cleaned the air idle control valve, replaced the airfilter. new muffler "it had a huge hole in it". all in the last 6 weeks. nothing has changed anything til i changed the MAP sensor ran like a champ for 4 days then stared with the same old crap. returned the MAP for a better one. ran like a champ for another 4 days then crappin out again just like before jerkin and bucking on the bypass with the rpm needle all over the place. I just unplugged my O2 sensor It ran to work fine except for one buck or jerk, but on the way home same old story. does anyone know what it is? please help

 

tps ,throtle position sensor??? does it bog down an over rev
when it jerks

 

no not really, I can be driving along just fine then it starts, I can take my foot off the accelerator and the rpm needle is still jumping all over the place, as it slows down and people are on my tail I can floor it to about 3k rpm and sorta power thru it. i was getting alot of oil blow by in my intake. so i cleaned all the burnt oil buildup off the air idle control valve. ran great for about 10 miles. Map sensor ran better than it had for 10 years for about 4 days, repeat on new MAP. unplug o2 sensor and fine for 12 miles went to drive home from work and same old crap, so i don't know

 

does it do it when sitting still and you turn the wheel also?

 

No I can be in park and rev it to 3k and it run just fine. I can turn the wheel left and right and it acts just fine. So maybe crankshaft position sensor since it actually has to be moving. The vehicle can be in gear and rev it to 3k with foot on the brake and still just fine. So what do you guys think?

 

fuel pump suspect ive heard alot of people mention pick up hose comin loose

 

No new ignition wires?

 

You think the TPS could be the culprit? Im having the same problem with my 01, but mine only does it around 60 to 75MPH. When it jerks the RPM's go up about 200 RPM's and then come back down. Any Ideas? Sorry dont mean to thread jack but I figured why start a new thread that sounds so similar to this one

 

2 different fuel injection systems.

 

Yeah I know they are totally different(I also own a 90 XJ). Any ideas what can be causing this on my 01? I really dont want to start a new thread to ask the same question. Thanks for any help.