Backroads Posted April 28, 2011 Share Posted April 28, 2011 Just got this MJ. Got it from a previous member here, seems like at times he had the problem too... It seems that when accelerating, or holding a constant throttle position, it hesitates, surges a little...not quite bucking, but a mild version of bucking if you wanna call it that. It seems like the warmer it gets (engine temp and air temp) it gets worse. My first thought was TPS. Just swapped that out..with a JY part mind you so theres a chance thats bad too. I just can't cough up $100+ for a new one. Any kind of way to trouble shoot this other than throwing money at different sensors? I guess CPS is another possibility.... Is there any kind of diagnostic I can run on it? Its an 88 4.0 5 speed. 2wd if that matters. Thanks! Also, whats the best method for testing a TPS. I have a multimeter I just don't get how I can probe the connections when its plugged in, short of splicing into the wire to make contact. Link to comment Share on other sites More sharing options...
tbrand Posted April 28, 2011 Share Posted April 28, 2011 My '89 had a hesitation under acceleration - it would bog down for a second, then go like you wanted it to. It turned out to be the oxygen sensor. Kinda spendy, but it made a world of difference. Link to comment Share on other sites More sharing options...
fiatslug87 Posted April 28, 2011 Share Posted April 28, 2011 Check the EGR system. Link to comment Share on other sites More sharing options...
Backroads Posted April 28, 2011 Author Share Posted April 28, 2011 Thanks for the ideas. O2 sensor was another thought. Expensive sure but at least it feels more worth it than the same money for a stupid little tps! Egr seems like a major pain in the neck, hope its not that. Link to comment Share on other sites More sharing options...
Backroads Posted May 1, 2011 Author Share Posted May 1, 2011 Ended up being the o2. I tested the sensor and it was reading a constant 4v so took the shot and got a new bosch. Drove it a few miles up to full temp and seemed to be driving normal. It was worse when it was kinda hot this past week and tonight its a nice 60' outside so hopefully that solved it! On a side note I'm sorta surprised that was it. Granted this was my first tank of gas through it but i managed about 18 mpg. I figured it would be a lot worse if the o2 was going out! Link to comment Share on other sites More sharing options...
tbrand Posted May 1, 2011 Share Posted May 1, 2011 I was pulling 20 or 21 with my O2 sensor going out... I was hoping for a nice bump too, but it didn't happen. Link to comment Share on other sites More sharing options...
Backroads Posted May 1, 2011 Author Share Posted May 1, 2011 Id be happy to squeeze a few more mpgs out of t. Been getting the worst side of 15 mpg is every other vehicle ive owned for a while now! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now