bigvig

Hey everyone. My wifes sister is up for a visit and her boyfriend drives a 98 Sport. They just took off to the store and his Jeep is locked up but Ive got a couple questions:

He says when he starts it, is runs a little rough and sputters a but and if he takes off it will sputter/knock a bit and if he lets off, its ok. BUT, if he gives it the gas it sputters/knocks and stalls.

Anyone have any ideas? Like I said, they went to the store and its locked up so I dont know if it has a throttle body (my guess), or a carburetor which someone told him, etc., so Im not sure if its a sensor (my guess) or something else. Thanks!

xj^REMY

definitely not carburetor....it has a throttle body...problem could be with throttle position sensor (TPS), mass air flow sensor (MAF), manifold absolute pressure sensor (MAP), idle air control (IAC) or faulty/clogged fuel filter/pump (in a 98, filter & pump are 1 assembly, inside the gas tank)

doesnt accelerate at all?? check engine light on yet?

bigvig

Well, just got back in from looking at it. No visible, obvious issues. Definitely throttle body (my mother in laws boyfriend told him it was a carburetor, wish he had of told me that to begin with, would have explained a lot) and nothing looks out of order. I told him he should take it to Autozone or Sears or someplace to have it hooked to a computer and see whats going on as its probably a sensor. No "check" light, and I guess its been doing this for a while.

He doesnt know ANYTHING about Jeeps, so Im going by what he's asking. He says if he doesnt let it "warm up" and he trys to give it gas, it will flat out stall. If he babies it, it will go but not well, so he just lets it "warm up".

xjguy383

I would assume it to be the Throttle Position Sensor (TPS).
But also in my previous '97 XJ, it did that, and my temp gauge was also goofy but it caused same issue. Mine turned out to be the thermostat sensor.

xj^REMY

i havent experienced problems like this, but i had an issue in the past with Crankshaft position sensor...xj would stall out completely without warning...didnt matter if it was warm or cold....after stall, would turn on right away, or after 3 tries, or after 7, or after 10....never had a pattern

regarding ur problem, tried to search for one specific solution with the same symptoms, but there really isnt

read thru these...
https://www.cherokeeforum.com/f2/98-...g-accel-54445/
http://forums.cnet.com/7723-7811_102-311804.html

some end up being the TPS, or MAP, or Camshaft Position Sensor....others might be a cracked distributor cap...in some cases, the ECM (computer) needs replacing...start with basic tune up, spark plugs, wires, distributor cap & rotor

if u have a multi-meter, patience, time, & knowledge of electrical circuits/components, u can go thru things to pin-point....if not, then change one thing at a time, & keep ur fingers crossed

bigvig

I appreciate the help, but this is a guy Ive never met until last night. Doubt Ill ever see him again in my life and he hasnt got a CLUE about Jeeps. He bought it new in 1998 and it just turned 110K on his way up here (can you IMAGINE!) and he thinks its probably time to "junk it" because its old. He would be more apt to take it to a garage, hear whatever they have to say and decide whether or not to fix it or scrap it. I was just trying to help the dude out last night when he was here because he's my sister-in-laws boyfriend. I do appreciate the response though. Thanks.

xj^REMY

no problem, looks like we both share a soft spots for XJ's & hate to see one hurt & mistreated

as far as he's concerned, tell him to "junk" it in my direction, & buy himself a hyundai