Recently purchased an x J from a friend of mine drove it three hours from where he lives to where I live not a single problem got home and now the vehicle when it gets to operating temperature stalls, and sputters I checked the vacuum lines. I have checked and made sure the throttle bodies clean and I’ve replaced a plethora of sensors and that list is as follows crank position, sensor, throttle, position, sensor, map sensor, camshaft, position sensor a little further note that it did have a vacuum leak from the brake booster check valve and I replaced that the idle got better but it still stalls when driving I also for ****s and giggles replaced the air filter thinking that may be the old one was just not up to par. I also have replaced all of the spark plugs in the ignition coil. It has a fresh oil change on it and all the fluids are good. I’m kind of at a loss with this one though there are no codes and I tried to use Alpha OBD, but it doesn’t support the year or the model my brain is telling me it’s a fuel related issue, but the vehicle starts and it runs without having any problems until it gets to operating temperature and a little bit of me tells me it’s the vacuum line maybe sucking in hot air somewhere or losing pressure but I’ve sprayed them all and none of them seem to change the idle at all. Does anyone have any recommendations on this?

 

First up is what year did you get ?? If you've been reading up on here you already know the cheap auto parts store sensors are usually more trouble than they're worth so hopefully you bought quality parts... I'm not seeing oxygen sensors on the list I myself would have made those one of the first sensors to change out after the vacuum system troubleshooting if I was just going to fire the parts cannon at it...

 

it is a 2001 and sadly to say I went to rock auto I did buy from them selecting the reputable brands or brands that I know I do have the o2 sensors but haven’t replaced just yet

 

2 things I would do

1) Look at live data via OBD and Torque lite free App on phone

2) Put an old fashioned engine vacuum gauge on it

I cant read your post all that good, but if it gets hots and splutters, remove the coil and inspect it..if its all cracked behind there is a good chance it needs replacing

retain all original sensors, dont throw them out

 

What is the temp gauge telling you when the engine is warmed up? If it's low you may have a bad or wrong temp thermostat. The engine needs the temp to be around 195° in order to run properly.

Did you clamp off the brake booster vacuum line? You may have a vacuum booster leak. I agree that you need to verify vacuum level with a gauge.

Throwing parts at a problem without diagnosis is a waste of time, money and effort. Spend your money on some basic test equipment and diagnose the problem. This will save you time, money and effort

 

so I wanted to share my findings on the sensors … shoulda taken them out and inspected and not been lazy

 

Yeah, that'll do it...lol... Glad you found the problem... Once up to operating temp the oxygen sensors will show you what they can or can't do... Pretty much a text book failure with those symptoms ...