Still dies

[Tbates]

It a 97 Cherokee with the 4.0 runs good till it reaches operating temp then dies it will stay running if I idle it up but won't idle I had a known good tp sensor and it didn't work any help would be awsome thanks

 

[69jeepcj]

I was thinking vac leak until I read "runs good till reaches operating temp". MAF, MAP sensor?? I have read these control the fuel, air ratio based on "mass air flow" and "Mass air pressure". I am completely using educated guesses on this so please don't think I have nailed your problem. Get others opinions.

 

[greg92jeepxj]

Hey T , real sorry to hear this problem is still rearing its ugly head in your jeep . I haven't suggested it before because I guess I got too focused on the trouble code but see if this makes sense to you . Runs good until it reaches operating temperature ( closed loop ) which is setting the code . It's vacuum that is is causing the code to trip the MAP , I think , so I'm guessing that either intake or throttle body may be leaking . I don't know if this has been checked previously from past posts but is something to consider . I won't get so extreme as to suggest head bolt stretch as I don't think your engine is losing that kind of power . A compression check ought to confirm engine health but a vacuum gauge , if you can keep it idling well enough to check , can be helpful . At least try at start up since it idles then. This is just a long shot but since this gremlin has not been found , I figure we may as well go for it . I got too rapped up with the code and wasn't thinking of what may cause the fault. If we can ascertain the engines condition , we can at least know what we are working with. Hoping for a good long block and at worst an intake gasket job if not the throttle body. As 69jeepcj suggested , vacuum comes to mind. We must sometimes go back to basics before blaming electronics as it is still an engine like any other bit just modernized with sensors for better emmissions and economy. We got to give respect to the fact that 69jeepcj is real good with old school tech and if he thinks vacuum , he's on to something. When you are around engines that don't have all the electronics and run off basic ignition and fuel systems , you develop an ear for how an engine should run. He's definately on the right track and I think we ought to follow up on that . Nothing else has worked , let's give it a shot. Now I know why he loves old school and hates too much computerized systems , I hate the run around computers give us too ! That's where I got my schooling from , old school tech like he does too !

 

[Tbates]

I put a map sensor in and so far so good in going to put some miles on ot this weekend so we will see

 

[rockfangd]

cool. I was thinking possibly CTS also. they tend to become unreliable overtime and can cause havoc when cold or hot, or all the time.

 

[Tbates]

Yeah that was my next place to look but hope its good for a long time I just rebuilt the motor oil pump went bad and chewed my crank up and all my bearings so I had to tear it down and go through the thing