I have read through several threads, but have not been able to find a solution to my problem and I need some help. 1999 Cherokee XJ 4.0 with 156K. From a cold start (until it hits about 180*) if you hit the accelerator it will bog down and die if you don't give press the accelerator harder. I am not a mechanic by any means, but I started replacing several of the cheap sensors that can typically cause issues. So far I have replaced, TPS, IAC, Coolant temperature sensor, MAP, and both O2 sensors. The grounds look clean and there is no noticeable vacuum leak and all of the hoses look good. Once it hits operating temperature it has no issues. What can I do next?

 

I think you should check the fuel pressure

 

Yeah, what he said!!!

 

.. ......... with a gauge

 

I will see if I can get a gauge on it this week and check it out. The reason I started with sensors is that the problem goes away once it reaches operating temperature.

 

Hooked it up to the gauge today and it was steady at 42psi and held for 2 minutes after without the engine running, and 48psi during and 2 minutes after with the engine running. I pulled the hose on the throttle body to ensure it was clean and there is zero build-up on the throttle body. Plugs, wires, and battery were all done before I purchased it but still look great. Is there an easy way to test the injectors without pulling them out to look at them?