Please help

[Peteharris]

I have a 95 jeep wrangler that is have one problem that I can't solve. In the mornings when it's nice and cool out it runs fine. It runs like a new jeep but when it warms up out side later in the day I get a bad hesitation and 2000 to 2500 rpm and no check enginelight comes on. I've replaced everything from coil,cap and rotor, all sensor and fuel pump and fuel filter. I've even replaced the computer. Nothing seems to be helping. Does anyone have any ideas on what it could be or if I'm missing something. Thanks

 

[JPNinPA]

I have a 95 jeep wrangler that is have one problem that I can't solve. In the mornings when it's nice and cool out it runs fine. It runs like a new jeep but when it warms up out side later in the day I get a bad hesitation and 2000 to 2500 rpm and no check enginelight comes on. I've replaced everything from coil,cap and rotor, all sensor and fuel pump and fuel filter. I've even replaced the computer. Nothing seems to be helping. Does anyone have any ideas on what it could be or if I'm missing something. Thanks

When you say all sensors. Does this include tps and o2 and temp sensor to the ECU/PCM?

Have you checked your battery? Weird things happen when batteries start to fail. Or bad wiring and connections. Corrosion at ground contact points.

What rpm do you idle at in the am/cool period vs the later/warm period?

In the warm period how cold gas the engine gotten? Back to cold or still warm to the touch?

How hot is hot?

Never look down on anyone unless you are helping them up - Jesse Jackson

 

[Peteharris]

I've replaced tps and o2 and the temp sensor to the ecu. My battery has no problems. It idles at about 1300 rpm when I first start it then when the engine warms up it idles at 900rpm same for pm start. Now when the out side temp gets above 45 to 50ish degrees that's when I get the hesitation at 2000 to 2500 rpm

 

[JPNinPA]

It should idle at 750 rpm.
You may have a vacuum leak or intake leak.
Start should be 900-1000 for 1-2 min then 750 after.

How do you know your battery has no problems? What test were done and what about the ground wires and contact points?
Have you checked your fuel pressure cold and hot across the 2000-2500 rpm range?


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[JPNinPA]

Also have you ever cleaned out throttle body?

And the sensors, did you use OEM sensors? Jeeps are finicky and many aftermarket knockoffs are bad out of the box.


Regards,
JPNinPA

Never look down on anybody unless you're helping them up. -Jesse Jackson