[grandchero]

My wife ran out of gas on my 00 grand cherokee about 3 or 4 times. It starts up fine now but when it warms up it starts to lose power when you drive. Could this be the fuel filter pulling trash cause it ran out so many times.

 

[Trav1s]

The fuel pump is located in the tank and gas is used to keep it cool. Repeated running low/empty can cause them to go bad. I would suggest replacing the fuel filter (includes internal pressure regulator and is located above the rear axle) first and go from there. Let us know how things go for you!

 

[grandchero]

Thanks I am going to try that first and let you know how everthing turns out.

 

[grandchero]

It did not work. I think it has something to do with my p0123 code (high voltage to tps). Can somebody help me. I changed the tps (with dealer one) and the wiring and got the clockspring unplugged.

 

[Frango100]

Did you change the wiring to the TPS?
Check the connectors on the PCM (remove them and check for moisture/corrosion/dirt), but there is a good change that the PCM is the problem.

 

[grandchero]

Yes I changed the tps harness. When it get warmed up the lights dim when I press the gas. Is it a way to check the pcm?

 

[Frango100]

Yes I changed the tps harness. When it get warmed up the lights dim when I press the gas. Is it a way to check the pcm?

Headlights dim or instrument lights? Have a look at the battery voltage first, because a bad battery or alternator problem could generate strange behaviour. You could try to disconnect the alternator cable, isolate it with isolation tape and drive a bit to see if the problem is gone. Remove the cable with engine off, to prevent voltage spikes. Logically the battery will not be charged, so do this only as a test for a short time.
No good way to check a PCM without special test equipment.

 

[grandchero]

Ok im going to try that out and let you know the results.

 

[grandchero]

Sorry it took so long. I got the check engine light to go off but it is still bogging when it warms up. Could it be something with the throttle body?

 

[Frango100]

Check engine light is off, but is the code gone as well?
Did you check the battery voltage with engine off and engine on?

 

[grandchero]

I will do that next. I know I did have battery problems before. Would that make the rpms not go to 2000?

 

[Frango100]

I will do that next. I know I did have battery problems before. Would that make the rpms not go to 2000?

I was more thinking towards the alternator, so just to rule this out its good to know what the voltage is with engine off and engine on. It maybe has noting to do with it, but because you mentioned the lights go dim when pressing the gas its good to check.

 

[grandchero]

Ok battery and alternator checked out good. It starts up soon as I turn the key. But when it warm up I cant rev it to 2000 rpm. It makes a bogging sound and drops back down. Sound like its coming from the throttle.

 

[Frango100]

Is there any fault code set at the moment?
Do you have a scanner to see live data?
Did you check the battery voltage while accelerating the engine, because its then when the problem starts.

 

[grandchero]

I dont have a data scanner. The dim lighting issue is not a problem anymore. It wont rev to 2000 rpm. It goes up then drops back down after it warms up. And I dont have anymore codes after I fixed the p0123 code.

 

[CNY_WK2]

Shot in the dark but possible dirty MAF ( Not sure if it is a maf or air density sensor)

 

[grandchero]

How do you clean it?

 

[Frango100]

Don´t know which engine you have, but both 4.0 and 4.7 have a MAP sensor. On the 4.0 its mounted on the throttle body and on the 4.7 on the front of the intake plenum. MAP is the number one input for fuel injector pulse. I don´t know of any cleaning of this sensor and the fact that the engine works fine when cold, i won´t expect it to be dirty. It could be faulty though.
But without observing the live data, it will be a shot in the dark.
If you have an android phone, you could download the free app Torque and just buy a cheap bluetooth dongle for the wireless connection to the jeep. This app can show you MAP, O2 sensor(s), inlet temperature and coolant temperature and many other live data, which could add in the trouble shooting.

 

[grandchero]

A mechanic I know said it could be some bad gas. He suggested some lucas fuel treatment and a couple of gallons of 93 octane gas on top of it.

 

[grandchero]

It didnt work. Im going to try the app.