Jeep Inline 6 troubleshooting...

[Bowhuntamistad]

Our '99 Grand Cherokee is fluctuating rpms rapidly between 1-2k, bottoming out, and then stalling while driving. Other times it is just stalling when put into reverse. At other times, it is almost like it slips back into 1st gear or something when driving and drags.

Anybody have an idea what it might be?

My wife seems to think its the starter or fuel pump

[Team me]

Sounds like a fuel injection system problem. Sensor bad ? Have you tried to get the codes read at autozone ?

[Bowhuntamistad]

Sounds like a fuel injection system problem. Sensor bad ? Have you tried to get the codes read at autozone ?

Only if it could make it to autozone

[csmetreyeon]

But a cheap code reader you can get them for around 80 bucks at the auto parts store if you can find a ride to one.

[Bowhuntamistad]

Ttt

[Jared L]

Sounds like a jeep! Lol

[stickflinger09]

Make sure you don't have a vacuum leak anywhere

[bigjohntex]

Tps possibly. Throttle position sensor

[Texas-Red]

If its an auto tranny it could be the torque converter.

[Buckwheat]

Make sure you don't have a vacuum leak anywhere

^^^^this. EGR. TPS. Crankshaft positioning sensor( this would usually just go out but not always).

Just
Empty
Every
Pocketj

[175gr7.62]

I will almost bet you a paycheck that is is the throttle position sensor. Very easy to replace. When you do it, also remove you Idle Air Control motor and clean the plunger on it.

[Bowhuntamistad]

Doesn't sound to expensive then...maybe even DIY?

[175gr7.62]

TPS runs about $60. Two screws hold it in. Same thing on the Idle Air Control Motor. Its best to pull the throttle body off (4 screws) and clean it out really well. It's about a 2 beer job.

[TX_bowhunter37]

Catlaic converter maybe

[ra61hunting]

If the jeeps are like other Chrys products you don't need a code reader to pull the codes. Turn your ign key on, off, on, off then on and leave it on. If your car is old enough to have the OBD1 system your check engine lite will flash several times then pause and flash several more times. the number of flashes is the first digit of the code after the pause is the second digit. It will pause again and repeat for all codes. they are 2digit codes on OBD1. 55 is the code for finished. If you have the OBD 2 system the codes will display where your odmeter readout is. They are 4 or five digits.
My wifes Neon had the same symptoms as you described and it was the Camshaft Postion Sensor. If you have more than one code fix the last code first and see if it clears the other codes before going to the next one. You can google the codes or purchase an OBD 2 manual (Chilton or Haynes) that will have a list of most codes.