Help! I drive a 97 Grand Cherokee, straight 6, 4x4 and am having almost stalling problems. Not consistent either. Had problems recently, wants to stall after taking off from a stop light and recently been idling low. I had a friend clean the Idle Speed Sensor terminal and drove it for a week and a half with no problem. Then today after driving for about 20 minutes it started choking again. Pulled over for 20 minutes and it drove home just fine. Husband is a big time Jeeper with a lifter 97 Cherokee but he is deployed at this time! Need to know what to look for. Other threads I read talked about the CPS. Have also already changed the distributor cap and rotor.

Does it miss when it stalls or almost stalls? Could be the IAC on the back of the Throttle body, its a common problem with jeeps. If it is missing it could be a range of things fuel pump, cps, wires , plugs. The way the IAC acts up is when you are driving and let off the gas it will stall or when you come to a stop. When you had it cleaned Ithink you meant The Iac Idle Air Control Motor they might not got all the carbon out or it could be bad.

also it may be time to change the Fuel filter, and mayeb Plugs and Wires if they haven't been changed in awhile.

Thanks for the info on the IAC as I think I'm eliminating that as the problem. The stalling happens when I try to accelerate. Was reading through Haynes last night and wrote that down as a possibility though. Just wasn't sure exactly what symptoms would present. And yeah, probably did mean to say IAC-I'm not much of a mechanic! Ha! Going to have a friend help me test the CPS this weekend. My initial thought when this all started was fuel pump but now I'm not so sure because it is so inconsisent. Like I said, sometimes it runs fine. What about Throttle Position Sensor-what would that feel like? Plugs are good also. Thanks again in advance.

Could be TPS they usally throw a code when bad, easy to check with a Scan Tool. You can use DVOM onthe 20 volt scale. Have to disconect the TPS connection and run jumper wires from the harness to the sensor. Should have around 1 volt at closed throttle and gradually increase to 4 to 5 volts as you open the throttle. Onthe CPS un hook the harness connection and use A DVOM on the 1 to 10 k scale if sensor is good there should be no resistance. Also you need to check for fuel pressure.

cerismc - email me I will send u instructions on testing the TPS. but it wouldn't cause the jeep to stall.

I have a '93 Grand Cherokee that has a similar problem. While idling the rpms will drop down almost to 0 and either pop back up, then drop, then pop up again....or it will just stall. This problem is sporatic though. Any ideas?

Thanks for the TPS info Cam and dk. Going to a friend's house this weekend to test the CPS. Haynes says to use a analog voltmeter instead of a DVOM to test the CPS...why is that? Just curious. I will keep you posted on the progress by early next week. Bassb69, fyi mine never actually stalls out completely. dk, I'll email you for the TPS instructions just in case. Like I said, the Jeep never actually dies though. Much appreciated for all of your help guys.

well if it doesn't sie then, it is most likely the TPS like Cam mentioned, email me I will send those instructions.

bass, your sounds like it might be the IAC going whack. it may just need a good cleaning (throttle body and ports)

I have a 1993 grand cherkoee. I have changed the plugs & wires, cap & rotor, air filter, given it an oil change, cleaned out the fuel injectors and throttle body. I also relpaced some cracked hose on the engine. All of these small repairs have greatly improved the performance of the Jeep, but the problem remains...when in drive only, and I am stopped, or creeping forward to a stop sign from a stop, the jeep will sometimes drop way low down to 0 while idling and will rev back up after shuddering severely briefly. Sometimes it straight up just stalls completely, but will start right back up with no trouble starting. The problem has been getting worse and happens more frequently. Anyone know what might be the problem? I would rather have an idea before I take it to get it looked at as I have already poured a lot of money into this car. Thanks, much appreciated!

I have a 1993 grand cherkoee. I have changed the plugs & wires, cap & rotor, air filter, given it an oil change, cleaned out the fuel injectors and throttle body. I also relpaced some cracked hose on the engine. All of these small repairs have greatly improved the performance of the Jeep, but the problem remains...when in drive only, and I am stopped, or creeping forward to a stop sign from a stop, the jeep will sometimes drop way low down to 0 while idling and will rev back up after shuddering severely briefly. Sometimes it straight up just stalls completely, but will start right back up with no trouble starting. The problem has been getting worse and happens more frequently. Anyone know what might be the problem? I would rather have an idea before I take it to get it looked at as I have already poured a lot of money into this car. Thanks, much appreciated!



3 things come top mind as possibel problem the first and prolly most obvious CrankShaft Position Sensor. Throttle Position Sensor, or Idle Air Control.

ok thanks a lot, any advice who to take it to to check it out or what price im probably looking at? thanks!

CPS sounds like the culprit, although with a bad CPS starting will usually be very difficult, and the Jeep will either run or stall, not really "stumble." I suppose you may have a bad connection or something of that nature, but it just doesn't sound like any CPS symptom I've heard. Also, i doubt it's the IAC because if you are accelerating the IAC no longer plays a role in the motor.

Oh, Hayned reccomends the analog meter over the digital, because analag will give you a much more accurate reading if the test only takes (milliseconds.) Digitals usually take a bit of time to register and display, and by the time they go through all of this you will not get an accurate reading.

MATT the problem exist while sitting/idling not accelerating.

HONKEYMAN do you experience any surging while idling (like the idle goes up and down constantly)?

yea exactly, it will surge like its gonna die, and then sometimes level at around 1000 and hold steady, but if i pull up a little bit slowly and then come to another stop, it will do the same thing-surge a couple times and then level off. Does this help any?

ok I believe your problem to be your Idle Air Control Valve (IAC). I have a similar problem, in the morning when I first start it. it used to just shutoff after I start it - would start then die immediately, I would have to hold the gas pedal down for about a minute before it would idle w/out stalling, I replaced the IAC about a month ago, I had the same problem for a couple days and now it starts then drops to about 200rpms then back up and down, etc. like your is doing.
I also replaced my TPS at the same time - I tested it when I first got it, and the new one is not where it should be (at wide-open throttle should read 4.5 volts, my old one read 3.77 volts and the new one reads 3.85 volts) so I think I am gonna have to get another one, I bought it from Autozone (WELLS brand) and they are know to be bad out of the box, so I think I need to go elsewhere and buy another IAC and TPS.

altho I know the IAC is whats causing my problem.

you may want to test the Throttle Position Sensor, if you need instructions, email me.

Joe
dksob81@hotmail.com

thanks, i found a site while searching for parts www.rockauto.com, and you might want to get parts there, it looks really cheap.