I bought my 88 Jeep Cherokee 4.0 4 months ago as is ran fine and didnt notice any problems. A week later as I was driving down the highway at 55 to 60 it started to buck on me, when I got into town it died on me and would start back up. When you put it in Neutral it stay running. Ive asked a few of my buddy who own Cherokees and they are not sure if its the MAP Sensor, TPS Sensor, Cransaft Sensor or if my Torque Converstor is going out. Can someone please help me pinpoint the problem. Thanks

It does have 271,000 miles on it.

 

I had a similar issue (87 cherokee laredo 4.0) and it was because my alternator was dying. When it died it took my starter with it somehow. Also fuel filter clog could cause something like that.

 

The first thing I would test for is good fuel pressure at the Fuel injection rail test port. You will need a hand held pressure gauge for this. Should be 30 PSI with the motor idling. Anything else and your Fuel Pump is bad or going bad. If it reads 30 PSI then, pull the vacuum line off the Fuel Pressure Regulator at the forward end of the fuel injection rail. The Pressure should jump up to 39 PSI. If this reading is wrong then your Fuel Pressure Regulator is bad.

 

OK thanks for the info I will go and check it out!

 

Most likely a fuel pump but check the pressure at the rail before you take the tank out that way you didnt waste time and money replacing the pump if it's not the problem.....

 

Last time I had symptoms like this turned out to be the MAP sensor...Try unplugging that and see what happens

 

I replaced the TPS Sensor yesterday and it seems to run better but when its idling it acts like it wants to die then it will go back to running fine. Thats what I think its got something to do with the Fuel pump or something fuel related. Im going to look into the MAP Sensor since thats the last thing thats on my check list before the Torque Converstor. Thanks guys for all of your help I will keep you all posted. Im new to owning Jeeps and learning everyday. I own 3 of them now lol.

 

I had a bad fuel line at the fuel pump. Some days it would work fine and then others I was embarrassed to drive it. I would check the fuel pump before I bought anything. Does it backfire through the throttlebody.

 

No it doesnt backfire through the throttlebody. I also have noticed that it turns over longer than I think it should tho and then it does fire. I believe that its a Fuel issue. Im going to go work on it this weekend and will keep you guys posted. Thanks for all of the help.

 

I want to thank you guys for your help! I put the new TPS Sensor in and then drove it and it doesnt buck or die at stop lights. Im going to be putting a 3 to 4 inch lift on it soon and hope to have fun with it Thanks alot XJ kid

 

my 95 did the same thing on me.. used to kick and die.. especially at idle or on the highway.. new tps sensor and it runs like a champ at 186k... GL with it