93 cherokee 2dr w/126k

problem: wont idle and stalls. when it does stall it'll crank up after the 2nd turn

PO installed new plugs, wires, tires, cap, rotor, tires.

After reading and reading I narrowed it down to the CPS and TPS. Off to the shop to replaced said parts (bad move I know)

After replacing said parts the jeep ran the SAME (DAMN) so the shop puts the old parts back on and start to troubleshoot the jeep. FOUR hours later the mgr says theres nothing machanically wrong, so it must be electrical. There are no codes, no vaccum leaks, and good spark....

He says it might be the computer but wants me to leave the truck. Also the computer installed gonna run about $400-500.

I would really hate to drop $500 in a $1300 investment. On top of the $500 Ive already spent doing breaks, injector service, and exhaust installed, oil change, air filter and radiator flushing.

I only drive this truck 5-6 times a year for 5-10 days at a time when im in NYC on business.. Its a great truck for the horrible NYC streets


HELP, I love the truck but I cant keep driving it like this and with 128k on the clock the damn thing is has plenty life left.....

 

Check fuel pressure?

 

Have you tested and adjusted the tps? It isn't a hard procedure.

 

I guess they did, I dunno.. I guess I can take it back and have them look @ it, but hell you'd think they would but I didnt know enough to ask...


could it be a defective part? I didnt know it was adjustable.


Im pissed b/c my time is so limited while in New York I dont have time to do the little I know (im NO wrencher) and I know it something small

 

Fuel pump may be on its way out if it doesnt idle correctly and stall. It wont throw a code because it technically is still work but slowly failing. If you have backfire or loss of power while acceleration Im gonna say its the fuel pump. Its pretty easy to check, just throw a pressure gauge on the fuel rail. Should be around 49PSI I think. Also the TPS is adjustable and can be checked with a multimeter. to adjust it you loosen the 2 hex screws on the side and move it up and down to adjust it.

 

TPS is only adjustable on Renix (87-90)
TPS is non-adjustable on HO (91-01)

 

Oh I didn't know that, I guess im wrong then. I learn something new everyday.

 

You could try cleaning up the idle air control...

 

Oops...91 and later is non adjustable. You can test it however. Leave the connector hooked up and stick the positive probe.into the back of he connector on the center wire and the negative I'm the back of the connector on the black wire. Set multi meter 20volt dc. Turn your ignition to on but don't start. Closed should read greater then 200 millivolts slowly open the throttle to wide open. It should transition up to a little less then 4.8 volts. If the readings are off replace.

 

Voltages on post RENIX TPS are different. My '96 voltages were 5.1v input, .76 output with throttle closed and 3.8v throttle wide open. Ideally, an anlog meter should be used so as to very a smooth sweep increase in voltage.

 

Anyone thought of checking the MAP sensor? that was the problem on my 01 xj when i thought it was the tps. caused the same problems.