XJ_SPORT

im having problems with acceleration, when i press the throttle around 1/4 of the way it starts to accelerate and will run and drive good, when i get into it about 1/2 to full throttle it starts hesitate or stumble and trys to die, it does not like to idle when ac is on (starts to idle at 400-600rpm) sometimes dies, i know its not my injectors, spark plugs, distributer cap and rotor, plug wires, fuel filter, airfilter, TPS, coil, distributer, or an air leak on my intake manifold just replaced the gasket for the intake and exhaust(problem was there before i replaced all of those items), not compression they are all pretty much even from 130 to 140 psi, its a 1989 jeep cherokee, engine has 145,000 miles on it and its the 4.0l I6

mike albo

try cleaning your IAC sensor, also check your MAP sensor

XJ_SPORT

sorry forgot to mention that i cleaned everything on my intake including the IAC, so its not stuck, leaking or anyhting, how do you test the map sensor

XJ_SPORT

could it be my crank position sensor?

mike albo

Maybe on he CPS,as far as test ing the map sensor I can't find my big book that discribes how to.You can pick up a repair manual pretty cheap at an auto parts store though.I will keep looking for it though.

XJ_SPORT

i have a haynes manual, found out how to check it with a volt meter, can seem to find where you would go to check the CPS

mike albo

found mine to check the CPS by disconect from the harness test across terminal A and B Resistence should be at 125-275omhs with a hot engine

XJ_SPORT

what page is it on or what section is it in

mike albo

I have the Chiltons manual it was in the tune-up and performance section

XJ_SPORT

cool i have one of those too thanks

md1032

hey i have an 89 cherokee. ok i had a similar problem. what fixed mine was the little vacuum fuel valve thing in the very front of the fuel rail thats connected to all the injectors.

could it be that