93 cherokee running rough

1993 cherokee 4x4 4.0
just started friday night after off roading in the am.
runs rough at startup even when you gas it, gets much better when warm, but will miss sometimes on highway speeds with little gas, clears up when you gas it. does it even after sitting for 10 minutes!
IAC, throttle body clean, cap rotor wires good, pump risestor ok, replaced fuel filter! vacume hoses look good. no check engine light.
please help, I love this car, :confused:

hm, well check the wiring specifically the 02 sensor, also check your spark plugs and see what they look like, make sure none of them are starting to foul. If all that seems ok, check the EGR system.

hm, well check the wiring specifically the 02 sensor, also check your spark plugs and see what they look like, make sure none of them are starting to foul. If all that seems ok, check the EGR system.
I must be blind, but I am having a time trying to locate the egr valve, I will check the o2 monday, thanks for your reply

Scuba4321, You might want to check your fuel pressure to make sure your pump is putting out enought p.s.i. Also check your Throttle positioning sensor, one way of doing this is unconnecting the part to see if it runs the same or different.

:biggrin:

Did you get water in your gas tank for any reason. Throw some injector cleaner in the tank.
How is your fuel and air filter?
Is it leaking anything?
Check for unplugged wire, o2 sensor damaged?

dima4855

update,

o2 sensor, coolant temp, crank position, map sensor, idle speed motor, cap, rotor, wires are all good, i pulled the iac apart and cleaned it, unsure if it is working, i unplugged it while running nothing changed,
question....would the iac have anything to do with anything other than idle? i am having problems even at speed.

all filters good, tried fuels additive, no water in cap n rotor.
I can not find the EGR valve to save my life, that and plugs are my last hope!! :mad: :mad:

you could check your coil?
IAC - idle air control valve is An electrically operated valve which allows air to bypass the throttle plate in a fuel injected engine to regulate engine idle speed. Also, kind of works as choke when the engine is cold.

try unplugging the MAP sensor and see if there is any difference. the same thing with the tps.
will look on my jeep and try to describe where the egr is

just pulled all 6 plugs, 1 off them the insulator at the tip was cracked verticaly, i pulled the piece right off, also the were gapped.o45 instead off .035.
will replace all 6 today, cross my fingers

just replaced to plugs and she purrs like a kitten......$1.59.......these motors are rock solid
171,500 miles and still is an awsome off road suv