96 cherokee will not idle

[cowpoo]

Originally Posted by Rodgebone

i would think if the dizzy was that bad it would have set a misfire code but you say there are no codes...how much rotational play is in the dizzy (measure it at the rotor and i can compare to mine for you)...it would also be good to pull the dizzy out and look at the gear on the end of the shaft and check it for wear....also look at the cap and check for tracking (trace lines between the lugs)

before buying anything else....if it were me id also like to know fuel pressures, spark plug/leads condition/brand/gap, battery condition, air filter condition, coil condition and then maybe checking fuel pump and TP voltages (this SHOULD set a code but i spoze anything is possible)....what did the idle air bypass pintle look like? did it have a lot of carbon/sludge on it? did it move freely? im assuming you still have no codes

one backyard mechanic test you can do as well is let it idle and start tapping on different sensors with a wrench (or something) and see if it dies....if it does check for a poor connection to that sensor

i know its a lot to look at but could be anything from your description - just remember you need air/fuel, spark and compression to run a motor

is the idle air bypass on the rockercover /firewall side of the TB ? if so it was covered in carbon and didnt move freely

[Gojeep]

The idle bypass is part of the throttle body.

[Rodgebone]

the iac is part of the throttle body and is located on the rocker cover side of the tb...if is was carbon sludged this is prolly yer problem...a bit of carbon prevents it from closing fully or makes it stick and sets off chaos within the computuer's idle inputs (the iac and tps being the most important)...it makes the computer think you have the throttle as just above open idle (like putting yer foot on it when the light turns green as opposed to a full stop)...clean that sucker thoroughly with throttle body cleaner...remove it and soak it in a container overnight (or two nights) and if most of the gunk is still there replace it

[Snapey]

OK, I'm not into fuel injection or the technical side of it all - far too mant TLAs for my liking. (Three Letter Aconyms).

I did have an idle problem a couple of years ago. I would start the car and it simply wouldn't idle. Even if I sat there with my foot on the throttle to provide idle speed and let it warm up, as soon as I took my foot of it would die. No cough or splutter - it just stopped dead. It made Sydney traffic very interesting I can tell you! Someone I spoke to said it could be the idle solenoid sticking. Now I don't even know if it's got one, but a tap with the handle end of a hammer to the throttle body and surrounds fixed the problem instantly. It has happened again a couple of times since and each time a few well placed taps fixes the problem. Pretty low tech I know - but hey, it worked.

[Wooders]

"No codes" - How did you check them?
Probably a good idea to get a dealership to plug in their DRB reader rather than just replacing sensor after sensor

[Rodgebone]

agaiin sounds like sludge (carbon buildup on the throttle).clean the trottle body and IAC

[brizXJ]

Cowpoo..you mentioned that you replaced both O2 sensors...can I ask where you got that and how much were they?