So I noticed my jeep decided to start idling terrible, but it only does it once in a while. I have replaced the tps and cleaned the iac, as well as cleaned all the engine grounds. The engine is also running ungodly rich. It had codes but I had them erased and they have not popped back up. So what is going on?

Here is a video of it crapping out on me

 

did you do the basics yet, plugs for start???????also what were the codes???????

 

The spark plugs look in great shape (a little dirty from running rich), The other weird thing is that it does it inconsistently and at any temp or altitude, and there are no codes now (it had 4 o2 sensor codes 3 for the fromt and one for the rear and a code for the tps but thats because I replaced it and did not erase the codes)

 

i would consider changing the plugs if they have been subject to excessive fuel .as a place to start....why was the tps changed??????

 

mine was fixed with a new fuel filter. Probly needs a new one anyway.

 

The tps tested faulty at anything past 1/2 throttle so it was bad. I also do not think it is the spark plugs as it does this at any temp, and only at idle. At 1100 rpm it smooths out perfect, still rich but perfect.

 

I would if i could but that still would not explain the issue at hand.

 

did you test the new tps and spark plugs will be affected by fuel saturation causing them not to fire at low rpms its a quick test that should not be over looked because they look ok,start simple ,dont over think things ,also when was the last time you cleaned the injectors with a in tank additive ???????

 

My jeep has in its lifetime had the same problem twice. It got so bad that i used to have to put it in neutral at stop lights and give it throttle to stay running.

First time was a couple years ago: After 6 months of the problem, I finally (don't ask me why) just gave it a ton of coolant (way more than i thought it needed) and the problem went away.

Second time was a few months ago: I switched to premium gas and only buy gas from good stations that don't look sketchy. Problems gone.

I assume its magic.

 

I really appreciate all the input, but as i said I checked the plugs and tps and iac and coolant and all the main wiring. It only does this at idle and not at any other rpm. It is running rich and I am certain that the fuel is not to blame, as well as the plugs. If the thing does it in the morining I will just go to the stealership and have them work on it.

also I know it has a bit of a power loss as i am a rather... agressive... driver. my carpet has an indentation were the gas pedal stops.

 

Gotta wonder about that O2 sensor. It DOES control the mixture. You did at one time get a code. The only other sensor I've changed on my 90 in 10 years was the CPS. Also I guess it's nice to know the O2 is right for mileage. So theres that. Good luck.

I think the front one does the mixture and the rear is for operation of the cat
Saw this in the "XJ 5 speed swap" thread :
" if that happens, it will run rich. if that happens, it will either keep wrecking 02 sensors, "

 

Check your iac aswell

 

Have you done a compression test?

 

have you checked the map sensor up on the fire wall, if it is bad you have the same problem you are describing or it won't run at all.

 

dont want to sound silly here.....

sounds like an injector failing.

throttle up fuel is delivered ok, min throttle,, fuel is being dumped probably by a sticky injector....

just my opinion sir, might wanna check them (i.e. remove each one independently, maybe buy one as a spare, put that in place successively and see if anything changes on each swap)

I wish you luck but thats what it sounds like to me from what I am reading.

cpnwrench