EEVEE

*face desks* My jeep is being bad. Ok short sweet and to the point. I was pulling out of my friends house and i went to tap the gas pedal like normal and my jeep took off on me backwards. Thank god it stopped, so im like why are you doing this so i pull back in and sure enough took off a bit again, i stuck it in neutral and seemed normal till i tapped the gas pedal and it revved like normal going up but going down it hung there for a good second before slowly going back down to normal. Great i guess i got a vacuum leak somewhere so i went to check the codes and there was 5 codes that came back but cant remember the numbers (joy ill explain some)

Code 1: Idle air control valve (This one i caused as i cleaned the unit as it was filthy and put it back together and like the dimwitted moron i am forgot to plug it back in so theres that code)

Code 2: Coolant temp sensor (i unplugged this to check the cooling fan to no success)

Code 3: Evaporator purge valve thing (this was a new one but am not gonna bother fixing till later)

Code 4: Coolant temp sensor (again unplugged it then voila the fan worked yay break out the beer and confetti)

Code 5: Idle air control valve (this one i think is new i dont remember this at all plus why does it duplicate codes?)

Anyways thats where i am right now, On the computer writing this currently as im waiting about 30 mins with the battery unhooked to reset the computer on the jeep and i am gonna swap the iac to see if this fixes the issue. I just hope this iac works this guy was selling his jeep and gave me a bag full of jeep goodies (Yay!) which was a set of spark plug wires with unknown condition, tons of fluids, a spark plug and you guessed it an idle air control valve. Looks fairly clean so maybe it is new? Nothing came off on my fingers when i touched the valve part thats on the spring, Thats why im assuming its maybe new or newer that was slightly used. Im waiting for the engine to cool off to start replacing that valve and maybe clean the throttle body while im at it as its been pouring rain and as it sat for a day. I went to start it up and it had a very hard time starting and coughed through the throttle body and sputtered to life. Maybe that cough broke the valve?

EEVEE

Update: I just took it to get the codes checked again after disconnecting the battery and only the evap code popped up again but nothing else. So what now? i am stumped.

nujeepguy

cant be sticking somewhere?

EEVEE

thats what i initially thought but i moved the throttle by hand on the throttle body and it still did it. also just slightly tapping it open like i mean a slight enough to make it rev by a hair makes it hang. so no its not sticking i changed the iac and that didnt help... tho improved my idle by a bit it still hangs. no codes or even anything i can go by to track it down. ill post a video shortly here.

EEVEE

https://www.youtube.com/watch?v=OLjb...ature=youtu.be

EEVEE

To be honest i wouldnt mind it doing it in neutral but its very annoying backing up and tapping the gas pedal (petal or pedal? lol) and having it take off then jamming on the brakes.

EEVEE

crap... wrong setting lol heres another link just incase: https://www.youtube.com/watch?v=OLjb...ature=youtu.be

EEVEE

also i plugged the vacuum port to make sure there wasnt a leak but it still did it. could it be a throttle position sensor?

XJeepCheep

It could be a lot of things, maybe even just a dirty throttle body sticking open a hair.
I recently had it happen to me and I found a vacuum leak at the cruse and it fixed it.

EEVEE

would disconnecting the vacuum hose to test for a leak a good way to find if a leak is the issue? i took off that 90 degree boot and plugged it to test it and it did the same exact thing. i searched high and low and only found 4 forums on this and they werent solved or explained how it was fixed. what would be the common issues so i can run down the list and test each and every one of the problems? im most likely gonna clean the throttle body to double check. also if i did check the vacuum system just take a cigarette and blow smoke through the hose? and if so which hose? this is already driving me crazy, i hate how it keeps going forward or backwards when i let off the gas. also thanks for the input lol i been checking like mad for possible solutions.

XJeepCheep

what year is it?

EEVEE

1999

XJeepCheep

No codes?
how high is the idle? ( when it hangs)
if you rev it to 2-3 grand what does it settle at?
When you first start it does it idle normal?

EEVEE

no codes and i cant really remember its anytime i hit the gas it hangs randomly. i can get a video showing everything it does just tell me what to do.

EEVEE

i think its time to change my cat though everytime i shut it off i hear like a muffled exhaust sound so maybe my cat is clogged? i cant afford to replace it at the moment but i was planning to change it soon along with my entire system.