WolfeMan

Sorry. Don't know the proper terms to do more research.

Tried to start my jeep the other day no more than an hour after I had been driving it and it wouldn't run. Turned over but wasn't starting. It felt "choked" almost so I removed this tube from the engine and it started right up but it idles high so I guess it regulates air flow. The only reason I even thought to try it was because once when I got it back from the mechanic and I noticed it was idling high and found that tube disconnected so I put it back in and no more high idle.

Here's a pic of the thing where the tube connects. I'm sure you experienced guys will know what it is:


Seems like it should be easy to fix but I'm not sure where to start. Any recommendations are greatly appreciated. Thanks in advance!

dans98xj

I would look at giving your throttle body a good cleaning. If the only way your jeep will idle is to have a major vacuum leak then your IAC is gummed up pretty bad or not working at all. That line you took off is for your brake booster. You will not have power brakes with that removed.

TwistedWrench

X2

The IAC(idle air control valve) does exactly what it's name implies. At idle, your throttle blade is actually completely shut, and the valve opens allowing just enough air through to maintain idle. When this part craps out, you get this exact problem.

Quick way to verify; plug your vac. line back in, and start the engine while holding the gas pedal slightly down. It should start, then stumble and/or die when you release the gas.

Fix this properly, do NOT attempt to adjust or modify the throttle position. This will throw off the TPS, causing the jeep to run rich, and cause rapid wear to automatic transmissions.