View Full Version : 2002 N* Deville occasionally idles too high


cheeko
02-05-07, 01:57 PM
I recently purchased a fine 2002 Deville with N* of course.(135,000miles) It had some bad oil leaks so I had a mechanic pull the engine and seal it all up. Since then it does not appear to leak oil but it has been occasionally idling very high (1350at times) When in drive at stop lights it just wants to go and this high idle causes it to shift into R and D hard. Most times it idles perfect. When it is idling high, I can usually shut the car off and wait a sec then start it back up and seems to idle fine again for a while. I have not tried the carb cleaner spray on hoses or intake, trick yet. Also, in the morning it has had trouble starting sometimes. I would try it several times and no go. Then I decided to give it a little throttle at startup and it started right up and I noticed a gasoline smell. It has been very cold weather here lately (0's) if it has anything to do with it. The first time this high idle thing happened, the service engine soon light came on after I noticed it was running poorly. This was just after the engine oil fix so I brought it back to the mech. and he read the codes. There were two of them. It said high idle and something else. He also said that those codes were in the history so he cleared them and then told me to come back again when the light comes back on. He also pulled the vacuum hose from the fuel pressure regulator? for 15 min. and it never leaked fuel. It's been a week since then and no lights have come on yet but the high idle problem has occurred several times. It has been starting up fine lately also. Any help would be greatly appreciated !! :worship: :bonkers:

eldorado1
02-05-07, 02:56 PM
There is a rubber hose that connects your plastic intake to your metal throttle body (actually the water crossover housing). I've read a few threads here where people have had them crack and leak. I'd probably start there.

Ranger
02-05-07, 05:27 PM
It also might not hurt to clean the TB (Throttle Body) and IAC (Idle Air Control) valve.

ewill3rd
02-05-07, 08:18 PM
I would follow Ranger's advice and if you still have problems, replace the Idle Air Control valve. I have seen them get sticky and bind periodically.
I went round and round with one for 6 months before I caught it acting up.