Mark VIII idle problem HELP!!

[97B&BLSC]

Hello guys I`m new here on LVC I own a 97 Mark VIII LSC I have been having troubles with the engines idle speed the car would start fine work fine for a while and all of the sudden it wouldn’t rev down to regular idle speed (around 750 to 800rpm I think) it would stay at 1200rpm on drive if I shift in to Neutral or Park goes up to 3500rpm I have to shut the engine down for a few seconds and start it back up for the engine to go back to normal idle speed I change the TPS sensor 3 times thinking it was defective but so far no luck has anyone had an issue like this one? Please help!!!!!

Thanks

 

[opalescent 96]

Welcome to the forum!

I believe that would be your idle air control valve(iac). Change it for a new Motorcraft replacement and you're good to go!

 

[chris2523]

yeah i would try the IAC.
luckily its very easy to get to on a 97.

 

[jbelcourt]

yeah i would try the IAC.
luckily its very easy to get to on a 97.

I third that. IAC valve is probably your best bet. Also, be grateful it's not a Gen 1...trust me.

Motorcraft or BWD are your best bets. DO NOT buy the cheap ones....they tend to "whistle" among other issues.

 

[ONLYTONY]

It's that shiney thing right on top, and don't forget a new gasket

 

[BigPip]

Edit- my post is so unrelated, sorry-

 

[slowmkviii]

I personally would pull the IAC off and clean it before getting a new one. Still need new gasket though.

And yes I have successfully cleaned 3 for my own marks 2 gen 1s and a gen 2.
The gen 1s I cleaned them without taking them out of the car.