Won't idle down with clutch engaged

[pennman93]

My 2000 SVTC is having problems dropping rpm's with clutch engaged. It has happened before, but went away. It has come back and bugs the hell out of me. When I push the clutch in, the engine rev's a little higher then drops back to what it was when I engaged the clutch. After 4-6 seconds with the clutch still pushed in it will drop rpm's. Please help. :shrug: :shrug:

 

[Ryan]

clean/replace the IAC and go from there...

 

[black99lightnin]

clean/replace the IAC and go from there...

Agreed, or just spend the $50 and buy a new one.

 

[Y2KSVT]

What does the IAC have to do with the clutch being pressed in though? I've got a similar issue with my SVT. The throttle will hang at ~1500rpms until I press the clutch pedal in, where it goes back to it's normal 750rpms. How are the clutch and the IAC related in this sense?

Mark

 

[Ryan]

I believe its due to vacuum, but not 100% sure on the technicalities. IIRC, the car will idle a bit 'high' when cold to for warm up / emissions reasons then will drop back down to a 'normal' idle.

 

[pennman93]

What does the IAC have to do with the clutch being pressed in though? I've got a similar issue with my SVT. The throttle will hang at ~1500rpms until I press the clutch pedal in, where it goes back to it's normal 750rpms. How are the clutch and the IAC related in this sense?

My rpm's will not drop when shifting. When I shift the rpm's will rise until I'm in gear, or if I hold the clutch in will rolling, it will drop, but not for several seconds. I ordered an IAC, to see if that is the problem. Hopefully it works. I have 103k on the clutch, and drive it like I stole it. I am worried that this will cause me to have problems with a clutch that has probably going to go out soon.

 

[WhatV8]

The EEC is programmed to not let the rpm's drop right away to help aid in shifting, so your rpm's don't drop below the next gear's point. If you take your car out of gear while moving the idle will only drop to ~1000rpm. Once you get below ~5mph the idle will drop all the way down to the base idle of ~750rpm...this is completely normal.

If your rpm goes up when you depress the clutch and it holds it, that would likely be a sticking IAC. Take it off, soak it with brake cleaner for 20-30 minutes and rinse.

The link between rpm and the clutch being depressed is ENGINE LOAD. This is all in reference to a car sitting still. Say if you have very cold tranny fluid the engine will see the load of the input shaft in the 'heavy' fluid and raise the idle to compensate, just like when your A/C compressor cycles. When you push in the clutch the load will be removed from the engine and it will come down to its 'normal' low idle. HTH.

 

[pennman93]

Put the Ford IAC in today. Worked perfect! Thanks for the help guys. When I shift the rpm's stay at what I shift at, they do not raise 500-700 rpm any more. Thank you for the help. For those that have idleing problems, change the IAC!!!