Fast idle cause ideas

[XR7Kurt]

I did the search and of course it's between a bad IAC selonoid and vacuum leak. But you guys always help me out the best so here it is:
All of a sudden last night the idle jumps up to 2,000rpm as I'm driving home it sometimes drops to 1500. As I'm driving I can hear a whistleing noise.
Back home, checking under the hood I don't hear anything except a humming from the air intake box(filter). No obvious vacuum leaks.
Today on first start it goes to 2,000 but then drops to 1500 then 1000. Driving around it would hang around 1000-1500 mostly 1000.
Still has the whistle today and when I turn it off it makes a wierd groaning sound, possibly just the whistle winding down quickly.

My thoughts are that if it was a vacuum leak it would not have dropped from yesterday and also would not have dropped after I first started. When I started it could it was as it it followed the normal short warm-up fast idle only at a higher range.
My question is if I pull the wire to the IAC thingy and it idles the same does this mean that it is not the IAC deal?

Kurt

[onequiksc]

That's verbatim on when mine went in the mid 90's Kurt. IAC.

[Sweet90SC]

I dunno what a IAC is :rolleyes: ...............buuuuuuuuutttt..... when I had vaccum leaks the darn thing cycled up and down in RPMs revving up then down over and over

[XR7Kurt]

How 'bout that, a split decision. :rolleyes: I guess I'll order the IAC and then keep looking for vacuum leaks until it comes in.
Anyone know about what should happen when you disconnect the IAC? I'm guessing it must fail open.

Kurt

[onequiksc]

This thread may help you find those answers Kurt;

http://www.sccoa.com/forums/showthread.php?t=57962&highlight=IAC

[Sweet90SC]

I still don't know what a IAC is..... :confused:

[onequiksc]

I still don't know what a IAC is..... :confused:
Rick...Idle Air Control; it controls air around the throttle plates to compensate for engine load etc. and maintain a steady idle.

It looks a little like an accordion when you remove it.

[XR7Kurt]

O.K., one more question on this subject. I was able to get the part today for $88. Once it was in my hand I realized it might need a gasket. The Ford parts guy said you usually use the old one. Is this likely?

On a side note; after I make my last stop before heading to the bank and then the dealer, this crazy thing started idling normal and has continued to due so all evening since I picked up the part. :p

Kurt

[onequiksc]

I'm not sure a about the gasket Kurt, but you haven't much to lose in giving the old one a shot I suppose.

Weird about the symptoms going away, but my way of thinking says it's more likely the IAC is in /out ( and on it's way out permanently eventually) rather than a vacuum leak suddenly solving itself.

But then, cars are strange. :confused:

[XR7Kurt]

Yeah, I don't really like troubleshooting buy replacing parts, but I figured this one will go eventually anyhow. Same thoughts as you on the vacuum correcting itself.

Kurt

[Sweet90SC]

But then, cars are strange. :confused:

"Momma!" "Cars don't behave, they are behaved upon." Dan Akroyd "Driving Miss Daisey"

[Gregthespy]

well, from what I've heard is that the strange goose like noise or groaning when you shut it off is in fact the IAC valve gone bad. As far as the gasket, I don't believe you can buy just that gasket but more of a "throttle body gasket pack" which includes all the throttle body gaskets. You probably could get away with just using the old one but if that doesn't work and you can't find a new one I'd just get some paper gasket material from any parts store and trace the reminants of the old one, cut it out and use that. It doesn't sound too much like a vac leak with it just going away some times, sounds like something getting stuck intermitantly.
Hope this helps...

[Sweet90SC]

I don't see it???????? Where is it??????? :confused:

[XR7Kurt]

from what I've heard is that the strange goose like noise or groaning when you shut it off is in fact the IAC valve gone bad.
I forgot to mention even though the idle was better, I still had the noise although not as prominent.

Here it is Rick. Installed It's on the side of the throttle body, pretty much blends in with all the other black stuff jammed in there. The electrical plug goes on top.

[Sweet90SC]

I forgot to mention even though the idle was better, I still had the noise although not as prominent.

Here it is Rick. Installed It's on the side of the throttle body, pretty much blends in with all the other black stuff jammed in there. The electrical plug goes on top.


OOOOOOOHHH!!!! That thingy thing on there ok I got it now.....Yea I have one of those. Mine says SVT on it though:D

[Jake]

Kurt I reused my old gasket b/c it looked new. There is no oil, water, any fluid at all around it so the gasket should look fine. Just check it for cracks.

[XR7Kurt]

THE GOOSE IS DEAD!! :D $88. Thanks for the help guys.

Kurt

[Sweet90SC]

THE GOOSE IS DEAD!! :D kurt

Yea his head hit the canopy when he ejected with Maverick...terribly sad I cried all night.. :(

[XR7Kurt]

You never close your eyes......

Kurt

[victor malvar]

Here ya go Kurt, What size is you throttle body? If it's a 75mm the currect could be staying on and not shuting off. This is being looked into at this time by BBK. The other is these things fill up with carbon and you can clean them they will run a little while but eventually you will need a new one...the other might be your butterfly on the TB may be sticking and staying open, causing you to idle higher. Try slipping a piece of paper/ folded in half and see it it slides threw the butterfly on the TB easily or real loose. Your fuel pressure could be weak or surging, try to see if your fuel filter is clean...whistling sound could also be some sort of a sucking sound like a craked vacum hose of some type of pressure realesing what side of the engine do you hear if on? You do need a gasket for the IAC and Greg is right. If your engine has a few miles on it play it safe and if you need a gasket I have them. I could mail you one or make you one from gasket paper material it's not expensive don't do a half --- job. If this does not help? I will help you get it corrected. I can loan you used parts that work and when you've diagnosed it just pay for what you need.
Good luck!
Victor.....
Also check that plenum to intake is not craked the one behind the Blower with the 3 bolts that hold it down. They brake sometimes and it's hell trying to find where the vacum leak is they will crack at the bottom bolts, Might as well make sure you intake is on the TB nicely on tight. I'm tired! I have left a bunch of replys and I have to take care of My brother now.
call me if you need my help? Check to make sure there no sucking sound around your I/C tubes how are you mor tor mounts? No Overheating or bubles in you reservoir right. Radiator reservoir.
352-732-5013
Victor

[XR7Kurt]

Thanks Victor but it was my IAC valve. I fixed it about a week before I found out I needed that balancer. $96 from Ford, I saw last night you have them about $30 cheaper. I don't think you had them yet when I needed mine. Oh well, you can't have everything, YET!
I meant to let you know my balancer did come quickly once UPS decided to ship it. :D
I'll be calling you soon when I decide how far I'm going to go on this while it's apart.

Thanks again,

Kurt