strange Idle

just be sure to get one from your ford dealer,no aftermarket

I have had the problem but for me it was a small vaccum leak, there was a hole in one of the hoses and when the car warmed up the idle smoothed out. But in reading it I think it is also your IAC, I'm tempted to try it on my car since it is doing it, the previous owner replaced the IAC before I purchased it.

My car is kind of doing that now again too, except the RPM's go to roughly 1500 and dont come back down, but that might just be the weather, plus my buddy works at the local Ford dealer know-Parts at cost FTMFW!

Apparently some of the 99-00 GTs had a computer update. If your PCM cannot learn the fuel trims, it can cause the problems you describe. I would take it to the dealer and have them check the computer to see if it's updated. If you have replaced the IAC,PCV/grommet,IAT,plugs,vac lines,MAF,TPS,fuel filter- there is not much more you can do lol. At that point I would take it to a shop/dealer.

what is the sensor behind the MAF?

I was cleaning out a few hting on my car today and i popped it out and sprayed it down like i did my MAF a while back and guess what...

My damn idle started acting up again.....
there are 2 things i can think of now that could cause the racing idle when clutch is pressed down or in neutral that we havent tried yet.
1. the sensor on the inlet tube right behind the MAF
2. perhaps my intake tube is bouncing around messing with the MAF sensor in some way ( i have the C&L Intake kit and it kinda just free floats, only be held down by the plastic cover.)

I had the exact same symptoms as the OP describes in his initial post. After searching stangnet for ~5 minutes and ending up here, spending ~$48.50 on the Wells IAC (love sales tax, not), and performing a 10 minute install (had a false start putting the replacement on due to poor available selection of tools), I no longer have any symptoms.

That includes the search that found me the image in the plenum/TB walk through which has the EGR/IAC/TPS circled, since I didn't know my IAC from my TPS before yesterday.

I luv da interweb!

:SNSign:


It is nice to have a car that works right again, especially after fixing it myself.

Just wanted to share.

I've heard that there are only 5 Ford Master Techs east of the mississippi. Who are certified in everything. My uncle is one of them. He has found and fixed all my problems( IAC, fuel pump, trans, and rear end). During our IAC discussion I was told this.... Your mass air heats up and reads the air temp coming in your intake, this relays info to your IAC to idle your car properly, the IAC transfers info to the TPS to what is going on for when the tps asks for more throttle the mass air relates incoming air speed,temp, and ask for more fuel and the IAC to open more.

From what he says the mass air is in control from the start. My car does the same idling high low when rolling also. He told me the air volume coming in while rolling is asking for fuel till the air stops when I stop and my car idles down. I've had it for 5 years and this has happened for 5 years. ALSO this is gonna sound stupid but check your pedal to carpet clearance. My pedal got stuck at about 3,800 rpm and I thought it was the IAC. I unplugged it and my car went to 500 rpm later to find out my pedal was stuck under the carpet..... You might have a problem that won't show up on your ses light for a while. Ford computers are constantly checking and rechecking everything while driving. For your computer to run a full check on everything it will take about 4 hours of constant driving.

I've also looked at a tremec3650 problem thread but its like 50 pages..... Ford has a fix for the 1st to 2nd cold grind. They have a kit that is about ohhhh 900.00 that is supposed to fix all the bugs with that tranny.

I killed mine till I got a descent shifter....B&M

WillieMakeIt said:

My pedal got stuck at about 3,800 rpm and I thought it was the IAC. I unplugged it and my car went to 500 rpm later to find out my pedal was stuck under the carpet.....

Click to expand...

Shortly after I got my car (a couple weeks, at most), I modded it to raise the level of the gas pedal to be much closer to the height of the brake pedal. Makes reaching both with the same foot at the same time much easier. It gets no where near the carpet, since then.

It would be wonderful to have a resource like your uncle in the family to help with the inevitable issues. You're very lucky. Still, I use the internet to help me get the simple things, like this repair and my lowering springs install, done on my own. It is better than nothing, by far.

My father had nothing like the internet when he was building his Bonneville before I was born. My mom has told me he used to just bring over the pieces he had left over to a local autoshop (after an engine rebuild or something), and they would tell him what they were. He could then figure out where he went wrong.

- whoops, hit Quote instead of Edit

Hey stangman16, did that new TPS fix your problem...my 98 cobra has the same issues, and I installed a new IAC a month ago. Thanks.