High idle and slight hesatation when cold, Getting Tired Of This

[ubnpast]

I am getting really tired of this priblem, I dont have any cel's. I have cleaned the tb which wasnt too bad to begin with.
I removed the IAC and cleaned it twice.

Now I dont believe I have the same problem as others because when my car is rolling the rpms stay at 1500, only after I come to a stop they down after 8-10 seconds or so. So if I come to a stop at a traffic light wait about 8-10 the rpms will slowly drop down to 650, now if I roll foward such as if I was on a hill the rpms would go back up a little again.

I have the Mr. Moose bag pipe, I tried the throttle hang fix, I had to put the cap in the hose after the intake, but before the "bag" I assume its called, look at pic:

I have a 96 5 speed mystique, anything else I can try or clues to as what I can check?

 

[Tony2005]

Maybe time for a new Ford IAC valve.

 

[ubnpast]

Maybe time for a new Ford IAC valve.

But will the high idle only while rolling be caused by this?

 

[ubnpast]

Could the tps also cause this?

 

[Tony2005]

But will the high idle only while rolling be caused by this?

Rolling is idling.

Could the tps also cause this?

Yes.

 

[ubnpast]

Rolling is idling.



Yes.

Yes, but if the car is idling while completly stopped for 5 seconds or more it will idle at 650, otherwise if I roll down a hill at idle, it will be at about 1500 (until i come to a complete stop again for 5 or more seconds).

I noticed the ABSLT TPS reads 18% on my scanner while at idle, it doesnt change while idlling and stopped or while idling and moving. Is 18% within spec?

 

[98SVTC]

Yes, but if the car is idling while completly stopped for 5 seconds or more it will idle at 650, otherwise if I roll down a hill at idle, it will be at about 1500 (until i come to a complete stop again for 5 or more seconds).

Well, I've got to know if the car is in gear when you are "rolling" down that hill? How do you define rolling? And if the car isn't in gear, do you always roll down a hill in neutral or is that only while troubleshooting this "problem"? From my perspective, if your engine comes down to idle at 650 - 750 rpms after a few seconds, you don't really have a problem. If it always stayed at 1500, then I'd be more inclined to start looking at things.
Karl

 

[ubnpast]

Well, I've got to know if the car is in gear when you are "rolling" down that hill? How do you define rolling? And if the car isn't in gear, do you always roll down a hill in neutral or is that only while troubleshooting this "problem"? From my perspective, if your engine comes down to idle at 650 - 750 rpms after a few seconds, you don't really have a problem. If it always stayed at 1500, then I'd be more inclined to start looking at things.
Karl

I consider rolling to be moving at any speed, in neutral, anything but being stopped. It always stays at 1500 while moving in neutral, then idles down to 650 after being stopped for 5 or 6 seconds.

 

[98SVTC]

I consider rolling to be moving at any speed, in neutral, anything but being stopped. It always stays at 1500 while moving in neutral, then idles down to 650 after being stopped for 5 or 6 seconds.

Okay so do you ordinarily roll down hills in neutral? Engine breaking works wonders for car control and saves brake pads too. As I said, I don't think you have a problem. The smog control devices on the engine don't allow for the revs to fall to idle immediately in order to ensure that raw fuel gets burned before going out the exhaust.
Karl

 

[ubnpast]

Okay so do you ordinarily roll down hills in neutral? Engine breaking works wonders for car control and saves brake pads too. As I said, I don't think you have a problem. The smog control devices on the engine don't allow for the revs to fall to idle immediately in order to ensure that raw fuel gets burned before going out the exhaust.
Karl

Yes I know about the rpms slightly staying up, but not at 1500, its just not normal, the car was not doing this when I bought it, i was using the rolling down hills in neutral as an example, I usually do it if im getting off an exit...

 

[96SEMAN]

I'M CHASING THE SAME PROBLEM PRETTY MUCH RIGHT NOW-I THINK IT'S SOMETHING IN THE EVAP SYSTEM CAUSING THE PROBLEM-I FIXED ANY AND ALL VACUUM LEAKS AND PUT A NEW IAC VALVE ON,BETTER BUT STILL HAVE THE HIGH IDLE PROBLEM,WILL BE DOING MORE DIAG THIS WEEKEND-WILL LET YOU KNOW HOW IT GOES

 

[ubnpast]

I'M CHASING THE SAME PROBLEM PRETTY MUCH RIGHT NOW-I THINK IT'S SOMETHING IN THE EVAP SYSTEM CAUSING THE PROBLEM-I FIXED ANY AND ALL VACUUM LEAKS AND PUT A NEW IAC VALVE ON,BETTER BUT STILL HAVE THE HIGH IDLE PROBLEM,WILL BE DOING MORE DIAG THIS WEEKEND-WILL LET YOU KNOW HOW IT GOES

Sounds good, I think I only noticed this after removing and cleaning IAC, but not a 100% sure.

 

[ubnpast]

Ok I took a few short videos, the first shows my going from 0-50 then coasting in neutral, and coming to a stop (shows how the rpms stay up)


Now the second shows me stopping from about 30mph, and how it slowly idles down to 650.

 

[ubnpast]

Anyone?

 

[98SVTC]

Sounds good, I think I only noticed this after removing and cleaning IAC, but not a 100% sure.

If you're so dead set on this being a problem, then replace the IAC! Either that or downshift to at least second gear before coming to a stop and don't disingage the clutch until the engine speed is less than 1500. You shouldn't be coasting in neutral anyway in case you need to get out of someone's or something's way in a hurry.
Karl

 

[waldick]

sounds like either IACV or your intake has developed a leak somewhere. could be a leak around the IACV, like the gasket...

try running the motor and spraying carb cleaner around the various places it could leak and if the idle speed goes up, then you can narrow down the area of the leak...

i found an intake leak this way. when i pulled the UIM i found a gasket had failed. i replaced the gasket and it ran like a champ. the carb cleaner trick works very well.

hang in there and try it...a can of card cleaner is not expensive..

 

[ubnpast]

If you're so dead set on this being a problem, then replace the IAC! You shouldn't be coasting in neutral anyway in case you need to get out of someone's or something's way in a hurry.
Karl

Ill have to give replacing it a try, I actually chuckled when you said in a "hurry".

sounds like either IACV or your intake has developed a leak somewhere. could be a leak around the IACV, like the gasket...

try running the motor and spraying carb cleaner around the various places it could leak and if the idle speed goes up, then you can narrow down the area of the leak...

Ill have to give this a try tomorrow, I am assuming when the engine is cold?

 

[waldick]

doesn't matter if the engine is cold or not, since your problem is present regardless of the temp from what i recall ...

 

[ubnpast]

doesn't matter if the engine is cold or not, since your problem is present regardless of the temp from what i recall ...

Yes, but I dont want to potentially start a fire by spraying onto a hot engine..

 

[ubnpast]

Do you guys think that I should get a non oem for $41.79, or OEM for $69.79? I am sure if there is any problems with the non oem one that rock auto will take it back..