• Welcome to the Contour Enthusiasts Group, the best resource for the Ford Contour and Mercury Mystique.

    You can register to join the community.

What's your idle speed?

previously found that even if the th stop screw is adjusted to keep the tb plate slightly open the PCm will compensate and lower the idle after its to high because of the open tb plate.
 
BrApple said:
previously found that even if the th stop screw is adjusted to keep the tb plate slightly open the PCm will compensate and lower the idle after its to high because of the open tb plate.
Click to expand...

It really should be able to adjust but I know people have had idle issues when air gets around the blade. The IAC is just a little throttle body controlled by the ECU. Do cars with electronic throttle have an IAC? I wouldn't think they would need it if the ecu can control the throttle position.
 
Blackcoog said:
It really should be able to adjust but I know people have had idle issues when air gets around the blade. The IAC is just a little throttle body controlled by the ECU. Do cars with electronic throttle have an IAC? I wouldn't think they would need it if the ecu can control the throttle position.
Click to expand...

cars with an electronic throttle dont have an IAC. they do just what your thinking and the PCM just opens and closes the throttle as needed to maintain idle.
 
Blackcoog said:
I believe the throttle body should be completely closed at idle. If the set screw was turned to crack the throttle blade open then it should be turned back so the throttle blade completely shuts. The IAC entire purpose is to pull in air to keep it at idle.

Also, if the throttle body was ever polish or modified internally around the throttle blade it could affect the idle. You should never polish/grind/sand the area around the throttle blade unless you want the car to idle really bad.
Click to expand...

I suppose that makes sense... however I've seen a number of cars before that have had IAC and there TB's were cracked or had a through hole near the center of the butterfly, which doesn't really jive with what your saying.
 
They do have a small hole in the plate but they are closed at idle. After some searching online it sounds like the hole needs to be there or the plate has to be cracked open slightly like you mentioned. Some say the hole is there to prevent the butterfly valve from siezing closed under vaccum which make sense.
 
i have a full 3L untuned & i am idling @ around 1200-1000. itll go to 1200 for a few sec then drop to 1000. the car doesnt sound or feel like it is revving high. it feels just like my stock 2.5 did. but every once in awhile it will drop below 1000 & it seems rough like it almost wants to die. ive checked a few times for vac leaks but wasnt able to find anything. used the propane method & sprayed carb/intake cleaner & wasnt able to source a leak.
 
double_u_4 said:
i have a full 3L untuned & i am idling @ around 1200-1000. itll go to 1200 for a few sec then drop to 1000. the car doesnt sound or feel like it is revving high. it feels just like my stock 2.5 did. but every once in awhile it will drop below 1000 & it seems rough like it almost wants to die. ive checked a few times for vac leaks but wasnt able to find anything. used the propane method & sprayed carb/intake cleaner & wasnt able to source a leak.
Click to expand...

same thing when i have my full 3L untuned. sometime sit would run. sometime sit would stall every single time during idle. the pcm does •••• when your running mad rich. not sure if your are tho since i dont know what ur running. but i wouldnt worry about it until u get a tune. it fixed everything
 
You must log in or register to reply here.
Back
Top