Unplugged IAC and no change in Idle

[Legendary]

Does that mean the IAC is bad?

I a very bad case of hanging idle. I cleaned the IAC and I was going to set the idle. According to the list you should unplug the IAC and the idle should drop right? Well mines idles like nothing happened. Is it time to buy a new IAC? The 1500 RPMs at the red light is driving my nuts!

 

[cardudeusa]

My car will stall out when I unplug the IAC, maby you have the idle set too high? TPS could be out of wack also.

 

[Legendary]

I would have to buy a volt meter to check that right?

 

[cardudeusa]

I would have to buy a volt meter to check that right?

Yeah, I've never had to mess with mine, so I cant tell ya HOW to set it, but a cheep $15 digital multimeter and a haynes manual should be enough to get it done.

 

[Mustang5L5]

It could mean your idle set screw is set way too high and the IAC is closed up trying to lower it.

WHat i do is set my idle with the IAC unplugged as low as possible. I try to get it right above the point where it starts running rough and any load would kill it.

Then i reset the computer and plug in the IAC. It will idle fine and there is room to idle up and down slightly. It will still idle up to 1500 RPM.

 

[347 Special]

when you say you cleaned it, what did you clean it with? Did you take it apart? is the plunger bad/sticking? Try to re-set your idle before you by a new one far as i know they are costly. Diss. conn. your battery for 15-20 and unplug your IAB and reconnect your battery,start your car and set your idle around 700-850 with the idle screw(how big is your cam? if your cam is stock that should be a good setting) then turn car off and reconn. the IAB and run the car for a couple mins. turn off for a couple mins. and then start car and run with ALL accessories on for a couple mins. and turn off. You should notice a difference and it should idle nice. As far as the TPS get a meter and put the black to a ground and the red to the GREEN wire on the TPS. Turn the ign. on(dont start) and you want a reading from .95-.98/.99
if your not in that area loosen the screws slitely and wiggle the TPS till you get in that range and tighten the screws up and recheck to make sure the TPS didnt move. GOOD LUCK , let us know the results

 

[HISSIN50]

for your problem, have you made sure you dont have any vac leaks? they cause a hangin idle.
good luck.

 

[FOXBDY89]

You might want to try this website, http://www.muscularmustangs.com/maintain.html
I am having the same problem but mine is not constant. It only happens once in a while but my idle hangs at 2200rpms. I was just surfing the net and found this site. I am going to try this when I get home today. It is basically what everone else already said but there are a few more tips in there to help you out.

 

[Legendary]

Thanks guys. I didn't mess with the tps but I did reset the idle and computer. I'll drive it around a little when I get home and see how that works out.

Good link foxbdy89. I added to my car page.

 

[TheUser]

if you reset the idle, you HAVE to reset the TPS.

 

[Legendary]

if you reset the idle, you HAVE to reset the TPS.

Damn.