hey guys. im having a serious issue.

im getting rough starts and stalling out on accelerations with my jeep. and the other day it threw the code "IAC high voltage"

this is what i have in it and have done sofar.

whats in it:
bored 63mm tb
k&n CAI
all under a year old sensors in the TB (IAC,MAP,TPS)

so i warrantied my iac and got a new one and that hasn't worked, im cleaning it now as we speak but its pretty clean already so yeah....

and i haven't taken a look at my tps yet but that's almost new too.
what do i do from here?

thanks

 

I read a few manuals recently about Idle motor check.
1. They have 2 coils (4 pins) with the same resistance.
2. Easiest check:
*When you switch from park to drive RPM should be the same or slightly higher. If idle motor is dead, RPM will drop or engine stall.
* same about turning AC on
3. there were somewhere instructions to remove Idle motor, but keep connector on. Rod should move, when you turn ignition on and off. Not sure which manual that was in. There can be a problem to install it, if rod is out too far.

 

thanks but it wont start so i dont know how well this will work, and im not sure if its the motor itself because i now have a brand new one in it

 

the "IAC high voltage" means the sensor is receiving too much voltage and is most likely shorted-to-voltage. There is probably nothing wrong with the sensor at all. It is now most likely a wiring problem. start with the connector right there and make sure to visually check the wiring harness all the way back. pigtails and spots where the wire gets hot or twisted/rubbed are main culprits. clean the connections and wiggle the wires at the pigtails. It is probable that the wires could be shorting to each other or to other wires in the harness, if you said youve tried multiple sensors.

 

thanks, i fixed that issue and now i have another iac issue. that previous one was a fuel pump gone bad

heres my problem now.....

my iac reads high voltage when it goes bad. however the issue now is it only goes bad in the morning.

so at absolute cold start my engine will stall, then misfire, then the stupid light will come on (check engine), then idle at 2k in park and 1k in drive. its done this the past 2 days and ive replaced my plug on it recently and im prob going to warranty the iac again in the morning if it does it again

 

I have a similar problem and would like to have a resolution to this. I'd love any comments or opinions on my situation .

Here's what happened to mine:

It would occasionally stall in park when i started it from cold, and had a little bit of a rough idle.

So I took out the IAC and cleaned it(unplugged and removed 2 T-20 screws) with seafoam throttle body & intake cleaner.

I think i may have damaged it because after i reinstalled the IAC valve my jeep doesnt want to start unless i give it a shot of gas while turning it over. Then it starts but i have to keep my foot on the gas for 2-4 minutes before it will stay running on its own.

The idles will smooth out after about 5-7 minutes but if i turn the engine off and try to fire it back up, the same thing happens all over again.

Thanks for replys.. ps- i am posting on this thread because im new to the forum and have not yet figured out how to start my own thread.

 

My idle was basically stuck at 2500rpm. Checked all around for vacuum leak, cleaned the throttle body with no change. Finally changed the Idle Air Control motor and engine idle is back to normal.

 

Does anybody think I could have fried something else besides the IAC valve, causing it not to fire up properly??

 

Remove the IAC, leaving it plugged in and have someone try to start the engine. You should see the IAC plunger move. If it doesn't move, it's broken.

Did you happen to bump or disconnect the TPS while working on the IAC?

 

ok i'll try these few things and get back with my result, thanks radi

 

Ok, first start this morning and it fires up right away with a high idle. Now I have to shift to N when stopping at red lights because it idles high and out of control..... IAC is done??

Thanks for replys...

 

That's where I'd start.

 

Ok... now today the idles seem 'better' but its making a weird whistling/ringing noise when i decelerate, and sometimes also when i accelerate... I wish i had never cleaned this iac because i have more problems now then i had before!

 

Are you sure you have all your vacuum lines hooked back up, you may have knocked one off or cracked a boot.

 

Ive been having a IVAC issues. Mine is just cold morning start.

She turns over EZ but wont stay running unless I give it gas. After about a 45 seconds of gas at about 2500 rpm or so she'll idle fine.

My IVAC is fairly new maybe 2 months old.

just thought Ill throw my 2 cents in