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A/C idle issues. Need my A/C!!!

6K views 44 replies 9 participants last post by  Aman12011 
#1 ·
Hello, newbie here. I’ve been on the forums searching for this issue but can’t find it. If there is something out there, my feelings won’t be hurt, please send link. Well here goes....when the air conditioning is off, the car purrs like a kitten, absolutely no issues! Idle is at 1000-1100. However once the a/c is running, when I come to a stop or have the car in neutral she has a very erratic idle and then shuts off. I’ve read not having heat shield for the intake could send hot air, while the a/c is running, in that area and throw the MAF for loops. So I bought a MAP Rev 2 heat shield to aid in this issue. Installed it, took it out for a drive and the EXACT same thing is happening again! Again if there is a link please send.

Thanks
 
#2 ·
Would re-learning idle help or not. Anyone?
 
#5 ·
Thanks. I’ll get on this.
 
#6 ·
Update...Checked the lines and found only these two (or one) not connected. Did a compression check, nothing less than 162 on all 4. Haven’t done the throttle body clean yet. Being methodical is ok with me not in a big rush.
 

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#7 ·
Oh sorry I did clean the MAF. :imstupid:
 
#8 ·
Same outcome.:slaphead:
 
#10 ·
Ok.
 
#11 ·
hey i posted this here too (https://www.evoxforums.com/forums/showthread.php?t=401192)



I had the same issue a while back. turned out to be a dirty throttle body plate, in my case at least.

Apparently our cars adjust the throttle plate a little bit at idle, and when it gets dirty, the plate can kind of get stuck. It prevent the plate from making really small adjustments when it needs to such as at idle.

As soon as the shop i go to told me this, i wiped the throttle body with a rag, put it back together - and it solved the issue.

best of luck
 
#13 ·
Update: Cleaned the throttle body with CRC throttle body cleaner...fixed. Thank you for going through what you did it saved me so much time and headaches. Idling around 900-1000 with a/c on or off. Sorry to you fellas up north bout all the A/C talk. Keep safe up there.
 
#12 ·
Thanks for the info. Will do this as well. :thumbup:
 
#16 ·
Thanks!
 
#18 ·
Welp only after 2 days...I lost boost and threw a p0171 code. I was going to work, had boost and halfway there bam no boost. I was down to almost an empty tank. Stop filled up and no boost. Came home re-checked the hose to the throttle body and it’s on tight. Checked all other hoses and connections...all tight. Cleaned MAF again also. Any thoughts?
 
#20 ·
If you havent thrown this code before on ur current set up, and you havent changed anything other than diagnosing that AC idle issue stuff - i would put my money on a vacuum/boost leak.
read somewhere on here about a loose fuel pressure reg vacuum hose causing this as well.
 
#19 ·
Sorry forgot to include....no white/black/blue smoke whatsoever. No oil leak. Idle is same as before.
 
#22 ·
FPR reads 20 psi. Looks like fuel pump took a dump. Getting new one.
 
#23 ·
Went to switch fuel pump out and found a deep cut in a hose. Put new hose on...problem solved.
 
#35 ·
Hello again! 3 months & 2000 miles ago the exact same issue raised its head again. Is this normal for the throttle body to cleaned again so soon? It’s not to difficult to get to and clean but I can see this is going to get annoying. Is there something I’m doing/not doing with the TB? Is there a TB coating of some sort? Would buying a new TB solve this? Any recommendations?
 
#36 ·
I only had to clean it once around 45k or 50k miles, and the issue didn't come back.
@ around 65k miles I removed my intercooler and piping before doing a turbo/engine build,
and i noticed ALOT of oil/sludge in the bottom of the intercooler and the lower piping as well as a little build up on the TB plate again.
This may have been a sign that my turbo was on its way out, but i wasnt experiencing any idle issues.
I ended up getting a new intercooler/turbo and a fresh built engine so I never found out for certain.
 
#37 ·
Opened it up and saw no signs of any oil, cleaned it and it’s back to normal. I’m getting a mishi X line rad this week so I’ll check the IC for oil when I pull all that apart. Thanks for the response.
 
#38 ·
Did the TB plate have oil/dirt on it again?

If it wasn't dirty then your problem is probably something else. I cant believe it would get dirty enough to cause issues again that quickly, after all it took me almost 45k miles to have that issue come up. But i'm no expert.
 
#39 ·
There was some black dirt on the rag when I wiped it. I continued until no more dirt was left on the rag.
 
#42 ·
It was the idling with the air con on. Cleaned the TB and back to idling normal.
 
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