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Hi people,

I've got an interesting problem that I am hoping you all may shed some light on and possibly offer a diagnosis :) I have looked at the forum posts, and feel that my problem may differ from those already written about here.

Ok, I removed the car battery for several weeks (no power).... I then removed the pipe that connects the IAS to the pipe between the TB and the MAF as I was checking pipe diameters. I reconnected the IAS pipe to the intake, and ensured all connections didn;t leak.

With a new battery installed, my idle is now 1500 rpm !!! But, if I turn the Air Con on, it idles a little above 800, say 900 which I think was normal for A/C on... but if I turn it off, she jumps to 1500 !!!

I have disconnected the IAS hoping that it may reset, (this was while engine was running)... and she been driven about 2 hours now so I hope the ECU has learnt anything it needed to from being disconnected.

I've checked the manifold for leaks, and the TB cable is not holding on.... so I'm at a bit of a loss here..... any advice or checks appreciated :)

Tnanks guys and girls :)
 

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when you ias do you mean intake air temp sensor? I assume so.... I would hook that back up as it was and check the hoses going to the idle speed actuator. Carefully check them for cracks/leaks. You could also pull the idle speed actuator off and clean it with some brake cleaner through each air side of it and clean the plug in connector with some electrical cleaner and see how it reacts. They build up with gunk rather quickly it seems....
 

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check your vacuum line..the diagram should appear underneath the hood..

if a rubber vacuum line is ruptured or cracked..it'll let of pressure and raise the idle speed opf the engine..
i found this out when installing my auto meter vacuum gauge..

it will also idle high if there's a leak in the intake pipes..so seal em well.
 

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Discussion Starter #4
Hi People,

Thanks for the info so far... sorry about my bout of dislexia... I meant the ISA, as in Idle Speed Actuator.

Omg: Thanks mate... I have checked the pressure of the hoses on both side of the ISA and they both hold pressure (I blocked one end then blew into them with no leaks). I have used Electrical Cleaner on the connections and have cleaned out the ISA with TB cleaner. But unfortunately, the problem still exists.

Tak: Um, yeah, sounds like I need to toss around a soapy water solution to find a leak in one of the lines !! Um, mine has the plastic intake too... so yes indeed their may be a cracked intake runner !!

It's interesting though.... that it will sit on 1500rpm... then I turn on the Air Con and the idle drops to perfect... turn off the Air Con and it jumps to 1500rpm !!

I had considered if the TB is fully closing !! But wondered why when the Air Con is on.. that the idle is ok.... I'd be happy to drive with the Air Con on, but the poor little engine is underpowered !! Well, until the turbo is installed (soon, still waiting for it to arrive from the USA)

I'll give some more lines some scrutiny, and see what I find..... I have to go away for a couple of days, so will get to it on Sunday.

Many thanks again... and feel free to make further comments as seen fit.

Safe driving :)
 

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It sounds like a leak to me. I just had my entire charged side of my intake disassembled this past weekend to install the fmic (which didnt even get done lol) and have a leak with the same exact problem your describing. One the clamps i put on went at an angle and off the coupling, no big deal i just dont feel like fixing it when im taking it apart again this weekend lol Neways it idles about 1500 which i turned down too like 1150 and it went back up to like 1300. When I turn the a/c on its right where it should be....
 

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any other symptoms? is that car maf or map? if maf and it was a leak, wouldn't the car idle up and down? or almost stall out when starting to move?
 

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Mine would stay pretty steady until the cel came on saying rpm to high/low for idle then it would start some crazy stuff lol
 

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Discussion Starter #8
Yeah, the revs stay pretty steady... but with the A/C on, it's fine !!... I think I'll put the new manifold on... and hopefully that may fix the issue.... or maybe I'm up for a new Idle Speed Actuator !!... although I'm not convinced that that is the issue.. due to the revs being correct with the A/C on !!... Oh well, thanks people... I'll plod along with it, and see what happens.

Safe driving !!
 
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