Why is my idle so high?

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MADVR4

Well-Known Member
Joined
Aug 3, 2005
Messages
557
Location
Melbourne VIC
Hey guys im after some help.

Ive changed the Throttle body on my galant to another standard Jspec vr4 one... mind you this is going into an Aussie Manifold (Non Cyclone). Im running Microtech ECU that has been dyno tuned. Ive screwed the the idle screw all the way in and reset the TPS sensor on the Microtech hand controller. But its still sitting at 1600rpm standard idle. Ive played with the throttle cable and there is not to much tension on it etc.

Ive also checked that the TB is grounded and it seems to be.

The little single plug on top of the TB that runs to a sensor does nothing if i pull it off or on???

Any help would be awesome.

Cheers
Grant
 
i had similar thing, i thought it was tb as the throttle was shut, the little screw thing was wound in an it still idled high.
so i pulled off the intake elbow and put a bit of sticky tape over the holes that are the feeds for the idle control and the port for the cold idle up.
then it wouldnt idle.
so then removed the part that covered the idle control, leaving the cold idle up covered. the car idled fine. this told me the cold idle up had a issue. so i changed bottom section of tb and then it was fixed.
try similar process of elimination to find the broken part.
 
I think the jspec and aus spec have different throttle body flanges.

You might have a big leak on the lower half of the t/b.
 
you could have your throttle cable on too tight, this will cause it to idle high. there should be some slack on the cable when the throttle is closed
 
Make sure that your idle switch is not keeping it open. It is possible that it was adjusted that way on the car that it came from.
 
Hi Guys, every now and then my engine hunts up and down on idle, then when i remove the loom plug that connects to the sensor on the thottle body, it stops, does any know the cause of this?.
 
Adjust your tps? Look up www.vfaq.com under intake For how to do this. I did this and car idles fine. I still have to remove my tb as I suspect a minor air leak underneath.
 
Check TPS volts, check for vacuum leaks, if you believe its the FIAV playing up (Bottom half of the body) you could delete the FIAV and leave the ISC intact, check the ISC is all good by all coils in the 30-80 ohms range. Good Luck
 

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