calsupra Posted October 6, 2014 Share Posted October 6, 2014 So my mot was up on friday and a few days before i occurred a problem with my na idling high after you rev it. On first start up when hot the revs go up to 1200 and drop to 1000 then once you blip the throttle over 2000 the revs come down but stick at 1500. If i turn the engine off and back on the revs return to normal, but soon as i touch the throttle it idles high. I put it through the mot anyway but it did not pass because of this. So far i have taken the throttle body and idle control valve off and gave them a good clean in a attempt to fix the problem but it did not work. Video: https://www.youtube.com/watch?v=fCF0ZYOHJ6g&feature=youtu.be Quote Link to comment Share on other sites More sharing options...
Slam Posted October 6, 2014 Share Posted October 6, 2014 It's a manual yer Quote Link to comment Share on other sites More sharing options...
calsupra Posted October 6, 2014 Author Share Posted October 6, 2014 It's a manual yer yeah Quote Link to comment Share on other sites More sharing options...
mellonman Posted October 7, 2014 Share Posted October 7, 2014 is your air con on ? Quote Link to comment Share on other sites More sharing options...
calsupra Posted October 7, 2014 Author Share Posted October 7, 2014 is your air con on ? no my air con is broke, some times it lights up but i turn it straight off Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 7, 2014 Share Posted October 7, 2014 Pull the crankcase ventilation valve out of the cam cover and block it with your finger. Does the idle drop and stabilise? If so consider the option to vent the engine to atmosphere and delete the valve. Quote Link to comment Share on other sites More sharing options...
calsupra Posted October 7, 2014 Author Share Posted October 7, 2014 Pull the crankcase ventilation valve out of the cam cover and block it with your finger. Does the idle drop and stabilise? If so consider the option to vent the engine to atmosphere and delete the valve. This does not seem to make a difference. The problem started when i dropped down a gear on the motorway trying to keep up with a friend in his GTR. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 7, 2014 Share Posted October 7, 2014 High idle can only be excess air for the fuel and timing at that point. You need to scope the signals to the ICV, and check it's receiving the right drive waveforms, and also cycle it and see if it respinds quickly and correctly. Pour water over the intake system with engine running to see if there are external air leaks. Check TB assembly for wear. N/A's are a pain for high idle. You also, of course, need to see the throttle pot is set *EXACTLY* as per the manual. DO NOT twiddle butterfly stop screws!!!!!! It's often much easier and cheaper to take the car to a good garage with the right gear, and let them sort it. You have to put a price on your own time. Quote Link to comment Share on other sites More sharing options...
calsupra Posted October 7, 2014 Author Share Posted October 7, 2014 High idle can only be excess air for the fuel and timing at that point. You need to scope the signals to the ICV, and check it's receiving the right drive waveforms, and also cycle it and see if it respinds quickly and correctly. Pour water over the intake system with engine running to see if there are external air leaks. Check TB assembly for wear. N/A's are a pain for high idle. You also, of course, need to see the throttle pot is set *EXACTLY* as per the manual. DO NOT twiddle butterfly stop screws!!!!!! It's often much easier and cheaper to take the car to a good garage with the right gear, and let them sort it. You have to put a price on your own time. I was just checking for leaks while it was idling high and decided to tap the Y shape intake with the back of a screwdriver and it suddenly dropped from 1200 to 900 rpm what could this mean? Quote Link to comment Share on other sites More sharing options...
Nodalmighty Posted October 7, 2014 Share Posted October 7, 2014 I was just checking for leaks while it was idling high and decided to tap the Y shape intake with the back of a screwdriver and it suddenly dropped from 1200 to 900 rpm what could this mean? Sticking idle valve, possibly the TPS is just borderline on the idle circuit contacts (Adjust TPS). Quote Link to comment Share on other sites More sharing options...
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