high idle during day normal at night early morning

[niddydsm]

So i have a 95 tsi nd this problem is abnoxious... when i first start it up she idles fine. When it starts to warm up outside the idle will creep to 2.5-3k and will not drop. If i was to drive at night it idles perfect. Wondering if this could be caused by a bad MAF, or should i look else where?

 

[shane90gsx]

FIAV.. Or fast idle air valve in the T/B or T/B position sensor. Both sensors on the T/B itself. The other cause could be a vac leak. This will be the easiest test for u to try. Any vac leak messes up the idle. One thing I did was go to Throttlebodys.com and have him replace the shaft seals, the flap seat, and test the two sensors

 

[niddydsm]

I check tps, im gonna check the fiav. Also recently when its starts acting up i can quickly hit tge throttle and it will drop to 1500, could the issue now be leaning towards the IAC ?

 

[ricktb]

adjust the throttle cable with the 2 nuts on top near the throttle body. Best is to wait for the idle to reach its highest point, and then loosen then nuts to give some slack on the cable so the throttle plate can close fully, and then tighten back down. I had the same exact problem and through post on dsmtuners I finally found the culprit.

The reason, my theory is.. when the engine compartment is hot, the throttle cable jacket expands and gets longer slightly, thus more slack on cable is needed to allow the throttle plate to close fully. usually comes with engine mods that increase under hood temps (manifold etc..) ambient air temperature can also affect under hood temps, eg night vs day

 

[niddydsm]

THANK YOU BUDDIIEEE!!!! ^^^^ +12. So I adjusted the cable and it worked for about 15m, so I had this wierd notion to hit the cruise control box. Well as soon as i hit it the idle jumped about 1k from 2k to 3k. I removed the cruise control cable (the cable that doesnt goto either the throttle or pedal) and needless to say I LOVE MY IDLE. thank you again for your help