idle surge issues

[redline7]

well when I start my car in the morning it starts ok and idles alittle rough but acceptable around 800-900 rpm. Now I can drive the car anywhere but as soon as I park the car and then restart it I would usually get a idle surge to about 1400-1600 rpm. I switched tb's with a extra one and backed my throttle cable all the way loose. when ever the idle is surging I can usually pull the tb cable close and the idle returns to normal until I let go of the cable. I have been messing with my cables adjustment but no luck there. I am leaing towards a slight vacuum leak by the tb. probably the old gaskets I re-used.

 

[TurboHawkTSI]

Most of the time it will be a leak at the TB. If you haven't replaced the seals in the TB I would recommend that but I'm curious, what is the range in rpms that the surge takes place, minimum to maximum? You may need to adjust the BISS but if you haven't touch it or replaced anything I would recommend doing a pressure test on the system. When pressure is applied, not over 20 PSI, open and close the throttle body and see if there is any leakage around the throttle arm itself. If so you need to replace the seals which is a pretty easy job.

 

[redline7]

Most of the time it will be a leak at the TB. If you haven't replaced the seals in the TB I would recommend that but I'm curious, what is the range in rpms that the surge takes place, minimum to maximum? You may need to adjust the BISS but if you haven't touch it or replaced anything I would recommend doing a pressure test on the system. When pressure is applied, not over 20 PSI, open and close the throttle body and see if there is any leakage around the throttle arm itself. If so you need to replace the seals which is a pretty easy job.

The surge can range from 1100 to 1800 really. when the car idles normal it sits at about 700-800. when I get a chance to do some testing I will update the thread.

 

[Silver 95 GST]

Try slacking up your throttle cables. It sounds like the cable is too tight and is partially

opening your butterfly valve in your throttle body. That's why when you turn the throttle

plate it closes more. I just adjusted mine and I had the same problem. I was suprised at

how much slack the cable needed at closed. But at hot your cable housing expands

making your cable effectively shorter.



If that doesn't work try the traditional methods of

idle surge troubleshooting, i.e. vfaq.com