need help idle problem

[talondude4]

My buddy just bought a 95 talon tsi fwd. The car when it first starts idles up high like any normal start and lowers, then after driving the idles at 1700 rpm. We let the car sit for a bit then the idles slowly drops down to about 1200 rpm after sitting for like 15 min. i was thinking temp sensor maybe cause but im not sure. any suggestions? car is completely stock and is not venting to atmosphere.

 

[misphit]

Sounds like the throttle cable is too tight. Back if off while the car is running at normal operating temp to set it at the correct tension.

 

[Hubbell91Tsi]

Idk, but it sounds normal to me.

 

[KevinRR]

Try adjusting the cable like misphit said and if that don't help clean the TB.

 

[talondude4]

cable is loose at running temp, the cleaning the tb i will look into, any tips on that? i was thinking it may be the throttle position sesnsor, i unplugged it and nothing happen with the car.

 

[nyTalonTsi]

Is there any idle surge? Might be a leaky biss screw because it needs replacement along with the o-ring.

 

[rEclipserGST]

Is there any idle surge? Might be a leaky biss screw because it needs replacement along with the o-ring.

+1 or try adjusting the BISS screw, with the car on take a screwdriver and push the screw down, that should lower the idle a bit. Sometimes these screws get a little loss and start to back themselves out due to all the vibration of the engine.

 

[talondude4]

what is the biss screw and were is it located?

 

[deerhunter0881]

it is in the front of your throttle body and can raise or lower your RPM

 

[talondude4]

tps is working, we figured that much out. we cleaned the TB, and we still have hi idle. The biss screw, well dont even see a screw head down in the hole??? no leaks, checked over all vac lines no splits nothing, clamps all tight. when we first started the car before it came to full temp, we moved the tps position and brought the idle to normal, and we took it for a drive after and the idle went up higher then before. i am at completely lost here.


btw this car sat for 2yrs before he bought it.

 

[ChowMein]

its my car the guy i bought it from had it sitting for 2 years i don't think he ever started it until when i went to go pick it up it had very crappy gas in it but ive run 2 tanks through since then we've tried everything im ordering a new blow off valve on Tuesday that's the last think we can think of it can be the engine runs basically mint but it just has that high idle anywhere from 1500 to 2100 rpm's
so anything that we haven't tried would be a big help its killing my gas mileage right now burns a lot of gas just idling

 

[misphit]

The biss screw, well dont even see a screw head down in the hole???

Huge problem right there. Find a BISS promptly from somewhere and thread it in there. I'll bet that solves your idle issue.

 

[talondude4]

thing is we cant tell if its a screw with crap caked on top of it or if its rtv or something, the guy was a damn rtv whore. we can take a pic tomm so you guys can tell us what you think.

 

[ChowMein]

heres 2 pictures of the biss screw or the lack of there kinda blurry i tried to get good ones but thats the best i could do