Not sure where to start with idle problem

[1_2befast]

Well, I think this is actually my first post here even though I have frequented the site for a couple of months.

I just bought my 92 tsi awd about a month ago, and it has the following mods that I know of: 660's, fmic, 20g turbo, 2g maf, tial bov and wastegate, hks 272 int/exh cams, safc.

Anyway when I got the car it idled a little fast, 1200-1300 rpm. At this time I would get no reading from the a/f gauge and when throttle was applied the leds on the autometer guage always came up from the lean side. Skip ahead, the idle progressivly got worse (2800-3000rpm) and a friend of mine who knows turbo cars pretty well (he has a 400hp 4cyl turbo mustang that he built) started to tweek the low throttle fuel trim to try to achieve stoich. We did get stoich, but the idle was still fast (2200rpm or so). The weather has gotten a lot colder, so those settings are now too lean, but I don't think that is the problem. On the SAFC, I am reading up to 1% throttle at idle and it is reading .605-.615V at this point when I go to the sensor check. Also it does surge very occasionally, and there are no boost leaks other than the controlled one between the MBC and wastegate.

I don't know if the tps just needs adjusting or where to start. It doesn't sound like the ISC motor from what I have read, but what do I know. I hope to get a chance to work on it next week while I have off from school. Thanks for any direction you can give.

Russ

 

[gurmanator]

start from scratch with everything.it sounds like you have to many things going on at once.set everything to zero.check for vacuum leaks.

 

[1_2befast]

I know there is a lot of stuff going on, but I don't quite get what you are saying by turn every thing back to zero.

 

[tranman91]

Have you tried adjusting the BISS?...(base idle set screw)...It may help your problem.

Read this...http://www.plymouthlaser.com/biss.htm

 

[Gary 420A RS]

skip everything else said and go straight with dsmlink. it would take care of your idle problems as well as others you can set your car to run perfectly with just that and a laptop.

 

[tranman91]

skip everything else said and go straight with dsmlink. it would take care of your idle problems as well as others you can set your car to run perfectly with just that and a laptop.

Going straight to the pocket book for DsmLink is not going to magically make your car run perfect...Especially if the problem is due to mechanical failure.

Due some more research and find out how other members solved their problems...Your fix could be as easy as 10 minutes and some pocket change.

 

[1_2befast]

Well a big part of it was the BISS. I think it must have loosened over time and the other day I started to hear a vacuum leak and geuss what was missing. So anyway I did the junk yard crawl to try to find one with no luck, guess its time to go to the mitsu dealer. Anyway, I will let you guys know how things go once I get a BISS.