bpe121212
15+ Year Contributor
- 59
- 2
- Apr 24, 2006
-
Lynchburg,
Virginia
Hey guy's,
It is my understanding that 2G dsm's idle rich at cold start up until reaching a target operating temp of ~ 180 F (?) and then they use the O2 sensors to maitain a ~14.7/1 A/F. I might have this wrong though!
Here is some basic background info on my 1995 TSI AWD: Garrett BB 50 Trim, 750 injectors, 255 pump, 6an SS fuel line, Aeromotive Fuel filter and AFPR, ECU + ems, ECU chipped for 750 injectors, PLX 300 A/F, FMIC, Greddy RS BOW (recirculated), Tial external waste gate, HKS 264 intake and exhaust cams. I have already done a boost leak test - no leaks. New Biss screw and Idle control motor (calibrated). I removed evaporative emmisions control system, and istalled EGRPlate on intake.
See profile for more info if needed.
I am having the folowing symptoms and just can't seem to figure out what is going on!
At cold startup, car idles for ~ 10 seconds at ~1500 -2000 rpm. The idle then proceedes to drop, stumble and stall. once O2 sensor heaters have warmed sensors you can see the A/F go as high as 19/1 as it stumbles. If I restart and rev the car to 2000 and higher until it warms up or go drove the car to worm it up, it will idle for a short period at ~14.7/1 and then begin to go lean again and stumble (A/F at ~17-19/1). Once the car is fully warmed up the lean idle is there sometimes and not there at other times. The car will also often stumble when it is reved and then alowed to come back down to an idle (similar symptom seen when a BOV is vented to atmosphere when using the stock MAFS instead of a MAP sensor.)
The car runs great at cruise (~14.7/1) and at 20psi of boost WOT(~11/1) - no knock. The cause of this lean idle issue has become very frustrating to diagnos and fix! any help would be very much appreciated!
Pres
It is my understanding that 2G dsm's idle rich at cold start up until reaching a target operating temp of ~ 180 F (?) and then they use the O2 sensors to maitain a ~14.7/1 A/F. I might have this wrong though!
Here is some basic background info on my 1995 TSI AWD: Garrett BB 50 Trim, 750 injectors, 255 pump, 6an SS fuel line, Aeromotive Fuel filter and AFPR, ECU + ems, ECU chipped for 750 injectors, PLX 300 A/F, FMIC, Greddy RS BOW (recirculated), Tial external waste gate, HKS 264 intake and exhaust cams. I have already done a boost leak test - no leaks. New Biss screw and Idle control motor (calibrated). I removed evaporative emmisions control system, and istalled EGRPlate on intake.
See profile for more info if needed.
I am having the folowing symptoms and just can't seem to figure out what is going on!
At cold startup, car idles for ~ 10 seconds at ~1500 -2000 rpm. The idle then proceedes to drop, stumble and stall. once O2 sensor heaters have warmed sensors you can see the A/F go as high as 19/1 as it stumbles. If I restart and rev the car to 2000 and higher until it warms up or go drove the car to worm it up, it will idle for a short period at ~14.7/1 and then begin to go lean again and stumble (A/F at ~17-19/1). Once the car is fully warmed up the lean idle is there sometimes and not there at other times. The car will also often stumble when it is reved and then alowed to come back down to an idle (similar symptom seen when a BOV is vented to atmosphere when using the stock MAFS instead of a MAP sensor.)
The car runs great at cruise (~14.7/1) and at 20psi of boost WOT(~11/1) - no knock. The cause of this lean idle issue has become very frustrating to diagnos and fix! any help would be very much appreciated!
Pres
