Datalog at idle...

[GT40MkI]

Latley the car has been acting strange.

90 Tsi AWD, 2.4 680cc, MAF-T with 3" maf, PTE 56 Trim...stock cams...


Problem is that after about 2-3 minutes of running it wants to run extremely rich at idle or part throttle, or even WOT.

I realize the MAF-T is a "band-aid" for a real EMS, but decided to log it regardless...I let the car idle, with an occasional rev to make sure it was logging, for about 4.5 minutes.

Low Fuel Trim stays at 81% for the duration of the log.
Mid Fuel Trim stays at 84% for the duration of the log.
High Fuel Trim stays at 81% until there is a spike at 3:22. It pegs 199% for less than a second and then returns to 81% for the duration.

Temp was 230-240 for the duration...I need another fan but oh well...it never gets that hot if its moving...


O2 voltage dances around .66, sometimes wavering from .40 up to .80..but comes back to .60ish for the first minute, then does the same behvaior around .80 for the second minute....then finally up to .90 for the last minute and a half.

Oxygen Feedback trim is at 0 for the majority of the time, with the exception of every 60 seconds when it jumps up to 100% for about 6 seconds.

Any ideas/anything else to look for?

 

[kpt4321]

Something is not right. Is the car FULLY warmed up for this?

I want to make sure the O2 sensor is cycling correctly. That O2 trim is not right either.

 

[talon1979]

It sounds to me like maybe the o2 sensor is taking a dump.

 

[GT40MkI]

Originally posted by kpt4321
Something is not right. Is the car FULLY warmed up for this?

I want to make sure the O2 sensor is cycling correctly. That O2 trim is not right either.

Temp was 230-240 for the duration...I need another fan but oh well...it never gets that hot if its moving...

I'll look into the o2 sensor-makes sense....

What about the fuel trims, way off? Shouldn't there be a little more activity?
Thanks to both of you for the replies...

Anyone else?