Does the MAF control fuel trim for each bank?

[finesse]

Vagcom says fuel trim at bank 1 is rich, would a MAF change sort this or is this a possible injector problem?

2001 AMK

P.S
If the oxygen sensor was faulty, would it come up in a scan?
Where the feck is the Fuel Pressure Regulator?

17545/P1137/004407 - Fuel Trim: Bank 1 (Add): System too Rich

Possible Symptoms

• Malfunction Indicator Light (MIL) active

Possible Causes

• Mass Air Flow (MAF) Sensor faulty
• Fuel Pressure Regulator faulty
• Fuel Injector(s) faulty
• Oxygen Sensor Control faulty
  • Oxygen Sensor(s) faulty
• Evaporative Emission (EVAP) System faulty

Possible Solutions

• Check Mass Air Flow (MAF) Sensor
• Check Fuel Pressure Regulator
• Check Fuel Injector(s)
• Check Oxygen Sensor Control
  • Check Oxygen Sensor(s)
• Check Evaporative Emission (EVAP) System

 

[<tuffty/>]

Vacuum leak could be the cause of that... check Block 032 of the Engine group when the engine is warm and idling

<tuffty/>

 

[finesse]

ok thanks will do, what range of figures would you expect?

 

[<tuffty/>]

Should be as close to 0% (+/- 5%) as poss... first value is idle trim and is the one I think this relates too... if its adding fuel (positive number) I would suspect a substantial vacuum leak... probably a split pipe (or pipes normally) under the inlet manifold. Check any pipe from the inlet manifold following them back as far as they go for splits etc... they may not be obvious so make sure you look all around the pipes...

FYI, the fuel pressure regulator is the round bit on the end of the fuel injector rail. This too has a vacuum pipe and is prone to splitting... this could be the cause of this issue by creating a vac leak as well has not being able to control fuel pressure due to the vac pipe controlling it having a vac leak...

<tuffty/>

 

[badger5]

also look at block 001 on idle and cruising throttle, full throttle etc..
block 031 is lanbda spec and request, and you will see ecu's compensation to achivee this via block 001, so if leaks are present then you would expect to see 001 have largish numbers.
also log maf output on 003 incase its shagged.. and under reading. (usually pops a lean code not rich tho)

It could also of course be a mis-readin lambda

log some stuff as suggested and report back

 

[finesse]

Excellent! Thank you, will report back.

 

[basil brush]

sorry to resurect an old thread but thought it better than starting a new one ?
did you sort this ?
i only ask as i have a 1.8t flooding on cold start up and i have just found 2 massive splits in the breather system (under intake manifold) and wonder if this could be related ?
also finesse are you a vcds owner in southminster ? if you are i would like to cross your palm with silver to use you and you vcds
regards marc