martin1512
Well-Known Member
sounds like you have an engine that is running rich. My main suspects would be either a faulty MAF sensor or a Lambda sensor. Do you know anyone with an OBD reader that they can plug in and check for any fault codes? As for the LPG system, have you checked for voltage at the switch?
classic kev
Well-Known Member
If its hunting on idle then you probably need to remove and clean the stepper motor. You will probably find the ignition timing has been fiddled with to account for the LPG so if LPG isn't working I might think about resetting timing.
I agree MAF sounds like a prime suspect for running rich. I would also check temperature thermistor with a multimeter.
Lamda sensors could also cause rich running but I think I would start with the MAF, stepper and ignition timing.
If you do a search there are lots of similar threads.
I agree MAF sounds like a prime suspect for running rich. I would also check temperature thermistor with a multimeter.
Lamda sensors could also cause rich running but I think I would start with the MAF, stepper and ignition timing.
If you do a search there are lots of similar threads.
check the voltage from the AFM - although you can't adjust for cat equiped cars.
Blue/red CO trim value 1.8 for cat cars
Blue/Green Air flow signal- should be .2-.7 volts (no air flow). Tick over on the 3.9 is about 1.7 volts
do you have the correct tune resitor for the ECU - should be White 3900 Ohms
Blue/red CO trim value 1.8 for cat cars
Blue/Green Air flow signal- should be .2-.7 volts (no air flow). Tick over on the 3.9 is about 1.7 volts
do you have the correct tune resitor for the ECU - should be White 3900 Ohms
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classic kev
Well-Known Member
You can adjust the MAF on a cat equipped car but because the ECU uses the input from lamdas it ignores the setting on the MAF and only responds to lamda and this is why it is often said you can't adjust if running cats.
The tune select resistor you mention above is for non-cat cars. The correct value for european catalyst cars is 3k9 Ohms and should have a white wire.
