Toyota Avensis 1.8 1998 7A-FE - On starting, sometimes backfires #Archived Message
Posted by geoff taylor on April 12, 2007, 5:08 pm
Original customer complaint- When trying to start the vehicle it would sometimes miss starting and backfire.Also it would give the impression that the ignition timing was advanced,rather like if a HT lead had been put on the wrong plug.
When vehicle came into our garage this fault was not present but other member of staff has experianced the fault.I then checked the DTC Blink codes.2 codes were present. 1-2 CMP/CKP and 3-1 MAP.I suspect that out of all these codes that camshaft position sensor is the most likely fault.Then I have checked the resistance which seems to be ok.
I then decided to erase the fault codes,this was comfirmed by MIL light flashing regularly 1111,I then started the engine and straight away noticed that the MIL light came on and stayed on.I then checked fault codes again,which this time a new code had appeared.2-1 Lambda sensor.But both the original fault codes had gone and did not return. I then checked emissions which were perfect.I then checked the heating element of lambda sensor which is open circuit.
Question 1- why would this fault come on after the other codes had been erased?
question 2- would a fault on a lambda heater cause the MIL to come on?
Due top the cost of the lambda sensor £220+vat and not being convinced that this would cause the original fault I would appreciated any help on this matter before going ahead and ordering a new lambda sensor. many thanks geoff taylor.