Thought it best to start a new query. So following on from my previous thread, ive booked the car into Stealth next week to sort out the issue with the VSS and turn up the power a touch. I have done approx 700miles in the car now and theres a couple of things have cropped up; I have a hesitation or shuffling under 4k,bit of a google pings it as a common problem but thinking it could be related to the below issue... The fuel trimming isnt active. I've fitted resistors to sort out N112, N80 & SAI relay. The only fault codes I now get apart from secondary lambda & VSS are; 18080 - Coolant Fan Control 1 P1672 - 004 - Open or Short to Ground - MIL ON 16414 - Oxygen (Lambda) Sensor B1 S1: Heating Circuit P0030 - 004 - Malfunction / Open Circuit - MIL ON 16434 - Oxygen (Lambda) Sensor B2 S1: Heating Circuit P0050 - 004 - Malfunction / Open Circuit - MIL ON The values in measuring blocks 32 & 33 are set solid at 0% but lambda values do react. I've checked the MAF and the airflow matches expectations. Any ideas why the trimming isnt working?
I would have thought that the fuel trim is tied into the Lambda's as that's what they are there for. Have you plugged them all in or are you only running the front 2 and are going to code out the 2nd bank?
The rears aren't fitted, but they're only there for OBD Cat failure detection. I don't believe they loop into the engine fuelling.
I stand corrected, But with an MIL ON thats an engine check light so it's restricting something i would say. I had mine coded out from day one and not 1 problem
Its a fair point, I'm not sure why it's pinging a heating fault. Kind of don't want to spend 180 on a pair of lambdas to find out if its them.
Did you read the measuring blocks 32 & 33 Before or after clearing fault codes ? If you cleared the faults that will be why it is a 0% as doing this resets the fuel trims
I had cleared the codes, but have done 30miles since. I thought 33 was short term adapts, 32 being longer term idle & load adapts. Its certainly running rich, had a new backbox and the tips were sooty within 100miles. It's just had 6 new coil packs & plugs.
If the Trim Values are both for long and short term (normally in MVB 32) are still at 0% it's not been monitoring the trims as they are never at 0% unless laboratory conditions on a bench and the wind blows the right way!! could a be and likely not generating a readiness code, until then as I recall it doesn't start checking the systems fully cos the rear lambdas
A good point. I checked the readiness codes and itis flagging errors with oxygen sensors so ill investigate that further.
So ive been back through the wiring and its correct, one question.....im getting 12v on the heating circuit when the engine runs but not with ignition on. Is that correct? According to the wiring diagram the power feed should be ignition on, wondering if that is the cause of teh fault code which in turn inhibits functionally. I've order a pair of lambdas, but just wanted to check.
are you testing across the 2 lambda heater pins? I think the ecu switches the earth on and off when required. also the lambda power wire is on the fuel pump relay output so it will only be live for 1st few seconds while pump is priming but not after that
Thank you once again. I'm measuring the bl/ro feed which does as you've indicated, show voltage when the pump primes and engine is running. So checking against the wiring diagram, that is correct. I will just double check the wire back to ecu are into the correct pin before fitting 150's worth of new lambdas!
