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Piers1989
05-01-2019, 09:41 PM
Hi all,

I've had an issue with my car running very poorly on idle for some time now, and while its in Evotune in Durham for maintenance I asked them to take a look.

Jamie noticed that whilst the ECU is reverencing correct voltages from my wideband AFR to indicate lean / rich states, the fuel trim is always zero.
Initially he though the custom rom (Kenneth s 2.0) was the issue, but we have tried flashing back to the factory ROM and map as well and still the car is ignoring the lambda voltage and running lean on idle most of the time, up to 19+ AFR and sometimes after a start or rev, up to richness of 10 AFR.

In none of these situations does the ECU fuel trim change at all.
Seems to work fine in open loop, but in closed it basically just isn't working.

Jamie mentioned he has seen something similar happen once before where it was actually a blown component on the ECU, has anyone experienced this at all or have any other suggestions before I get the car back and remove the ECU for inspection?

Thanks