Renault Clio 1.2 8v 1996 runs too lean.Archived Message
Posted by Peter Holland on November 16, 2007, 10:44 am
Car is fitted with a Magneti Marelli ECU, part no PLF 7700107694 (This is the only number that anyone recognises, there is no IAW number on it) CO 0.05, HC 235, CO2 11.5, O2 6.03, Lambda 1.35. O2 sensor voltage 35mV (new sensor fitted as old one wouldn't drop below 150mV) MAP shown on live data - 470mb, measured vacuum - 17 in/mg. Checked extensively for air leaks. It did have an air leak around the servo but this has been fixed. What confuses me is that the live data shows long term fuel trim at idle and part throttle as -100%,surely this means its trying to reduce the fueling.....? STFT reads 91. I suspect a possible ECU defect, so I sent the ECU away but it was returned with no fault found. The company who tested it didn't have an answer to my query regarding the fuel trim figure. I'm stuck now!