Fuel trim, rich mixture?

[v12.24v]

Hello all,

after an engine rebuilt I am still not happy how my Griffith 500 is running. Camshaft (Kent 885), plug leads and the stepper motor is already changed. My feeling is, that the car runs to rich (exhaust fumes and black soot on the back). Lambda short term fuel trim is at idle at +70% more fuel and at long term fuel trim is at +100% more fuel. Throttle podi seems to work normal, also the air mass look like it works normal ( everything checked with rover gauge). Does anyone have an idea?

Thank you from Germany and I apologise for my English

[blitzracing]

So you are saying its adding fuel but appears to be rich. You will get this if the lambda probes don't switch, the ECU will keep putting in more fuel to try and get them to switch- But, if they never switch it should flag an error code. If the heater supply is missing the probes wont work, but have a read here:

http://www.g33.co.uk/img/fuel/14cux-fault-finding....

[v12.24v]

Hello Blitzracing, thank you for this good advice and link. Haven’t thought about the lambda heating... to check this looks easy.
The problem is a little curious, under load they work normally and short term switch from +/- 20%, but long term stays always at +100%... but at first i will check the lambda heating

Edited by v12.24v on Tuesday 20th October 08:39