Hi there, I am sure I have read about this before, but have no forum search so here it is,
My 3dr had 10%CO for mot and was a failure, It passed last year, and I have altered nothing. After a run the plugs are black, and it does spit black soot out of exhaust, I tried connections on rear sensor on head with WD40 no difference, Any one any ideas, I have no misfires although the car is a bit hesitant to rev, which I presume is due to mixture. I think it maybe one of the sensors gone down, but would appreciate any advise before I start changing them

Darren

 

maybe the act sensor, the brown one in the inlet manifold, just a guess tho

 

more likely the blue ECT sensor (engine coolant temp) as these generally are more prone to failure and its this which determines whether the ecu fuels the car for cold or hot, if it fails it sees it as a cold engine which will run excess fuel.

 

https://passionford.com/forum/viewtopic.php?t=115550

i had the same prob dave emailed me how to read the rear blue sensor with a ohms meter think from cold it starts at around 3.00 then when hot will drop to 70 if it does its fine then try ur ecu


cheers jay

 

Just to let you know I checked resistance on sensors, appeared ok at cold but changed both blue and brown sensors anyway as they are old, left it running till fans cut in and out, then removed a plug, starting to go brown not black so think one of the sensors may of been problem but will confirm weekend when i take it out, but looks ok

Thanks

Darren

 

please say it was the one i said..... i never get nething right lol

 

one thing u have got right m8 is that 3rd proper m8 proper

jay