G40 rough idle, suspect lambda ?

[Mk3Harry]

Okay folks after some advice and help, been experiencing some running problems with my g40 and from cold the idle is a bit jumpy but when its warm it is really rough and if you don't touch the throttle it will cut out. So I've tested the coolant temp sensor and the resistances all seem okay, tested the coil windings there all okay, checked the rotor arm resistance that was okay. So i did the trick of unplugging the lambda sensor and since doing that it ran fine, idled fine then when i plugged it back in it went back to rough idling and nearly cutting out. So my question is, is my lambda sensor at fault or because I've unplugged it and its running on the safe fuel map is it eliminating the sensor at fault ? Also is there anyway of checking that the lambda sensor is switching voltage ? Thanks, all help appreciated thanks Harry

[Jezza-7]

Have you read this?

http://www.polog40.co.uk/forum/index.php/topic,214.0.html

[Mk3Harry]

I have yes, and with the use of autodata and haynes manual i tested most sensors and all were okay, with the lambda probe unplugged it runs fine so would you say thats the fault

[Jezza-7]

Thats what i would put my money on.

[Mk3Harry]

Cheers for the reply, ill get one order asap and fingers crossed itll sort it. Thanks again !

[z3i]

Be prepared to get oxy acetalyne on it as mine was insanly tight after being in there so long, really had to get it bright red for any chance of it undoing

[Mk3Harry]

Ive doused it in freeing oil to let that set in and hopefully free it up abit, if not itll be bottles and a bit of brute force !