Slight ruff idle

[Jezza-7]

After about 30 seconds it wants to cut out, even after a long drive.

I have noticed this since i did the boost return mod. I have been thinking what could cause problems.

I have a new lambda sensor as the car has done 100k and thats due to go on which could be one reason but i was wondering if it has anything to do with spraying PTFE grease into the charger and it has gone all over the MAF sensor. Could this be causing it to run ruff?

[hayesey]

There is no MAF on a g40 so it ain't going to be that. Since you mention it started when de-wedging the throttle body, i'd start by making sure the holes in the throttle plate are properly sealed

[Jezza-7]

No it was after the boost mod.

I ment the co pot in the boost pipe, sorry.

[hayesey]

Well the co pot can't get gummed up as it's just an adjustable resistor but the inlet temp sensor that is in the same unit could be, give it a spray with some degreaser.

[Jezza-7]

Will do, Cheers.

[Etches]

How do you check the current on the co2 pot?

[cheys03]

Copy/pasted this from Hayesey's diagnostic guide in the engine FAQ:

" For the CO pot, around 600-650ohms (measure across pins 1 and 3 if I remember correctly) is a good base setting, the car shouldn't be running bad like that.  But you need to put it on a gas analyser to set properly at idle.  "

[Etches]

So i presume this means taking the circuit board cover off then, cool ill have a check

[cheys03]

Shouldn't have to take the cover off...? I think it means to unplug the loom and measure the resistance across pins 1&3 on the CO pot, turning the adjustment screw until it's roughly 600-650ohms..

[vwmk3jon]

^^^ yup. Thought it was 550ohms tho?

[cheys03]

Yeah, I don't know myself. There's a discussion on it in the G40 Engine Diagnostic topic in the engine FAQ too.

[hayesey]

There isn't "a" setting for the co pot, why woud they bother making it adjustable if it always gets set to the same value? Set it to 550, 600, 650, what ever you want, the only real way to set it is to get it on a gas analyzer.

[DKnight]

as said above, i put mine on gas analyzer for first time in owning G40's for many years and the difference was massive, any garage should have the capabilities to do this, and it is just a 10 minute job, but just make sure they know what they are doing in regards to adjustment and readings.

[Jezza-7]

Right, now that i have changed the lambda it seems a little better. I cleaned the co pot with some gunk sprayed on it. There wasnt much oil on it in the first place.

It still struggles though. I will try upload a vid.

[Jezza-7]

This is the link if anyone could help?