running very rich.

[gruffalo]

car is misfiring when I put my foot down and is running really rich.

One Lamda is unresponsive but as Lambda control is turned off on the ECU could this be the problem, every thing else is reading perfect?

Injectors, coils packs, leads every thing else is new so should be OK.

[QBee]

The engine is new too, isn't it? Sorry, but take it to an expert before your next track day?

[scotty_d]

If the lamdas are not working it will run very poor bellow 3000rpm, over 3k they go open loop but they do make a massive difference at bellow 3k.

[N7GTX]

gruffalo said:

car is misfiring when I put my foot down and is running really rich.

One Lamda is unresponsive but as Lambda control is turned off on the ECU could this be the problem, every thing else is reading perfect?

Injectors, coils packs, leads every thing else is new so should be OK.

Coolant temp sensor? Will cause rich mixture if stuck at cold.

A misfire results in unburnt gases which the lambda detects and more oxygen from the misfire will cause the ECU to increase fuelling.

By revving and lifting off can you get any movement on the unresponsive lambda?

[gruffalo]

N7GTX said:

gruffalo said:

car is misfiring when I put my foot down and is running really rich.

One Lamda is unresponsive but as Lambda control is turned off on the ECU could this be the problem, every thing else is reading perfect?

Injectors, coils packs, leads every thing else is new so should be OK.

Coolant temp sensor? Will cause rich mixture if stuck at cold.

A misfire results in unburnt gases which the lambda detects and more oxygen from the misfire will cause the ECU to increase fuelling.

By revving and lifting off can you get any movement on the unresponsive lambda?

Engine coolant sensor spot on as is every thing else except Lambda 2 that does wake up for a while when I blip the throttle then it returns to zero, could be an ingnition lead issue I suppose making the lambda 2 read zero as it trying to weaken the mixture off due a misfire but the Lambda control is turned off so could the whole issue be caused by a plug lead and be shown up by Lambda 2 reading zero but why would a plug lead caused misfire make the whole lump run rich?

Guess it will be leads as the next thing to change, tried the air tem sensor first as that was causing a fault to be logged with the ECU, it is better but not quite right since. I know the leads are suseptable to heat and believe me she did get hot under the bonnet when on the rolling road being mapped so it could well be something that simple:-)

Thanks for the advice chaps, your are as ever very helpfull and much appreciated, got to love the Cerb forum.

Edited by gruffalo on Sunday 20th April 00:13

[N7GTX]

I had another play with mine last week as I felt a very slight misfire. Not a true miss but it just didn't seem right.
So, having already replaced plugs, leads and coils plus a compression check decided on a little experiment. The coils are wasted spark - i.e. numbers 1 and 4 fire together and 2 and 3 fire together (on each coil) - so I swapped number 2 with number 8 which are adjacent on that coil. And it ran much more evenly. So I suspect the primary spark is now going to the right cylinder at the right time rather than the secondary or wasted spark. Maybe I'm way off the mark but it has definitely worked for me.
I followed the original plug leads when changing them so assumed they were fitted the right way.

[Adambul]

It would be worth checking your fuel pressure just to make sure the fuel regulator hasn't packed up and is putting the full 5 Bar fuel pump pressure on to the injectors. I've got myself all set up to do this but not got round to doing it yet, primarily because my suspected over fueling problem is now resolved. My plan was to use the outlet from the filter under the rear near side wing rather than coming off the fuel rail, just because it was easier to fit a gauge.