2006 STI plug in M800 idle problem

[cammck510]

Hi All,

FWIW, I'm following this one up for a good friend who is trying to help another 'good friend' with his 2006Sti and the M800 plug in. (i.e. not my problem just trying to help another MoTec buddie )

Situation is this;

Stock 2006 STI with the exception of larger fuel pump and turbo (un-molested long motor including injectors)

With factory ecu plugged in, idle Lambda = 1.0 and everything is happy

With M800, idle lambda is .78-80 (rich) - but when you try and trim it out on the fuel map it will drop a cylinder.


We have considered this;

Factory Ecu can control fuel pressure - M800 doesn't

Therefore at idle a higher fuel pressure with same injector duration means we have to compensate on the fuel map

Idle voltage and Injector dead time compensation - 13.8V and even then if we adjust it on the fuel map it shouldn't be a problem, why would it then drop a cylinder?

Wiring/Fuel system - all good with factory ECU, only an issue when plugging in the M800

Lambda measurements - Motec PLM

'Buddie's' have discussed with Ross with limited success (not having a go at you Ross, just asking for more suggestions or direction here because we are lost for ideas).


Many thanks

Cam

[stevieturbo]

Is it dropping fuel or spark when it loses a cylinder ?

And which cylinder ?

Obviously the base map supplised is only a base map, and tuning will be required for it to run correctly.

Fuel pump control is a non-issue...unless the fuel pump is getting turned off. And I'd doubt the OE ecu can control fuel pressure. The mechanical FPR does this, with no connection to the ecu whatseover.

[RossB]

This has been resolved now. It turned out to be a combination of things. The Cam Control settings were not correct, I was told that the plugs on one bank were black while the others were a normal colour so I assume that the cams were doing different things on each bank.

The other problem was the injection timing. To idle at lambda 1 the EOI timing needed to be set at 450 degrees otherwise the engine would not idle smoothly.