Motronic and Injector Pulswidth

[Billman]

Hi,

does anybody knows what is max pulswidth that the motronic runs the stock RS2 injectors?

cheers

[S2central.net]

Well - what do you mean there exactly ?

The max pulsewidth is theoretically largest at the slowest engine speed which I guess isn't what you want.

With VAG-COM you can get the injector opening times logged as you drive.

Don't forget the time available for fuel injection pulse gets shorter with increased engine speed and you need to factor in approx 85% duty cycle on the injector plus some millisecond opening and closing time. Anyway VAG-COM is good for this info.

The raw data can be extracted from the Motronic maps, but that doesn't tell the whole story as there is compensation for temperature and WOT effects.

[Billman]

Yes that is what i ask. Is there any max PW number the motronic can handle (or that we know of)?

It would also be nice if we could know the AFRs the stock ADU chip runs with (under normal conditions on warm engine without any compensation).

[S2central.net]

You can safely expect that AFRs in cruise conditions on warm engine to be around 14.7:1 because of closed loop lambda control... AFAIK - the VEMS and other aftermarket ECUs will do that automatically.

At WOT, you want to see AFR in region of 10-12 : 1 and you'll need to program the WOT maps in aftermarket for that, unless they have adaptation capability with a wideband O2 sensor.