Some Qs about Fi.

[Taipan]

Hi All

In my attempt to understand the black art that is Fuel injection, can anyone answer the following for me.

Does setting the CO at idle alter the mixture across the entire rev range?

If the throttle bodies were out of sync, what effect, if any, does this have on CO readings?

Do motronic chips adjust just the mixture or ignition timing as well?

Many thanks.

Dave.

 

[littleredrooster]

Hi All

In my attempt to understand the black art that is Fuel injection, can anyone answer the following for me.

Does setting the CO at idle alter the mixture across the entire rev range?

Didn't think there was any adjustment possible? (I assume 1150)

If the throttle bodies were out of sync, what effect, if any, does this have on CO readings?

Not sure

Do motronic chips adjust just the mixture or ignition timing as well?

Mixture and timing, as far as I understand

Many thanks.

Dave.

The Motronic operates in two different modes: tickover and just above it is in 'closed loop' which uses the lambda probe to analyse exhaust gasses and adjust the mixture in real-time to achieve the required CO. Above tickover, it ignores the lambda and reverts to a fuel-map which is determined by the position of the cat-code plug jumper wire. Several different maps are preset into the motronic for differing circumstances - e.g. cat / no cat; 98 RON fuel, 76 RON fuel; standard rev limit, extended rev limit (as on 'S' models)

 

[Frank Warner]

Which bike/motronic are you takin of?

The real answer is - only bosh & possibly bm know.

Older motornic systems had no lamda sensor - so were open loop all the time. Newer ones have knock sensors too - so they can adjust the timing of the spark.

And at least some of them can use the lamda sensor to do fuel adjustmants above idle - usually for constant throttle settings as accelleration is usually too quick for the sensor to follow it.

 

[Taipan]

Sorry, I should have said, its an 1100 (non cat model).