dannyblackpool

am i right in the thinking if a gauge is linked to a lambda on idle and at running temp the reading should fluctuate between lean and rich?? If it stays on lean have we a lambda faliure even with blips of throttle? if so could it make a car notoriously poor on fuel economy?? ie 20 mpg urban on a 2.0 8v?

rapidcossie

My car stays on lean at idle...15:1 i think

it has to be lean under normal ish( light/no load) condtions if we want any kinda fuel consumption.

dannyblackpool

i mean on a na engine ie under lambda 1

rapidcossie

sorry no idea about NA engines but surely they are not too different on idle?

dannyblackpool

no but iirc 15.1 isnt lean it is around lambda 1 ie ideal economy, turbos need extra fuelling on boost etc with amongst other things heat, ie i assume you will see 11s on full chat,something i assume a na golf gti should never see?on a narrow band gauge and sensor lambda 1 is around the middle of the reading range, if i plumb a gauge in its off the clock lean ie 17s maybe more, basically the end of the narrowbands reading range im no expert so may be talking utter bollox so fire suit on

dannyblackpool

anyone else?

tabetha

Yes it should fluctuate, BUT at a speed that you don't see!!
You sound like you have a very slow acting SENSOR, not unusual, it swings from rich to lean to give an average reading, called CLOSED LOOP.
The average should still be correct, so should read correct.
tabetha