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Just a question i had in my head. Back a few months ago i still had a clio 172 and when a induction kit was put on the car the mixture at WOT would be lean and if left like that would cause damage in the long run. The 172 ECU at WOT didn't have closed loop control of the air/fuel mixture, however it did so at part throttle :confused:. Now my question is now that i have a Astra coupe turbo does its ECU have closed loop control of the air/fuel mixture at WOT or is it similar to the 172 ECU as in its only closed loop at part throttle.

Cheers.

Chun.
 

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Closed loop uses the lambda sensor to adjust fuelling. Open loop should use the air flow meter or MAP sensor to adjust fuelling crudely. I'm surprised that it ran lean at WOT.
 

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Like Tom says closed loop is when the lambda sensors used to control the fueling. The lambdas ignored on cold starts, starting, full throttle and acceleration.

At WOT the MAP (rens use MAP sensors) would tell the ECU that there was not much vacum so it would chuck in fuel from a PREVIOUSLY programmed map that ren stuck in for a STANDARD car.

Out of intrest how lean was lean?

Some cars are better mapped than others for mods. The ones you see on the M way booting it with a plume of black smoke are set up rich so they usually tend to be ok.

What you wanted to do instead of getting an Astra was buy a 19 16V (ph1 of course) and then flick on the 5th injector at high revs that evens out the fueling nicely.

The Astra will be closed loop at part throttle and open loop like the 172.

As its a turbo vaux have probably done the setting up a la jap as its now know which means they will have set it rich to provide a nice large safety margin. So it should be fine.

Chris
 

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If it has an Air Mass Meter then it will adjust.

Also modern ECU's learn when in closed loop. This then alters how it fuels when in open loop.
 

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what does WOT stand for??

cheers

rodgerq
 
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