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Borewash on full throttle

EFI Tuning Fundamentals

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Is there ever potential to see bore wash at full throttle high boost/Medium boost, if so at what AFR/Lambda would you expect to see this occur. I appreciate this will be different for each application. Just trying to get a general feel for things

Hi Ryan,

I would not expect to see bore wash when under these conditions. The amount of fuel required to bore wash would cause quite an aggressive misfire and you would struggle with engine acceleration.

Might also be a problem the other way round, too - if there is an ignition problem there will be un-burned fuel effectively causing overfuelling.

Using lambda - oxygen in the exhaust - is a handy tuning aid, but a misfire, rich or not, will show a lean condition as there is unreduced oxygen in the exhaust gases. That's why, for serious 'tuners' I would recommend a 4/5 gas analyser as unburned and/or partially burned fuel will show up as hydro-carbons and/or carbon monoxide in the exhaust.

A leaking injector, or carb', could also contribute to excessive fuelling on a cylinder, or more.

Any particular reason you have this concern? Oh, the lower the block running temperature, the more likely fuel will condense on the bore.

Its was just a question I had in mind really, was always worried about running a car rich and coursing bore wash although I did have the idea in mind that this would never be the case. I'm just begging to try and get into tuning and it was just something which I wanted to clear up, the worry behind this come from a lot of engine claiming to fail when used tuning chips and running rich supposedly causing borewash.

Thanks for the replies and for clearing this up