Thanks Mitch, That is the most useful description of EFI tuning I have read to date. I will print it out, and put it in my manual. Do you do this for a living? Sorry about the double post, the first one did not show up for awhile, and I thought it got lost in cyber space.
Sam

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I had a discussion about O2 sensors with the Drakes last night.

As I have been suspecting when tuning my own cars, any O2 sensor (WB or NB, but especially NB) can read lean when the mix is way too rich. The engine starts to miss when too rich and leaves more O2 in the exhaust. Raw fuel may also hit the sensor itself depending on where mounted.

I made a breakthrough on my 64 tuning while driving down to Charlotte yesterday - had it 20-25% too rich!! I got on a track over the last few months since reringing the motor where I thought it was lean based on O2 readings, then kept richening. The more fuel I took out of it yesterday, the better/faster it ran. MPG picked up at least 15-20% even though I had cruise mix tuned correctly. I believe the car is faster than ever, but will have to hit the strip to verify.

It is not hard to get off and keep going in the wrong direction. The Drakes have done this to be protective of the motor too, then tried leaning out substantially and picked up a few tenths at the strip.

Lou

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Home of Slant6-powered fun machines since 1988

Anytime you have a missfire the O2 can read lean, it does read O2 not fuel & if the fuel didnt burn the O2 didnt either.

But these guys dont lie.

http://www.dragstuff.com/techarticles/r ... plugs.html

http://www.dragstuff.com/phpBB2/viewtop ... fdfd467cd7


They cant be fooled like a O2 sensor can. Read all including the topics & pics listed at the bottom.



Jess

NOW this is what I am talking about! FUNdamentals of good practice. This also goes in my tuning manual. We might end up making a sticky note, or article based on what comes of this thread
Sam

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NOW this is what I am talking about! FUNdamentals of good practice. This also goes in my tuning manual. We might end up making a sticky note, or article based on what comes of this thread
Sam

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