1980-83 e21 320i, oxygen sensor question

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tlake
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1980-83 e21 320i, oxygen sensor question

Post by tlake »

The 1980-83 e21 320i had the 3 way cat and oxygen sensor, but how did they do that with K-jet? How did they keep the fuel/air ratio at the 14.7:1 level precisely, when the fuel injection didn't have a computer :?:
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528i-1981
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Re: 1980-83 e21 320i, oxygen sensor question

Post by 528i-1981 »

The O2 sensor produces an electrical signal, so it has to be processed somehow.

This article mentions a controller of some kind that modulates fuel pressure through a valve that appears to be especially for K-Jet with lambda control :
http://cleanflametrap.com/kjetControlller.htm

I don't know much about E21s, and maybe you've seen this already. Just passing it along.

-Eric
(oo=00=oo) Eric
1981 528i Manual
tlake
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Re: 1980-83 e21 320i, oxygen sensor question

Post by tlake »

528i-1981 wrote: Sun May 03, 2020 1:01 pm The O2 sensor produces an electrical signal, so it has to be processed somehow.

This article mentions a controller of some kind that modulates fuel pressure through a valve that appears to be especially for K-Jet with lambda control :
http://cleanflametrap.com/kjetControlller.htm

I don't know much about E21s, and maybe you've seen this already. Just passing it along.

-Eric
Thanks Eric, yes I was wondering about this, given the 528i/633CSi/733i use the L-Jet computer to handle this. But of course there were lots of late '70s cars with K-jet.

It must get the job done, but I wouldn't think it would be as accurate as using a computer to do the job. Funny how cars as expensive as the Mercedes 6.9 and Porsche 930 only had K-jet and the 1975-80 Beetles had L-jet :!: :)
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Mike W.
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Re: 1980-83 e21 320i, oxygen sensor question

Post by Mike W. »

E21s with O2 sensors used a frequency valve. It modulated the control pressure going to the fuel distributor which in turn controlled mixture.
Mike W.



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tlake
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Re: 1980-83 e21 320i, oxygen sensor question

Post by tlake »

Mike W. wrote: Sat May 23, 2020 3:27 pm E21s with O2 sensors used a frequency valve. It modulated the control pressure going to the fuel distributor which in turn controlled mixture.
Thanks Mike, I always wondered how those cars worked, since the rest of the range had L-jet. :)
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Mike W.
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Re: 1980-83 e21 320i, oxygen sensor question

Post by Mike W. »

tlake wrote: Sun May 24, 2020 2:26 pm
Mike W. wrote: Sat May 23, 2020 3:27 pm E21s with O2 sensors used a frequency valve. It modulated the control pressure going to the fuel distributor which in turn controlled mixture.
Thanks Mike, I always wondered how those cars worked, since the rest of the range had L-jet. :)
It was cheaper to use and was more than adequate for passing smog and decent performance, hence it's popularity.
Mike W.



02 525ita. Wife's, aka grocery getter
02 530i. New to the fleet, 3 pedals.
08 Toyota 4Runner. 4WD vacationmobile. No enthusiasm, but it didn't leave me stranded or use any oil. Reserving judgement for now.
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