Help a newb eliminate lambda on a 930

[Mikesavina]

Can anyone assist me with eliminating lambda and going back to full mechanical CIS? I purchased an engine from an 86 with lambda and I’m just about ready to do away with it. What all do I need? Also who modifies the distributor heads? Thanks for any help

[mark houghton]

Not all that simple....lots of stuff controlling the lamda system. If you just want to run open-loop without the system operating as designed, you can just unplug the oxygen sensor and tune your idle mixture a bit richer at idle to compensate.

Besides the relay under the seat, there's also a throttle position sensor and frequency valve that are part of the system. Your fuel head has been designed specifically with Lambda in mind, working in concert with the frequency valve to adjust mixture based on input from the O2 sensor and the TPS. When unplugging the O2 sensor, the frequency valve will stay at a steady state...open loop. If the freq valve is removed or unplugged the engine will run extremely lean. You would have to adjust each individual injector at the fuel distributor in order to compensate. Some people here have done that and may chime in here.

Personally, I've always ran without the O2 sensor plugged in.

[Mikesavina]

Originally Posted by mark houghton

Not all that simple....lots of stuff controlling the lamda system. If you just want to run open-loop without the system operating as designed, you can just unplug the oxygen sensor and tune your idle mixture a bit richer at idle to compensate.

Besides the relay under the seat, there's also a throttle position sensor and frequency valve that are part of the system. Your fuel head has been designed specifically with Lambda in mind, working in concert with the frequency valve to adjust mixture based on input from the O2 sensor and the TPS. When unplugging the O2 sensor, the frequency valve will stay at a steady state...open loop. If the freq valve is removed or unplugged the engine will run extremely lean. You would have to adjust each individual injector at the fuel distributor in order to compensate. Some people here have done that and may chime in here.

Personally, I've always ran without the O2 sensor plugged in.

Thanks for the info. It’s the most helpful info I have received so far.
None of it sounds like all that much fun for someone that doesn’t really understand the CIS as well as I would like to. I’m having a tough time deciding what the best path is.

[T77911S]

you need to send your fuel head to larry at flowtech.
he can modify it run without the FV.

i have one from him and love it. no electronics for my 86

[RarlyL8]

Larry is 8 weeks out on rebuilds right now, I keep them in stock along with adjustable WURs.
Swap out the -145 FD for the modified version and the -153 WUR for one that is adjustable and you're done.

[Mikesavina]

Originally Posted by RarlyL8

Larry is 8 weeks out on rebuilds right now, I keep them in stock along with adjustable WURs.
Swap out the -145 FD for the modified version and the -153 WUR for one that is adjustable and you're done.

My stuff is on its way to you in the AM. Took it off and boxed it all up


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[billjam]

Click on the link for the wiring diagram called "1986 930 engine wiring diagram, emissions delete (PDF)" in this thread. It shows which devices and wiring can be removed from an '86 to effectively eliminate the emission controls.

[T77911S]

you can remove or just disconnect the O2 but you still need the FV unless you get the FD modifed.
i have NO electronics under my seat. i even removed the speed/rev limiter and use the rev limiter on my MSD. i am also running the aluminum FD.
you can just go with a cast iron FD but i wouldnt

[Mikesavina]

Originally Posted by T77911S

you can remove or just disconnect the O2 but you still need the FV unless you get the FD modifed.
i have NO electronics under my seat. i even removed the speed/rev limiter and use the rev limiter on my MSD. i am also running the aluminum FD.
you can just go with a cast iron FD but i wouldnt

I am having the FD and WUR modified. So I can disconnect my FV correct?


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[T77911S]

you sending it to larry.

anybody else that does it is just a middle man that pays larry to do them.

[RarlyL8]

"Just a middleman" is pretty insulting. Amazon is a middle man. When was the last time Larry was on this board helping people with their 930 questions? Never. I used to rebuild all this stuff myself years ago until I found solid folks that could do that basic work, leaving me time to concentrate on modifications and tuning. Good luck getting ahold of Larry or BL, Larry is semi-retired and BL has a full time job. Both are consistently 6-8 weeks out. And FWIW, Larry doesn't build anything, he pays people to do that for him.

[Black_Hat]

I have ordered many things from Brian @ RarlyL8
and have gotten quality parts, 100% customer service, advice , sounding board service same for TurboKraft & EverGreen Turbo.

Please support Guys like these as they grow fewer by the day.......

[T77911S]

you send everything out to someone else that the people can deal with directly.

middle man....

just trying to save people money

no
i dont care for you.
i tried to support you but
you left my car sitting for over 3 months when you sent my WUR out to be modified by someone else and you lost it. i never had the confidence you were doing anything to get me another one other waiting to see if you could find it. i was stressed over not knowing if was getting my WUR back. i asked for a reduced price due to my inconvenience and you cried poverty.

[RarlyL8]

Go direct or go to me, same price. Lead times vastly reduced.
I didn't lose your WUR. Leask went off grid for about a year due to personal issues which left me hung out on several WUR's including yours. I replaced yours with one of mine at my expense. Had you gone direct in this case you would never have seen your WUR again. Not the typical situation by any stretch and I hate that it happened.