m20b23 swap from k-jet to motronic

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Dammizi
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Joined: Tue Dec 16, 2014 12:40 pm
My E21(s): '81 Euro 323i

m20b23 swap from k-jet to motronic

Post by Dammizi »

Hi, so after finally rebuilding my m20b23 after 15years lying on the floor in my garage with a bent con-rod, now it's fully rebuilt installed and ready to run.

in progress of rebuilding the engine I decided to scrap the old fuel injection system that had been so long unused and installed a motronic 1.3 EFI setup. now the setup was off a running m20b20 and after I installed it on the b23 it seems to be running reasonably well but i'm having problems with hesitation under acceleration and lack of power in low rpm's

presumably this is because the fuel and ignition maps are designed for a 2L engine not 2.3L so what I need is for someone to tune my ecu chip with a new map for the 2.3 setup. I know this is possible but I dont know from where I can purchase a modified chip for the 2.3 and have never done anything like this to an ecu. do any of you know from where I can buy a modified motronic chip for the 2.3 since all 2.3's were originally either sold with k-jet or LE Jetronic not motronic :/

have I done a big mistake in using this setup on my b23 or is there a light at the end of the tunnel somwhere??? :hammer

thx for your help guys :)


pandemonium001
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Re: m20b23 swap from k-jet to motronic

Post by pandemonium001 »

tune your own eprom.

http://tunerpro.net/

try a m20b25 173 DME and AFM and inlet see if that helps?

are you running 2.0 injectors?

adjust fuel pressure to try and tune, adjust afm spring?

WAR chip?


just some ideas
Dammizi
Upcoming E21 fanatic
Posts: 74
Joined: Tue Dec 16, 2014 12:40 pm
My E21(s): '81 Euro 323i

Re: m20b23 swap from k-jet to motronic

Post by Dammizi »

Yes, its currently running 2.0 injectors. If I knew what I was doing I would happily tune my own ecu... But all those numbers in tunerpro mean little to me :/

How will adjusting afm spring help? Under any throttle the afm door opens immeadly with little resistance.

And also im guessing that running 2.5 ecu and intake might help it getting closer to running in ideal conditions but still it is not going to be running perfectly since its a. 2.3 not 2.5....
Dammizi
Upcoming E21 fanatic
Posts: 74
Joined: Tue Dec 16, 2014 12:40 pm
My E21(s): '81 Euro 323i

Re: m20b23 swap from k-jet to motronic

Post by Dammizi »

Btw what is there special about running the war chip apart from it being pre programmed to run on maf instead of afm? I know it is programmable, but are not all chips off the 173 ecu programmable?
pandemonium001
E21 Pro
Posts: 528
Joined: Sun Oct 07, 2012 1:19 pm
My E21(s): E12 535i T (ish)
Location: Scotland Ayrshire

Re: m20b23 swap from k-jet to motronic

Post by pandemonium001 »

Dammizi wrote:Btw what is there special about running the war chip apart from it being pre programmed to run on maf instead of afm? I know it is programmable, but are not all chips off the 173 ecu programmable?
Yes all 173 ecu's can have the chip replaced with a re-programmable chip, but war sell them with a base tune.

Does not have to be programmed to go MAF, that was just the next step for them. They may be able to send you a package setup for a 2.3.

but probably why you cant find an aftermarket chip is there is no demand for the 2.3 most people would opt for 2.5 or 2.7 eta.

or just sell the 2.3 and put m50b28 in with loom and ecu.
Dammizi
Upcoming E21 fanatic
Posts: 74
Joined: Tue Dec 16, 2014 12:40 pm
My E21(s): '81 Euro 323i

Re: m20b23 swap from k-jet to motronic

Post by Dammizi »

only reason I kept the 2.3 is that here in malta classic cars are tax exempt and also insurance is greatly reduced, but to qualify as a classic you have to keep the car at least with an engine that the model car came out with and the 2.3 was the best option available in this case...

also the biggest problem I am finding is as most of you know the 2.3 was never using motronic so there is no base map for 2.3 on motronic if someone has done it he has had to start from scratch, and till now I know of no one who has done this...

do you think that it would be really hard to just learn how to program the ecu myself using tunerpro? i am quite comfortable using most software so I guess if I can find a good tutorial for understanding how to work around tuner pro and understand what all those numbers actually relate to I should be getting somewhere right?
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