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b230ft into '79 244, wiring?

benknowsbest

benknowsbest

New member
Joined
Nov 3, 2010
Location
Canberra, Australia
hello,
im planning an engine swap for my 240, ive managed to source a b230ft from an 87-88 740t to pop in. this is my first time doing anything like this so there will be a lot of head scratching along the way im sure, but the main confusion at the moment is what to do for the wiring harness?
the donor engine runs lh2.2, the car its going into currently has a b21a in it. ive done a lot of googling but its hard to find information for this specific combination.
is it simply a matter of grabbing an lh2.2 computer and harness from a 240 or will i have to splice something together from a 740?

thanks in advance, and sorry for the dumb questions.
 
The 2.2 harness from the 240 uses the chrysler ignition system and not ezk117 like the 740 so at minimum, you'd have to cut and splice in the wiring for the hall sensor and ignition module.

The 740 harness is a hodgepodge of wiring and I wouldn't recommend using it unless you have plenty of alcohol.

If you made the jump to lh2.4, you could take the ecus from a turbo 940 and harness from an lh2.4 240 and then you'd only have to add a crank sensor, and obviously the lh2.4 AMM.

The other alternative at this point would be to ditch Bosch altogether and go to an aftermarket EMS like megasquirt. http://www.useasydocs.com/ Diyautotune sells the microsquirt with a decent length of harness... Something to think about.
 
Last edited:
740atl said:
If you made the jump to lh2.4, you could take the harness and ecus from a turbo 940 and then you'd only have to add a crank sensor, and obviously the lh2.4 AMM.
Click to expand...

The 940 harness is just as "bad" as the one from 740, integrated into the rest of the car's wiring. Using lh2.4 and ez116k from a newer N/A 240 is the way to go, as all the wiring for the engine is separated from the rest of the wiring in the car.

It is ofcourse possible to cut an splice a 740/940 harness and get it to work, but getting it from a 240 is much faster and less work.
 
If you decide to go 2.4, I have a wiring harness I can make available. It came with the turbo kit I scooped up way back when I was still 2.2 intending to convert. That car got too rusty, so I got a 2.4 car and am hoping to be turbo today or tomorrow.

As such... extra harness.
 
eabras said:
The 940 harness is just as "bad" as the one from 740, integrated into the rest of the car's wiring. Using lh2.4 and ez116k from a newer N/A 240 is the way to go, as all the wiring for the engine is separated from the rest of the wiring in the car.

It is ofcourse possible to cut an splice a 740/940 harness and get it to work, but getting it from a 240 is much faster and less work.
Click to expand...

corrected. had 5% left on the laptop. Agreed 740/940 harness is a terrible thing and a terrible idea to chose.
 
ok cheers for the advice guys.
still unsure weather im going 2.2 or 2.4 yet, it'll probably get MS'd at some point - will one be easier to deal with than the other?
from what i understand i will need some kind of diff sensor business for the speedo if i go lh2.4, will the current speedo work with lh2.2 or will i have to change it regardless?

thanks again.
 
I used LH2.2 and Ezk 117 in my 242. I bought a new engine harness and spliced in a 240 Ezk harness, it was about 12 wires in total. You don't need to worry about the speedo if you go 2.2 either.
 
Regardless what you do, starting with a 240 harness will make your life easier. It comes out as a complete unit. If you want to stay simple, there's nothing wrong with lh2.2 as long as your goals are modest... it goes without saying that you must use 740 turbo lh2.2 ecu and turbo ezk117.

At a later date it is still a great template for a jump to aftermarket ems.
 
2.4 really needs speedo signal or you will have a high idle and possible part throttle surging. Benefit being you can install larger than stock injectors!


2.2 isn't that hard. Wiring diagram and DVOM skills are all that will be needed.
 
sorry to bring up an old thread, things are moving very slowly.

So I've decided the go lh2.4, and have since acquired a late '89 wagon with all the parts I need. Now as far as I'm aware the cluster is completely different, is it possible to swap just the lh2.4 cluster into the early dash or am I going to need to swap the entire dash to the later style?
 
Later dash bolts in and has all that room for gauges or gadgets. You have all the parts. Swap the rear axle from the later car as well. That way you have the speedo sensor for LH2.4
 
If you use an LH2.2 throttle body, you can use that to set the idle speed. This eliminates the need to swap the dash and the axle.
The lh2.2 one bolts on, all you have to do is swap over the lh2.4 TPS. Simple simple.
 
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