• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

lh 2.4 conversion questions


Feb 27, 2005
I have questions regarding the LH 2.4 conversion I am doing on a 1984 242 turbo. I can't find an 84 diagram that shows which fuses are connected to each other to tell where to connect my constant power (red wire), thick red/yellow (fused switched power?), blue wire (switched power to 15R on ignition switch?), and small red/yellow switched power also.
The wires on the coil, there are wires in the stock harness that went to the coil. Do those get reused, or just only hook up the wires to the coil that are part of the LH harness? (plus the tach wire).
With the engine at TDC #1 the distributor rotor is not centered on the little notch mark on the housing. Does it matter? I know the firing is all in the ECU & ICU & crank trigger. The the rotor isn't way off, part of the tip is probably still under the terminal.
Thanks for the help.
Does this belong in performance??
Last edited:
The greenbook has the fuse panel diagram near the front. Here it is below for the '84 240 showing which circuits are joined. Hope it helps a little.

If you had my LH 2.4 conversion harness I would tell you to eliminate your old engine and ignition harness, since the new one has every circuit needed. But I don't know if you're making your own harness or what. If I were building one from a used harness, I would not use any part of an old k-jet engine or ignition harness.

Dave B


  • 240_1984fusepanel.jpg
    191.6 KB · Views: 38
You might need to re-pin your ignition switch connector to make sure that wire that goes to that stays hot while you crank motor, if not it won't start.

There are two wires I used on my install on the old harness that hook to the grey plug by the coil, one is the tach, like you said, the other is power to the coil I believe. I know it won't start or run if I unplug it.


Constant power to the ECU is it's own 30 amp fuse there by the battery like in my pic unless you have the later harness.

Turning the distributor does nothing to adjust the timing, but yes the rotor needs to be sparking plug one at top dead so it needs to be close. I was off on my car before and when I revved it up it would cut out. Turned it back a bit and then revved up.

Wire 1: Thicker (12ga?) Red/Yellow- Power OUT TO Fuel Pumps.
(Wire 2:) Thinner (16ga?) Red/Yellow: Power FROM fuse to Heated 02. (Vehicle will start without this wire connected)
Wire 3: Blue: Ignition ON signal.
Wire 4: Blue/Black: Signal fom back Speedo (optional. You will get high idle after freeway runs without it. No big deal.)
Wire 5: Power up ignition coil with switched 12v. ( i suggest adding it to 2 wire plug. One wire is yel/red. Other is blue. By adding 12v to this wire, you are powering up the coil and the powerstage)
(Wire 6) entire LH System/Fuel Pumps gets power from a RED fused wire from the battery. At least on 1989-1990. Later model wiring harness is different. Sort thru other guy's posts or look at wiring diagrams to figure it out.


The blue switch while cranking power wire I hooked to the wire that goes to the starter solenoid.
Last edited: