HUB wrote:
Appreciate the comment. The thing that concerns me is more the tuning aspect and wiring. I'm still researching and waiting the response of a few people.
If I can't figure it out, I'll end up going with a platform I'm more familiar with, but I'm sure the swap has never been done.
Thanks,
What part of the wiring is tripping you up? Have you settled on an EMS yet (LH 2.2 and 2.4 were in the mix last I heard). Lemme see, Greg and I just wrapped up the testing for Dave Barton on the LH 2.2 conversion harness and I've just finished a 2.4 swap. Wiring isn't that hard to work out either way (so long as Dave has the dizzy wired correctly on the production harnesses!).
The Bentley manual for 240's goes over a complete harness check procedure for all EMS's that were on the car...and has complete wiring diagrams. Once you've made your call on what system you're running, then you have around 30 checks to do that fully check out the installation and ensure that it will fire and run properly. The engine side is easy (no really, it's just plugging in sensors and injectors/idle control assuming you've got a proper harness). That's the way you figure out the running side of things on these cars.
LH is pretty straight forward which is why everyone's sort of sitting and staring right now. Think of it this way, the engine has two separate but related control loops. One loop gathers information about engine state (coolant temperature, O2, mass of the air, knock, rpm signal for ignition (either through a real distributor on 2.2 or from a crank sensor on 2.4). Then it uses this information to run the ignition computer (EZK) and batch fires the injectors ECU or control idle. These are the on the "output" loop - at least in my head this is how it works. It's all as simple as it comes with respect to operation and in comparison to more modern systems.
Then there are either 3 or 5 wires that need to be connected to run power to things at the right time or to run the fuel pumps. They are even on a separate harness that goes in beside the computer connectors (either a 4 pin in the case of LH 2.2 or 9 pin in 2.4). That's it. In 2.2 you only need 3 wires and in 2.4 you need 5 of the 9 (unless you're running AC, and a bunch of other stuff you don't have). Now your car will need to have fuel pumps added (and supply and return lines - we've covered this) and you're going to need 4 extra fuses to run the EMS (not including the wire that goes directly to the battery). So you've got to decide how you're going to work out switched and constant power to these fuses...piggy back on what is there already or rewire the entire car.
For LH 2.4 you need a speed sender to send a pulse (and the computer doesn't care about the number of pulses per mile). You can do this any number of ways - I ran a converter from a Ford VSS (because I'm running a Ford T5 transmission) to a Dakota Digital converter to change the VSS sine wave into a square wave that I feed to the computer. This signal tells the computer two things. The first is it tells the computer when the car is idling and not moving (running, but no signal) so that it manages the Idle Air Control (IAC) motor properly and then also resolves when you're moving but have your foot off the pedal (as in coasting down a hill) - in this case it cuts the fuel to the injectors and the baby seals rejoice.