Am setting up a '93 B230FT using an LH 2.4 MFI ECU and EZ 116K Ignition Control Unit from a '90 780 w/B230FT. I have the Volvo wiring diagrams and have successfully built most of my own loom. Unfortunately, I'm currently many miles away from the car and the full diagrams and my two main sources of reliable info are in England on vacation away from email -- I only have a few copies of the main systems and don't have all my reference material as I try to figure this out over the break. I have a few questions I need answered, as I am getting down to the little details. Don't ask the strange mating of vintages between engine and ecu. Shouldn't matter, anyway.

1) What is the "Power Boost System Control Unit" (LH 2.4 ECU position 28 -- GR-R wire goes to 259/2 [PBS Control Unit] on the diagram). Obviously not a wastegate thing. What does this do and does it need to be hooked up on a race car?

2) Ballast Resistor: Can I use basically ANY 4 cyl Volvo model ballast resistor? I am under the impression that I can and that they made only one.

3) Fuel Injection Relay: Does it have to be specific to LH 2.4? Does anybody have the Bosch part number for this correct part?

4) Diagnostic Unit: Can anybody think of any model that was different that I should stay away from in case I go to the junkyard and get one? Yes, they are very simple and it's the wiring positions that matter, but still...

5) Power Stage: I am pretty sure that the EZ 116K ignition used a different power stage. Does this sound familiar to you?

I hate wiring. I have no problem with the mechanical stuff, but converting this thing over from Motec back to a standard Bosch FI hasn't been fun. Oh, and yes, this is going into a 240 -- but it's all custom wiring so I'm not too concerned about some of the normal interface questions we might normally have. Thanks in advance!