I'm in the process of a Fitech EFI install, and I'm thinking about what to do with the ignition system. Currently, the 5A has a standard Mopar electronic 2-wire distributor, Mopar electronic ignition box, ballast resistor, and standard canister coil. It works, sort of. I had been planning to keep this at least through the testing and tuning phase with the Fitech.
However, the Fitech ECU also includes the ability to run timing by controlling the ground side of the coil. The way this works is, you disconnect any vacuum advance, and you mechanically lock out the distributor to have zero advance at all. Then, you use a timing light to set initial timing to a spec shown in the Fitech computer, and from there a timing table in the computer controls all your timing from idle to WOT. This is, eventually, how I would like it to work.
There's a couple options for doing this, which leads to the big question:
-Buy a new MSD distributor that has screws for lockout and an adjustable coil phase.
-Buy a lockout plate from FBO, which installs into my existing distributor to disable mechanical advance. Unplug the vacuum line to disable vacuum advance.
-I have the old '87 Lean Burn distributor in a box somewhere. It is locked out from the factory because the Lean Burn computer controlled the spark.
The big question is, will there be any rotor phasing or timing issues using the lockout plate or the LB distributor? Is there a base timing offset built in to the pickup in the LB distributor? I know the early ones had two different pickups they toggled between, but the '87 should only have one. Is the pickup phased dead on with the rotor? Is there any reason it wouldn't work as well or better than locking out an advance distributor, either with a plate or via MSD's system? The goal is that the distributor basically turns into a very large crankshaft position sensor for the ECU, which perfectly describes the LB distributor, but I see a lot of people claiming it works and nobody who has actually used one in an EFI application. Does the Lean Burn distributor work the same as a locked out MSD would?
However, the Fitech ECU also includes the ability to run timing by controlling the ground side of the coil. The way this works is, you disconnect any vacuum advance, and you mechanically lock out the distributor to have zero advance at all. Then, you use a timing light to set initial timing to a spec shown in the Fitech computer, and from there a timing table in the computer controls all your timing from idle to WOT. This is, eventually, how I would like it to work.
There's a couple options for doing this, which leads to the big question:
-Buy a new MSD distributor that has screws for lockout and an adjustable coil phase.
-Buy a lockout plate from FBO, which installs into my existing distributor to disable mechanical advance. Unplug the vacuum line to disable vacuum advance.
-I have the old '87 Lean Burn distributor in a box somewhere. It is locked out from the factory because the Lean Burn computer controlled the spark.
The big question is, will there be any rotor phasing or timing issues using the lockout plate or the LB distributor? Is there a base timing offset built in to the pickup in the LB distributor? I know the early ones had two different pickups they toggled between, but the '87 should only have one. Is the pickup phased dead on with the rotor? Is there any reason it wouldn't work as well or better than locking out an advance distributor, either with a plate or via MSD's system? The goal is that the distributor basically turns into a very large crankshaft position sensor for the ECU, which perfectly describes the LB distributor, but I see a lot of people claiming it works and nobody who has actually used one in an EFI application. Does the Lean Burn distributor work the same as a locked out MSD would?