GM LT1 to AMC setup

[JeepsAndGuns]

Edited: to Eaglemark....
My dizzy now has the MSD large cap and adapter that lifts it up a bit. Also has the nicer wires to go with it, and MSD 6A ignition. If I do this dizzy conversion, can I keep this setup, or do I need to abandon it? Will the PCM take over functions that the MSD ignition currently does? I guess I dont fully understand how much control the PCM will have over ignition. I had assumed the PCM just sensed the firing of each cylinder and timed the fuel charge to match it-----and not actually "controlled" the ignition.

Not knowing anything about the msd ignitioin, but if the pickup coil in the distributor is like the stock one, you should be able to use it to trigger the GM system. I know the stock amc motocraft distributor works perfectly fine. I am using my stock dist. You will remove the msd ignition module and use only the distributor from the stock ignition system. The GM ecm/pcm takes over all timing controll, you simply program in what you want for timing. You will need to lock out the mechanical advance in the distributor (easy to do) and unhook and leave un hooked the vaccume advance.

[jeepboy45]

@JeepsAndGuns:

are you saying I need to go back to the factory brain unit? or does the ECM take the place ANY / ALL ignition control?
(both factory brain, or MSD)

DAMN!! I hope not... I just got finished getting rid of 2 miles of wiring associated with it, and rewiring to use the MSD for a much better ignition...

You said you use your stock motorcraft dizzy....... is your dizzy MODIFIED to be a hybrid combination, with GM components inside?

That would be my luck, I would do this upgrade (teamrush upgrade) and then 2 months later, have to UNWIRE the darn thing to go backwards!!! i hope not...

[Six_Shooter]

The MSD ignition can be retained, it may just get triggered differently than you might be thinking now.

Most of the time the points trigger will get used to trigger the MSD box, this allows the ECM to control timing with the benefits of the MSD ignition.

Laying out your goals for this engine will greatly help us give you a clear plan on what to use and how to connect it.

[EagleMark]

Laying out your goals for this engine will greatly help us give you a clear plan on what to use and how to connect it.

I agree. Someone sent him here for information as what he was getting elsewhere was mis information. I don't think he knows yet what his goals are other than EFI, he got a LT1 harness PCM and parts which is going to be a lot harder to do a conversion with than say 1227730. So it's been more of an information learning experience for him till this point. He may have enough information now to decide on what kind of system to build using parts he has an adapting others.

[FSJ Guy]

I can't help you with the LT1 PCM or harness. I've never played with one. However, I have used a 1227747 ECM and have since switched it over to the 16197427 PCM. Both of those computers will use the STOCK AMC distributor for ignition and timing control. As mentioned, you will have to lock out the mechanical advance and simply disconnect the vacuum advance. There are a bunch of writeups all over on how to use the '7747 ECM. It's easy to modify and simple to use.

The 16197427 PCM has a huge increase in the # of parameters that can be changed and adjusted. But if this is your first time programming a TBI system, it can be pretty intimidating. One of the biggest advantages (IMHO) of the '7427 PCM is that it has a faster data output and larger tables for spark and fuel.

With regards to keeping your MSD: The distributor is connected to the PCM. The PCM outputs a signal to the MSD. The MSD then sends spark to the engine (via the distributor, of course). Another advantage of the computer controlling timing is that you no longer need the Duraspark system.

BTW, this is all assuming you don't have something like a Prestolite ignition (points).

[EagleMark]

This covers wiring of MSD 6a in all applications including installing it in a stock EFI system.

[jeepboy45]

This covers wiring of MSD 6a in all applications including installing it in a stock EFI system.

This is the current MSD config:Wiringdiagram.jpg


I could be reading/understanding this ALL WRONG, but here goes...... The MSD module would get abandoned. Using hybrid dizzy as you mentioned earlier in thread, the dizzy would be connected directly to ECM, and ECM to coil?

My head is beginning to hurt!