Installing an MSD 6AL on a 4AC engine

[dr.occa]

This is for those w/ a 4AC engine and wanting to upgrade their ignition system with an MSD 6AL.

The confusing thing for some (even for MSD technicians) is that it not only has an internal coil but it also has an internal igniter or is it an amplifier or both??? Well, we'll settle questions when we actually get to it and finish.

- pull the factory distributor...

4acMSD_01.jpg (110.5 KiB) Viewed 58 times

...and get to removing the cap.

4acMSD_02.jpg (98.11 KiB) Viewed 58 times

- what you'll find inside:

4acMSD_03.jpg (87.12 KiB) Viewed 58 times

*note: the vr sensor (magnetic pick-up) leads connect to the "igniter/amplifier" respective of their polarity.


-go ahead and remove the "igniter" by unscrewing the vr sensor leads from it first...

4acMSD_04.jpg (78.16 KiB) Viewed 58 times

...then unscrewing the lock nuts that hold the leads from the "igniter" to the coil...

4acMSD_05.jpg (99.29 KiB) Viewed 58 times

...finally removing the screws from the outside of the dist. body that holds the igniter in place...

4acMSD_06.jpg (73.28 KiB) Viewed 58 times

...and removing the igniter from the distributor completely along w/ the external connectors, etc...:

4acMSD_07.jpg (57.96 KiB) Viewed 58 times

- depending on whether or not your 6AL came brand new or used with connectors, crimp a pair of shielded female spade connectors (or males, or alternate male & female...what ever your preference) to the VR sensor leads as shown:

4acMSD_08.jpg (60.77 KiB) Viewed 58 times

- if you have them, attach male spade connectors to the COIL + & - leads (highlighted in the following picture red & green for the positive & negative leads respectively):

4acMSD_09.jpg (61.85 KiB) Viewed 58 times

We're already just about set to put the distributor back in.


- here, we created our own leads for the 6AL's magnetic trigger leads (you can purchase MSD's mag lead extension p/n: 8862) using similar wire color to that of the VR sensor leads (red to purlpe / white to green) & crimping the ends with the appropriate spade connectors.

4acMSD_10.jpg (60.51 KiB) Viewed 58 times

- next, we connected the MSD's black wire (not to be confused with the thicker black lead from the 6AL which is your battery negative lead!!!) to the COIL negative (-) and the orange wire to the COIL positive (+).

4acMSD_11.jpg (50.96 KiB) Viewed 58 times

we then notched the cap at the appropriate spots making sure that none of the wires find themselves in the path of any of the spinning internals. since we had a spare igniter and connectors, we sacrificed one of them to the snips and kept the black plug to fill the cavity that the now un-employed connectors once occupied. placed the rotor on, restabbed the dist the way we found it. re-installed the cap and gasket and bolted everything in place. then finished her up w/ the plug wires.

- completed the install by connecting the 6AL's smaller gauge red wire to an appropriate +12v ignition "ON" source and...VOILA!

she fired right up!

we noticed there was no longer a permeating residual fuel smell lingering and the idle was smoother.


install guide by erickz300 & dr.occa: July 7, 2009

[joel26]

nice great write up.. along with the helpful pics... +1

[mooreofit]

good stuff!

[CBR_TOY]

i wanna do this...

[Overdrift]

ive seen a lot of people use the older 3ac distributor with the external coil for msd.


very cool. too bad ive never seen a worth while increase in power from a msd ignition on a n/a car much less a 4ac womp womp I know I'm a downer debbie.

[dr.occa]

...very cool. too bad ive never seen a worth while increase in power from a msd ignition on a n/a car much less a 4ac womp womp I know I'm a downer debbie.

in eric's case, the 6AL was another addition to the schneider regrind, upgraded valve springs & weber 32/36 carb.

so it's not your "ordinary" 4ac.

[erickz300]

...very cool. too bad ive never seen a worth while increase in power from a msd ignition on a n/a car much less a 4ac womp womp I know I'm a downer debbie.

in eric's case, the 6AL was another addition to the schneider regrind, upgraded valve springs & weber 32/36 carb.

so it's not your "ordinary" 4ac.

the addition of the msd 6al was to have a full combustion of the unburned fuel caused by the hotter cam. we're not looking for horsepower gains but better combustion, smoother idle, throttle respond, and smoothness throughout rpm range. not to mention the added bonus of finally having a rev limiter on the 4ac. thanks to Jonas with his knowledge of fine tuning carburators, we were able to come up with a better combination of carb jets to meet the engine modifications applied.
Or i can round up all by saying "why not" [/b]

[yellowsnow4free]

Hey dr.occa

So since I'm pretty much a noob when it comes to all this stuff, would this convert the stock RWD 4AC distributor (points) + coil (internal) to an electronic distributor and external coil?

Thanks! :D

[dr.occa]

You have a points 4AC distributor!? This shouldn't be the case but then again, I'm prepared to expect the unexpected. What this does is improve spark and burn over stock. You can better complete this by getting a distributor from a 3AC that should use an external coil. Then you would replace the factory external coil with that of say a Blaster Coil 2 and then purchase/make MSD plug wires.

[yellowsnow4free]

You have a points 4AC distributor!? This shouldn't be the case but then again, I'm prepared to expect the unexpected. What this does is improve spark and burn over stock. You can better complete this by getting a distributor from a 3AC that should use an external coil. Then you would replace the factory external coil with that of say a Blaster Coil 2 and then purchase/make MSD plug wires.

My distributor looks just like the one in this write-up. I'm pretty sure it's stock. I guess I assumed it's points instead of electronic

Here's mine AFAIK: http://www.villagetoyotaparts.com/image ... ED357B.jpg

I'll keep an eye out for a 3AC distributor with an external coil; I found a 3AC powered Tercel today and it had an internal one.

[dr.occa]

It'll be out of an 80-82 Tercel.

Here ya go.

[bt20v]

i bet he saw a little bit of power gain with this. I had one on my modified 22re in my old truck eveyone said it wasnt worth it but i tell ya it kept pulling in the higher rpms where the stock ignition fell off. good write up sir

[yellowsnow4free]

It'll be out of an 80-82 Tercel.

Here ya go.

Thanks for the link! :D

So judging by the diagram in my previous post, is mine points or electronic? (idk how to tell )

[suprastarr]

good write up im gona add this to my long list of things to do to my rolla!

[dr.occa]

...

So judging by the diagram in my previous post, is mine points or electronic? (idk how to tell )

Your best bet is to just pull the dist. cap and look inside for a 4 tooth star in the center (your trigger wheel) under the rotor. If you see that then you have an electronic ignition dist. If you don't see that then take a pic and post it so I can be yet again surprised.