Installing 6A box on Volvo Penta 5.0GL

[craze1cars]

Hello. I have a 6200 MSD box, wanting to install it on my boat powered by a 1999 Volvo Penta 5.0GL. This is nothing more than a Chevy Vortec 5.0 V-8 longblock...just like Mercruisers. But I'm not sure what type of distributor this is, presumably made by Volvo Penta? Pic is attached. It is obviously magnetic pickup, but I was disappointed to find that it does not have any plug inside there to remove that matches your GM compatable wiring harness. And the one-piece ignition module inside the distributor is integrated with the magnetic pickup...so if the module comes out, the pickup comes with it. Obviously that won't work.

Can I just leave the stock ignition module and pickup inside the distributor, and hook it up with the MSD box red & white wires instead, and abandon the magnetic wires on the MSD box?

I was concerned about this approach, thinking that since this is a magnetic pickup distributor, I must use the magnetic green/purple wire output on the MSD box. Is my concern warranted? The stock distributor/module/pickup assembly is working just fine, despite the visible corrosion. So maybe it's OK to just use the white wire on the MSD box to pick up the signal coming from this stock Volvo module?

The 2 wires coming out of the distributor module currently go directly to the coil. The pink/purple looking one is currently hooked up to the + side and is ignition powered 12 volts. So this wire I assume should bypass the coil and instead tap into the thin red wire on the MSD box to power it. Then can I then just hook up the remaining white wire on the MSD box to the black wire that is coming out of the distributor?

I'm not sure if this would work on this setup, and I just want to verify before I do the cutting and splicing. Thank you.

I am aware the 6A is not designed for marine applications. The box will be mounted outside of the engine compartment to eliminate any possibility of stray fuel fumes reaching the box, and protected from any possible water contact.

[msdtech22]

Just by what I see from your pictures, it appears that your distributor is close to what we call a 'Ready-to-Run distributor. The pick-up is a HALL Effect and triggers the module inside of the distributor. The distributor then wires to the coil uing two wires, one to coil POS and the other to coil NEG.

You will use the 'white wire' or points installation when wiring this.

Remove ALL wires fro the POS side of the coil, those wires connect to the small red of the MSD. Return the small orange of the MSD to the coil POS. Remove ALL wires from the NEG side of the coil and attach to the small white wire of the MSD. Return the small black of the MSD to the coil.

When done, the ONLY two wires physically touchig the coil will be the small orange and black from the MSD.

You might need to use an MSD Tach adapter if a tach is originally wired to the coil. The part number for the tach/fuel adapter will most likely be PN 8910. The tach adapter is going to be used to provide a high voltage kick-back signal to the tach in order to trigger it. Usually this is done by the coil, but since that wire has been removed, we need to add or supplement that signal.

[craze1cars]

Thank you! That's pretty much how I thought it would end up, but I feel much better hearing it from a qualified source.

I'll give it a go and will let you know how it works...maybe over the weekend I'll find the time to get it done.

[msdtech22]

Anytime we can help and good luck.

[craze1cars]

Got 'er all hooked up as instructed, and it's running like a top! Only one little issue.

The tach is interesting. It's "working", but reading too high. And not very consistent. When my shop tach says 650 RPM idle, the dash tach says 1,000-ish. Shop tach says 1,400, dash tach says 3,000-ish. At 3,000 on the shop tach the needle on the dash is BURIED. And sometimes is moves around a little...doesn't always stay consistent.

This surprised me. Frankly I was expecting maybe the tach not to work at all...I was not expecting it to just read high. Is this what you would expect to happen? And I fail to understand why my digital shop tach was working fine? I had the red lead clamped to the white wire splice I created (distributor white/MSD white/previous coil negative wire) and negative on engine ground. I'm pretty sure that previous coil negative wire is actually the tach pickup wire...but I haven't traced it all the way to the dash.

The boat tach was working normally before I installed the MSD...though sometimes at idle it would "drift" up high and then come back down again...so maybe the tach isn't all that healthy or I have a separate wiring issue, etc.

Do you think this mean I might need the 8910 you referenced? Or do you think I have a different tach problem? Obviously I would rather not buy the extra MSD part if I'm chasing a bad ground, bad tach, or something unrelated...

If it matters, this is the type of tach I have on the boat:
http://www.iboats.com/Tachometer_7K_...view_id.169274

And this is the shop tach I was using, which still works fine and reads accurately:
http://www.actron.com/product_detail.php?pid=16155

Thanks again!

[msdtech22]

Unfortunately, it is difficult to diagnois whether you have a bad tach or not. If your tach works under a factory condition, it probably works.

Try plugging the tach into the tach output of the ignition and see if the tach reacts correctly. If not, it is looking for a high voltage 'kick-back' from the coil that we have removed. Unfortunately, if this is the case, you will need the PN 8910 tach/fuel adapter.

[craze1cars]

Ok...I'm going to try some rerouting of wires also. Wondering if I'm getting some interference bleeding over to the tach pickup wire from the new multiple spark signals going to the coil, since I have ALL the wires from the MSD box traveling thru the same plastic loom together alongside the main engine wiring harness.

I think first I'll just run a new dedicated tach pickup jumper wire from the dash all the way back to the new junction via a completely different route, and disable the factory tach wire, then see if I get a normal reading at the dash. The fact that my shop tach works fine when wired at this location (independently wired), but the dash tach does not (part of the wire jumble traveling all together to the box), tells me I might not need that extra part at all...but I'll order it if/after I troubleshoot this tach and determine it to be OK.

Will experiment sometime and see what happens, I should be able to figure it out. Thanks again!

[msdtech22]

Not a problem, anytime we can help.