MSD 6AL on 79 Fiat Spider

[Hvnfn]

Hey guys,

So I installed an MSD 6AL on my 79 Spider... after the install, I cannot get the Tach to work... Have any of you installed this ignition box on your car? Did it require an adapter of some sort?

Before this upgrade, I installed high supression plug wires and new plugs... the tach connection comes off of the 6AL box itself since going from the positive side of the coil with this thing installed would probably blow the tach...

I am not positive that I have the magnetic pick-up wired up right... I wasnt sure which wire was which coming off of the pick-up.

[So Cal Mark]

it does need an adapter for the tach to work. I think the MSD unit is $50-$70 from Summit

[Hvnfn]

I am going to die from a lack of surprise.

Thanks Mark.

I have another question for you, I got this whole MSD fine idea from you...

If the pick-up were wired backwards... what would a symptom be?

[So Cal Mark]

MSD? from me? I advocate using a Duraspark coil.
I don't think it should matter if the pickup is wired backwards, it merely passes a current through a coil in the pickup unit

[Hvnfn]

Ahh.. ok.

Yeah, I tried to find a Duraspark coil locally and would have had to order it. But since the MSD 6AL ignition box was here and on sale, I thought it smart to match MSD box to MSD blaster II coil.

I noticed that in another thread mdburchette<sp?>... I just call her Fiat Goddess... had this same setup, but she locked the advance plate... I cannot say I understand why... why would this benefit a system?

[So Cal Mark]

does the msd unit have electronic spark advance? that's the only reason I could imagine for locking the advance plate

[Hvnfn]

Yes, it does.

[So Cal Mark]

programmable I hope?

[Hvnfn]

I lied... the 6AL does not appear to have a programmable elec spark advance... or I just simply cannot find the documentation on how to program it!

[mdrburchette]

You can run the MSD box with points distributor but we changed mine to electronic. The only reason why we locked the advance plate was because we weren't using any vacuum advance. I did have to run a tach adapter to get my tachometer to work. One other thing I ran into with the MSD was my car wouldn't shut off with the key. A diode in the field wire to the alternator cured that problem.

[Hvnfn]

Ahh... I have the vacuum advance, but I think it is partially blocked, so I am going to replace it... I havent had a problem with the shut-off but had read about the possibility and saw the diode fix in their notes... For some reason though, my car is lacking the power in the upper RPM's even with this box... Mark mentioned changing out the jets on my new DFEV carb... right now they are the stock jets that shipped with it... I just wasnt exactly sure which ones to mess with... the car idles just fine... so, I am imagining that the main jet may need enlarged...

[mdrburchette]

I know nothing about the DFEV carb but have you looked at the plugs? They would reflect if the car was running too lean. Ron has me run my car at high rpms, then shut the engine off and coast to a stop so he can pull the plugs to see if the car is running lean or rich. What gap are you running on the plugs? With the MSD and electronic ignition, I've got mine gapped at .040. That's a big jump from the .024 with the original setup but a larger gap is recommended.
When I dynoed the car after the rebuild and mods to the ignition, the sheet showed my ignition was jumping at higher rpms. It was because Ron forgot to lock the advance plate down. I don't know if not having your vacuum advance working properly will affect the ignition signal at high rpms, but it's another thing worth looking into.

[Hvnfn]

.40 gap is a big jump... wow... I will have to go back and check my gap, cause I know I enlarged it, but I dont think I went that wide.