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Anyone used an MSD box to fire the ignition without the factory box? K-jet gurus look

badvlvo

Bad for Babies
Joined
Feb 14, 2006
Location
Marina, California
Here's what I want to do-

I have an 80 k-jet car, NA still, an MSD 6AL and appropriate ignition coil.

I would like to keep the k-jet for fuel only and use the factor pick-up coil in the distributor to actuate the MSD box for ignition.

If I eliminate the factory ignition box will the k-jet still deliver fuel properly?

Does the factory ignition box serve as anything other than a signal amplifier? Does it control the timing curve at all?

I am swapping in a turbo engine in the future but that plan has been delayed a bit with the recent happenings at home so I am just using what I have to get the most out of the car.
 
It will work just fine, you have to figure out how to trigger the stock relay for the FP.

The stock relay is triggered by the tach impulse.

Search for dummy coil. You can even use an actual coil for dummy services. A relay works too, maybe. Depends on relay.
 
I can run the pumps off a relay with no problem, relays are easy. I probably could run them off the tach output of the msd box too, if the same signal that goes to the tach will turn them on.

Anyone got a wiring diagram for the ignition they could email me? If I can get the pumps to work off the tach signal coming out of the msd then I am happy. I can wire the factory ign box to only actuate the pumps and that should eliminate any potential k-jet key-on, engine-off flooding issues too.

So the box does nothing to the timing?


I guess I will have to take some pictures and document this one for the NA as well as the k-jet turbo that is replacing the NA.
 
i used msd with kjet diz.

hooked up like dis

msd.jpg
 
Thanks Tom, I already know the MSD wiring, just the Volvo stuff I am missing. If someone has the Volvo diagram I am happy. BTW the MSD diagram is on the back of the MSD ign. box.

What wire sees the tach output signal from the factory ignition box to the fuel pump?
 
Ok, looks like the white/red off the coil '-' should be the rpm trigger for the relay if I am reading the greenbook right. If so, I will just hook that to the "tach out" terminal on the msd and I should be good to go.

If it's this easy I will be happy. If not, oh well, another learning experience.
 
I left the stock coil (-) the way it was to trip the stock relays. BTM worked just like the stock igniter, I just had a boost retard knob on the dash. The car is in my shop right now. I can go take a pic of it if you want but there was no magic or dummy coil needed. :e-shrug:. It is a stock 1983 242 GLT.

Edit: Stock, being the operative word here!
 
The factory relay for the fuel pump is triggered from the white/red wire from coil '-'. This means it's getting tach signal directly from the ignition coil, same as the tach signal.

It looks like I am going to wire the white/red wire from the coil '-' to the tach out on the MSD. This will work according to the wiring diagram. There is no point in setting up a dummy coil when the box already generates the same signal output.

There's no need to add a relay, coil or anything else, just run the white/red off the coil to the MSD tach output.

See p.12 of the 1980 Volvo Wiring Diagrams Green Book.
 
Yep and the blue going into the ballast resistor will turn on the MSD box.

So I add 2 wires, the batt '+' and batt '-' for the MSD, splice in the rest and I am good to go.

I am trying to do this while allowing the ignition to be returned to stock just in case some asshole at a smog station doesn't know how to read an EO number.
 
i have a b21ft 83 hooked up the msd 6btm, no more stock ignition.

i got rid of the FP relay and switched it.

ign on
fuel pumps on
hit the starter
 
its no different than stock.

instead of something triggering the fuel pump relay to turn the fuel pumps on, you are just doing it manually... elimating the FP relay
 
Yep and the blue going into the ballast resistor will turn on the MSD box.

So I add 2 wires, the batt '+' and batt '-' for the MSD, splice in the rest and I am good to go.

I am trying to do this while allowing the ignition to be returned to stock just in case some asshole at a smog station doesn't know how to read an EO number.
Your 6A is too big but my BTM was concealable under the black plastic cover from the stock ignition box. I mounted the BTM on the stock ignition box bracket. You bight be able to hide yours kinda like that. A big red box with cooling fins attracts attention.
 
Yeah, the 6AL is too big to hide, but it's a smog legal add-on ignition. The problem is that it's designed to replace the factory ignition amplifier but the smog asshats think it's a piggyback about half of the time I go to smog a car.
 
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