In need of guidence

[jimbeaux911]

Im trying to bring an 84 back to life. It was stripped to make a track car, and the guy quit.

I have rebuilt a 79 engine with CIS and its time to put it in the car. My question is about the electricals.

Other than the usual engine stuff, dist, coil , Im adding a MSD to replace the missing CDI,
WHAT OTHER ELECTRIC STUFF DO I NEED TO INSTALL TO GET THE ENGINE RUNNING?

Where does the notorious DME go? under the passender seat? I have no wires located inside the cab. or do I not need any?

any and all advice is greatly appreciated! especially if it helps get me up an running.

Thanks!
Jim

[timmy2]

What fuel delivery system is on the '79 engine CIS?
No DME for '79 engine control.
Makes a big difference in what you will need to do.

[Drisump]

Yikes.....a lot. Sorry but even a half baked response would require a lot of additional info that you haven't provided. A DME is part of the Motronic fuel injection system, is that the fuel system on that 79 motor? The normal fuel system in a 79 is not the Motronic but CIS. I don't have an SC so I can't comment on that system. I think you might have to study this site and other sources so you can know what to ask. Good luck on the resurrection!

[jimbeaux911]

ok, so yes the engine has the CIS hooked up, and cleaned up, and ready to go.

[timmy2]

Not knowing how the fuel pump relay is activated in the '84, without a DME, I would have to study the schematics to see what it will take to reconfigure your engine harness to plug into the '84 fuse panel correctly.
May have time to look at it tomorrow.
I've done harness conversions for later motors in earlier cars, only one for early motor in a later car and that was fairly easy as it was a turbo.

You will need the constant hot from the starter to the MSD as well as switched power.
I am curious as to the pressure output of the '84 fuel pump as well in regards to it being high enough for CIS.

[timmy2]

Fuel accumulator installed?

Just read fuel pump spec for 84 is only 850cc/30 sec fuel delivery and 2.5 bar pressure.
You need 1000cc/30 sec and 5.2 bar for your CIS system.
Hopefully the 84 fuel lines are rated for that pressure.

I'll likely have the wiring changes you will need to make tomorrow afternoon or evening.

Definitely no fuel pump relay like '83 down, so it will be interesting.

Though you could run it like the '74/75 with no fuel pump cut out for safety.....

[jimbeaux911]

Well, no DME sounds like a good start! I do have the accumulator installed.

Sounds like I will be buying a new harness from you after all Dennis!
Thanks for the info, I eagerly await to see what you have after looking at the schematics.

Jim

[timmy2]

New harness probably not needed. Just some changes to existing and some possible additions.

[Charles Freeborn]

I believe CIS and Motronic also have different fuel pressures, so a new pump may be needed too.
As for wiring, if you're using a MSD, you'll pull a fresh hot wire from the starter (10 or 12 ga, a fusible link would be smart too) to power it, then what ever is needed to make the tach work.
Interesting back date you're doing. Seldom does one go from a Motronic era induction to CIS...
-C

[jimbeaux911]

Thanks for the comments. so far as doing a 'interesting' backdate. I bought the shell on a whim as it was relatively affordable. Then i found out to buy a motor and a tranny without a core was outrageously expensive, so I got lucky on ebay with a complete engine/tranny out of a wreck. So its unplanned, but Im trying to make the peices fit.

[timmy2]

It will work, just need to make the plan.

[timmy2]

Do you have an open relay base hole on your front trunk fuse panel?

[timmy2]

Send me an email as I have some questions about how you want this to work in regards to a safety fuel shut off or not.

[timmy2]

Simple instructions.
NOT...
Going to take more time to asses. Not having a DME car handy to meter circuits out on doesn't help.
I'm using both the factory and Bentley wiring prints to evaluate.

I'm still trying to find switched power to the rear fuse panel area that is not DME dependent...
You need switched power to your WUR and other devices to work.
So far, only the reverse light switch powered wire seems to be uninterrupted to the rear fuse panel area.
May need to install a relay for the other devices power draw using it!

Once switched power is addressed it is fairly simple to do.:

1. Install MSD unit
2. Install a 78-83 fuel pump.
3. Plug in the 14 pin engine harness connector.
4. Remove the red/green DME fuel pump wire at fuse 3.
5. Install a Jumper from fuse 3 for the fuel pump to fuse 4 at the top where you removed the DME wire with a #12 red wire.
6. Start the car.

WARNING The fuel pump will run all the time with ignition on.
If you want a relay for the fuel pump email me and we can work out the details.

[jimbeaux911]

Dennis all I can say is WOW! and that will take me a while to figure out for sure. LOL

I'll send you my email, and adding a relay is not a problem. You seem to be quite the expert! I appreciate you willingness to help me out. It the end it still might be best to rewire at least the engine compartment. Im not sure what is there now is complete or not. I suspect the 14 pin connector is gone, with the wires hanging lose.

Thanks!
Jim

[mreid]

Dennis has the 14 pin connectors. You are in good hands.

[timmy2]

Good talking to you today Jim.
Pulling out all the old DME wiring and installing a new front to rear harness suitable for your engine is definitely going to be the easiest solution in the long run.