TFI upgrade attempt

Need some help please.

I found LOTS of good information online about the TFI upgrade...I gathered my parts list and went to the store tonight. Had to order the adapter, but they had an MSD cap & rotor kit that I bought. Got home, removed my cap and rotor and went to see if the two rotors were similar so they would push onto the distributor...of course they are not...but why not?

My questions...is my distributor the correct type to upgrade? If so, is the MSD rotor button the right part? Or is there some other explanation as to why the two buttons are so different that the MSD clearly won't press onto the distributor.

 

Yeah I did the same thing when I fist did my upgrade. There are two types for Ford's, the one you bought MSD P/N 8482, and the correct one MSD P/N 8450. The 8450 is for Ford duraspark, or you can order MSD P/N 8414 from summit racing, it comes with cap/rotor/and adapter. Hope this helps.

 

That is the part number I bought. Good thing I'm in no hurry for this. I'll return it and get the right one tomorrow.

One last thing...this is the right distributor candidate for a TFI upgrade...yes?

Thanks!

 

Looks like the correct distributor. When I did my upgrade, I started with a new (remanufactured) distributor.

Went down to the local NAPA and asked for a distributor from a '78 CJ5 with 304 V8. (NAPA part # is: NRD484891).

I also picked up the cap adaptor from an '86 Ford F250 with 351 V8
(NAPA part #: MPEFA146SB)

Rotor
(NAPA part #: MPEFA144SB)

Cap.
(NAPA part #: MPEFA134SB)

TFI Coil
(NAPA part #: MPEIC24SB)

and Coil connector.
(NAPA part #: ECHICC1)

I pulled a mounting bracket for the TFI coil from a mid-80's Ford LTD, although you can find one of these in almost any mid-80's through mid-90's Ford. Some are just located in easier to reach places than others. I also pulled the connectors that match the ignition control module from this vehicle and used them to create a wiring harness so as not to require cutting the connectors off of the new module I purchased (this voids the warranty).

If anyone is interested, I have a correct wiring diagram for this mod that I had to make myself, as there are numerous ones online that are either unclear, incorrect, or both. The mistakes I've noticed are between the starter solenoid, coil, and ballast resistor. YOU DO NEED THE BALLAST RESISTOR WITH THE FORD IGNITION CONTROL MODULE. It may work for a long while without it, but eventually will fail. TRUST ME.

I'll take some pics when I've got daylight again of my completed setup. It's been running for over a year now with no problems.

 

So my understanding that the resistor is needed only when you don't upgrade the ignition module, with something like a MSD6 that has a full 12V throughput, is correct. I'm planning on upgrading the module as well to take full impact of the TFI upgrade so I shouldn't need the resistor.

I could use that diagram you speak of. I'll PM you with my home email. Thanks.

 

That's correct - No ballast resistor required with the MSD6 or similar by other manufacturers. I actually created two diagrams, one with motorcraft type module, and one with MSD type module. The wiring harness I built can be used either way, that way if my MSD module goes bad, I can quickly swap in the motorcraft type that I keep as a backup and is readily available at any FLAPS.

I'll send you the diagrams this weekend, and post them here as well along with some pictures. Hopefully it will save you some headaches.

 

Thanks.

You know, when you think about the redundancies that many of us think about, it's almost a good argument to get a Bantam trailer to haul all these extra parts around..."just in case"

 

Indeed. I figure if it has broken twice on its own under 'normal' use, then it's a candidate for a backup. So far, all that's in my box is an ignition module, and a clutch pedal-to-bellcrank linkage.

 

Okay, here are some pics of my modified TFI ignition system.

From left to right: starter solenoid, ignition module, TFI coil, ballast resistor

 

That looks very neat. Do you have a wiring diagram as well?

 

Here it is:

 

Thanks. Apparently you're an artist too...this is one of the better electrical drawings I've seen.

 

Thanks. I'm also an electrican and electrical engineer. I started with a few other descriptions and diagrams from other internet posts, and after working out the bugs, this diagram is correct. Actually, this could be used for any vehicle with an electronic distributor.

Believe it or not, even the manual that came with my replacement 'painless' wiring harness has a few errors in it that made for extra confusion. All of the great technology we have these days can't make up for old-fashioned quality control.

 

LBOGRS, A big thanks to you for this. I think your wiring diagram and write up needs to be in the tech section. I have looked for a simple diagram as you did for almost a year now. They are all inconsistant or confusing. I have part numbers on the diagram. I really like the way you wired it up in the picts. Very clean.

Can you please post the wiring diagram using an MSD box?

Thanks........

 

Thanks aallison. Putting part #'s on the diagram is a good idea. I don't think I have rights to post in the tech section, but I'll look into it. As for the MSD box diagram, I'll try to get it up this weekend or sooner. One of these days I'll draw them up in CAD.

 

I can link to a diagram using the MSD box, from TeamRush/JeepHammer/JunkyardGenius.



Form this thread: http://www.jeepforum.com/forum/f8/ignition-module-msd-6-a-709187/

There are a lot of threads on JeepForum.com about this topic.

 

Tim, I have that diagram and that is a good example of what I'm talking about as far as being inconsistent. From the first diagram, the Starter solenoid is wired one way. ON the diagram you posted, it's wired completely differently. With the different iginition system, is the solenoid wired differently?

The small red wire on the diagram you linked goes to the "former duraspark module or the old coil redwire terminal". But I don't have either. I will be making the wiring harness basically from scratch. So where does it go? I assume it is a constant power?

But the diagram from Team Rush is by far the best I have found. I tired to figure it all out a few weeks ago here. I never 100% understood where the wires go. And it being the ignition system I figure I can very quickly fry something. And once the smoke gets out, it's real hard to get it back in. But it's very, very good and I appreciate all the work that was done to put that diagram togetehr by Team Rush.

I'll be cruious to see the side by side from LBOGRS to the Team Rush one.

And I hate to be ignorant but so far I have not gotten clarification so I can understand on this and other a couple other issues.........

 

Well, the diagram from LBOGRS is quite good, but it's for the Duraspark module. The diagram from teamRush is for a MSD capacitive discharge module. The large red wire and large black wires to the MSD module don't have a comparable connection on the Ford module. These are heavy guage dedicated hot and ground wires, exclusively for the (power hungry?) MSD module.

Apparently the MSD module does not need the black wire from the Ford (Duraspark) distributor. I exect the Ford module grounds the black wire, so that the variable reluctor (VR) signal is ground referenced. The MSD uses the VR floating, so no ground connection.

The small red wire is the same for MSD or for Ford. It connects to the hot side of the ignition switch. Normally the Jeep would have a red wire going to the coil that energizes the coil. You can see that in the Ford drawing. In the MSD setup, the coil is energized by the module, using the orange wire.

Both these setups turn the coil on and off (like points) through the module. On the Ford setup, this is a green wire, and on the MSD setup, it's a black wire. No difference here except in the color of the wire.

There's a white wire on the MSD module that isn't used, except as an anti-theft switch as explained by JeepHammer. The Ford module has a white wire that connects to the S (start) terminal of the solenoid. I presume this activates a feature of the Ford module, which retards the spark for easier starting when the engine is hot. No comparable connection on the MSD.

The I (ignition) terminal on the solenoid bypasses the ballast resistor and sends 12V to the coil when starting, to give a little extra spark voltage at startup. I expect you don't need this feature with the MSD ignition.

From the ignition switch, the blue wire cranks the starter and the red wire is the "key on" power, going to the ballast resistor and to power the Ford module.

That's the gist of it. Have I missed anything? You still need to connect the S wire to the ignition switch, thought the I terminal isn't needed in the MSD setup. But that just turns the starter - it doesn't affect the ignition.

 

The 'I' terminal is a full voltage feed for your ignition coil when you are cranking the vehicle. Ignitions with points used to use it to give full voltage to the coil when cranking to help the vehicle start and then when the key was turned to run instead of start the voltage would run through the resister. The Duraspark ignition has an internal switch for spark tables between run and start and uses it also. The MSD ignition does not do any of that and gets all of its operating power directly from the battery so the I terminal will be unused when you use an MSD ignition. That's why they are both wired differently at the relay.

The small red wire goes to a switched 12 volt source like the ignition switch. It is what actually turns the unit on and off.

 

Tim, in the wiring diagram you posted there is an explanation at the bottom in red about how some jeeps will experience engine 'Run On'; where is the 'Excite' or #1 terminal wire located in order to install the diode?