AMC Eagle Den Forum

The Mighty 258 => Engine Electrical Systems. => Topic started by: Zoro on November 18, 2011, 01:11:37 AM

Title: TFI Questions
Post by: Zoro on November 18, 2011, 01:11:37 AM
I know the TFI conversion has been covered a ton on this board but I have a couple of questions that I couldn't find answers to.

Ignition coil:
I've read some write-ups that say not to use the Ford coil and others that say to use the Ford coil. The Ford coil will produce a hotter spark then the Accel coil, correct? If so where do I find the mounting bracket to make everything look nice and clean? Also, I really don't want to hack the wiring harness so what is the cleanest way to connect the Ford style coil into the harness? The connectors are totally different.

ECM Test bypass:
The car runs great as-is and is averaging 23MPG bone stock. Is the ECM Test bypass nessecary for the TFI upgrade?


Thanks!
Title: Re: TFI Questions
Post by: ammachine390 on November 18, 2011, 02:22:29 AM
The best option is to use the Pertronix Flamethrower 40,000 V ignition coil with 3.0 ohms primary resistance. This coil will mount in the original spot, and the amount of modifications to the connections is minimal. Then you bypass the resistor wire in the primary ignition circuit. You do not have to bypass the ECM.

Then you install the larger distributor cap, rotor, and thicker spark plug wires, and gap the plugs to .045" All this requires no modifications.
Title: Re: TFI Questions
Post by: GRONK on November 18, 2011, 09:12:50 AM
I can send you the install instructions if you like.
Title: Re: TFI Questions
Post by: Zoro on November 18, 2011, 09:54:09 AM
Quote from: ammachine390 on November 18, 2011, 02:22:29 AM
The best option is to use the Pertronix Flamethrower 40,000 V ignition coil with 3.0 ohms primary resistance. This coil will mount in the original spot, and the amount of modifications to the connections is minimal. Then you bypass the resistor wire in the primary ignition circuit. You do not have to bypass the ECM.

Then you install the larger distributor cap, rotor, and thicker spark plug wires, and gap the plugs to .045" All this requires no modifications.

Gotcha. For some reason I was thinking all oil can coils were the same.

This is the coil you were referring to, correct?
http://www.summitracing.com/parts/PNX-40511/
Title: Re: TFI Questions
Post by: Zoro on November 18, 2011, 09:55:17 AM
Quote from: GRONK on November 18, 2011, 09:12:50 AM
I can send you the install instructions if you like.

Sure, do they include instructions on how to bypass the resistor wire? Thanks!
Title: Re: TFI Questions
Post by: ammachine390 on November 18, 2011, 10:16:19 AM
That is the correct coil. To bypass the resistor wire, you cut the yellow wire on the starter solenoid, and connect it together with the yellow wire going to the ignition module.  The pertronix coil comes with connectors that go on the coil, so you can use quick disconnects so you can unplug your coil without unscrewing the wires from the posts. For that, I used uninsulated crimp style quick disconnects, then added some solder so it wouldn't fail, then covered it with heat shrink so it's now insulated.
Title: Re: TFI Questions
Post by: Zoro on November 18, 2011, 10:16:40 AM
Quote from: PeterM on November 18, 2011, 10:09:20 AM
It's all right here on the Forum!

http://www.amceaglenest.com/images/Downloads/MIU.pdf

Thanks! I'll try to make a startup video showing the cold start differences between the stock ignition and the TFI.
Title: Re: TFI Questions
Post by: GRONK on November 18, 2011, 01:07:32 PM
I've sold over 1000 TFI kits and installed over 100 my self.  I have never bypassed the resistor.  I'm always game forf learning new and better ways and because of this board I have just changed my coil to a 3ohm coil. 

I've read a few versions of bypassing the resistor, leaving it there, etc....  Personally I have never touched it, but if removing it is better, I'm all ears (eyes)
Title: Re: TFI Questions
Post by: AMCKen on November 19, 2011, 06:13:17 PM
I use the plain old black coil off the Ford I get the adapter/cap/wires from. Looks stock and no cutting or splicing needed.
Title: Re: TFI Questions
Post by: ammachine390 on November 19, 2011, 06:56:45 PM
Quote from: AMCKen on November 19, 2011, 06:13:17 PM
I use the plain old black coil off the Ford I get the adapter/cap/wires from. Looks stock and no cutting or splicing needed.

If its the cylinder coil, isn't that the same one that Eagles use as stock?
Title: Re: TFI Questions
Post by: AMCKen on November 22, 2011, 01:35:02 AM
The ones I compared had more volts. With the original AMC coil the spark would jump about .5" and with the Ford coil about .625".