What ignition system for an EFI?

[Mach1 Driver 560]

A points ignition for an EFI causes problems because it is very noisy and the digital circuitry in the EFI has trouble discerning if the signal is hi or low. The EFI manufacturers prefer a clean square wave to trigger them.

I see no need to spend big bucks on a fancy new distributor. I’ll have my old distributor recurved and have it do the timing. The old technology still works very well with a little tune-up, and should make the EFI setup easier.

For a points replacement I intend to try a Pertronix. The “I” has the problem of destroying itself if the key is left on; the “II” resolved this issue, and the “III” has multiple sparks and a rev limiter. The problem with the “III” is that the multiple sparks confuse the EFI. I really want a rev limiter so what I want to try is a Pertronix II with a Pertronix 600 Digital Rev Limiter ($145.47). They claim that the limiter has an output that is a clean square wave for the EFI and tach. That should solve the issue with multiple sparks from the "III" but I'll still have the benefit a the rev limiter and a clean output. If anyone has tried this I would sure appreciate a shout-out of the results, or perhaps you have a better solution. I’ve already stated that I don’t want to plop-in a new distributor. My cam manufacturer has cautioned that almost all new distributor gears come from China and are junk. For this reason and to keep the “original look” I want to keep the old distributor.

[Mike65 475]

I am going to be using the Pertronix II Flamethrower distributor, Flamethrower coil, & the Digital HP ignition box. With that ignition box you have programming functions, cylinder selection, trigger type, & fatal rev limiter to prevent catastrophic engine failure.

[Mach1 Driver 560]

5 hours ago, Mike65 said:

I am going to be using the Pertronix II Flamethrower distributor, Flamethrower coil, & the Digital HP ignition box. With that ignition box you have programming functions, cylinder selection, trigger type, & fatal rev limiter to prevent catastrophic engine failure.

That sounds like that will work for you. The Digital HP box has high output and somewhat like an MSD-6. Anyone with EFI will be at the mercy of their electronic packages. I want to minimize that as much as possible, but I don't know if it really matters- if any one of them goes out we will be FORD (found on road dead). I've been trying to think of the CHEVY acronym but it escapes me at the moment.

[69volunteer 84]

keep us posted on your EFI setup. What version did you end up using? 

[Mach1 Driver 560]

17 hours ago, 69volunteer said:

keep us posted on your EFI setup. What version did you end up using? 

I intend to use a Sniper. I'm in the planning stage. So far I find that everyone has used an aftermarket distributor. That's understandable, since a clean square wave is needed to trigger the EFI. But with a good trigger from a rev limiter the old dizzy should work quite well.

[det0326 179]

FiTech has rev limiter and I thought the Sniper did too. The old durospark ford distributor will work with FiTch too and assume will work with Sniper

also.

[Mach1 Driver 560]

2 hours ago, det0326 said:

FiTech has rev limiter and I thought the Sniper did too. The old durospark ford distributor will work with FiTch too and assume will work with Sniper

also.

yes they do, but only in timing control, which I'm not going to use

[det0326 179]

21 hours ago, Mach1 Driver said:

yes they do, but only in timing control, which I'm not going to use

It is my understanding that the FiTech will cut spark and fuel about 200 rpm's over set point  using timing control or not. Maybe the Sniper doesn't  I'm not sure about it.

[Vicfreg 771]

I have a Pertronix III plug and play distributor wired to the Pertronix digital HP box.  I am running FiTech EFI.   I needed to go to the DHP box so I could get a clean square wave tach signal to the EFI system.  Have not yet run the engine in this configuration, will be doing that in the next month or 2.

I am not using the DHP box for anything else, nor am I using the FiTech to do any other functions than fuel injection

I have wiring block diagrams that I developed if you need them.