TFI to EDIS Thought Experiment

[PetroleumJunkie412]

Maybe easy on the 2.9 jokes on this one... Haven't been able to find any good info on a Cologne TFI to EDIS conversion out there, and would like to have a decent record of this if it works out. ??



So I've been kicking around switching from the TFI system to the later EDIS with crank and cam position sensor.

Why?

- Aftermarket quality on TFI modules is garbage. I'm on my last Motorcraft module, and don't want to risk being down and out. Granted, haven't blown any since I relocated it, but they're time bombs.

- Distributors are only so accurate. My standalone ECM can regulate spark to 1/10 degree with perfect accuracy. I don't know if the TFI system retains that same level of accuracy. Seems that EDIS does, but I genuinely don't know enough.

- From my understanding, EDIS systems are less prone to heat and water issues. TFI modules don't have a great reputation with either.

- Distributors are prone to spark loss

- The 2.9 / 4.0 caps and rotors left on the market aren't exactly of the highest quality. So, GIGO (garbage in, garbage out) is probably kicking in.

- Cologne distributors are a pain in the a** to get to, even with the low profile plenum I have. This last round of hooking up the oil pump and getting the distributor to mesh properly really burned my a**.

- SCIENCE!




From what I can tell, it looks like the two most important parts, the oil pump drive and cam sensor will bolt in, as well as the crank position sensor and pickup. Correct me if I'm wrong here. This is the part I'm really unsure of.

So! EDIS experts:

- Does the EDIS system carry any inherent advantages over TFI beyond terms of reliability? Is the spark that it produces stronger/more accurate?

- What's the total list of parts that I will need, minus a Ford ECM? I'm seeing a optical wheel and sensor, some sort of sensor and drive at the distributor hole, and a six coil pack. There have to be parts I'm not thinking of and will need.

- Is it worth looking into EDIS, or going straight to coil on plug and seeing if I can find one that will adapt out of a newer V6, even if it's not a Ford system?

 

[Uncle Gump]

I will give you my thoughts...

Just look at the amount of data you get... EDIS vs. TFI.

100 data points vs. 3 data point per crank revolution.

If you can make it work... it would be totally worth doing.

End my thought...

 

[Dirtman]

Aren't the 4.0 and 2.9 close enough that you could just use or at least modify parts from a 4.0 EDIS?

 

[Snoranger]

Distributors are sloppy and archaic. Throw it in the trash and step up to EDIS. A perfect condition mechanical distributor will never match the precision of electronics. Moving parts need tolerances to move... tolerances = inaccuracies.

 

[rusty ol ranger]

Aren't the 4.0 and 2.9 close enough that you could just use or at least modify parts from a 4.0 EDIS?

I was wondering that myself.

A 4.0 ECM should run a 2.9 shouldnt it? Then it would just be a matter of driving the oil pump and mounting stuff.

 

[Dirtman]

I'd imagine the 4.0 ecu would need a different tune in order to compensate for the larger displacement without constantly causing a CEL.

 

[PetroleumJunkie412]

So this is confirming my suspicions. Excellent.

Rusty makes a good point. Always wondered that.

So as far as a list of parts, and whether or not to use a simple drive gear or one with a cam position sensor integrated into it, anyone know offhand what my options are? Pros and cons of each?

 

[rusty ol ranger]

I'd imagine the 4.0 ecu would need a different tune in order to compensate for the larger displacement without constantly causing a CEL.

Im not sure. Cause the O2 should compensate enough. As in, the O2 will see its rich and back the fuel off to keep the 14:7:1 a/F ratio.


I think.

They are both batch fire map systems. Only difference is one has EDIS the other dont. As long as you use parts from an earlier 4.0 id think itd be fine.

 

[PetroleumJunkie412]

I'd imagine the 4.0 ecu would need a different tune in order to compensate for the larger displacement without constantly causing a CEL.

Not sure on that one. It's possible that it may just run it a bit rich if everyrhing else matches the 4.0 wiring. Nor sure at all.

 

[Dirtman]

Im not sure. Cause the O2 should compensate enough. As in, the O2 will see its rich and back the fuel off to keep the 14:7:1 a/F ratio.

Yes it would more than likely be able to adjust the injector pulse width and run fine, but it would cause the fuel trims to peg out and the computer would see this as being a problem and in all likelyhood throw codes for running to rich. Im not saying it wont work, just that it would cause a CEL unless you tune the computer so it knows it's now working with 1.1 less liters of displacement.

 

[rusty ol ranger]

Yes it would more than likely be able to adjust the injector pulse width and run fine, but it would cause the fuel trims to peg out and the computer would see this as being a problem and in all likelyhood throw codes for running to rich. Im not saying it wont work, just that it would cause a CEL unless you tune the computer so it knows it's now working with 1.1 less liters of displacement.

Id have to look it up, but im pretty sure ive read of guys running 5.0HOs with 351 ECMs. Would be about the same deal.

 

[Snoranger]

The early 4.0 without the cam sync was batch fire. The later 4.0 with the cam sync was sequential.
Both were wasted spark and fire opposing cylinders at the same time based off the crank signal. That would mean with your aftermarket ecm you could use either setup. I'd suggest you switch to dual platinum plugs because 1 spark plug fires the opposite direction then the opposite cylinder.
You would need the 36-1 crank wheel if you were to go with a stock setup... I'm not sure what you can and can't do with your aftermarket ecm.

 

[Elutheros]

I swapped out my distributor for EDIS a year ago and see no reason to turn back. In order to do it with the 5.0 I changed to a MegaSquirt Plug and play ECU. It seemed like the simplest way to make everything work for me. The tuning was a steep learning curve, but overall worth it. There is lots of information out there on how to do it--the hardest part for you may be the toothed wheel for the crank sensor.
http://www.megamanual.com/ms2/EDIS.htm

 

[PetroleumJunkie412]

I swapped out my distributor for EDIS a year ago and see no reason to turn back. In order to do it with the 5.0 I changed to a MegaSquirt Plug and play ECU. It seemed like the simplest way to make everything work for me. The tuning was a steep learning curve, but overall worth it. There is lots of information out there on how to do it--the hardest part for you may be the toothed wheel for the crank sensor.
http://www.megamanual.com/ms2/EDIS.htm

I'm running the DIYPNP 1.5 on mine. Basically a microsquirt with a bunch of auxiliary ports and some other interesting features. I've read that one a few times. It's what's inspiring the idea of a conversion.

If you think tuning a 5.0 is bad, try tuning a 2.9 from scratch with no maps or setups available, and this is your first foray into tuning ? if it weren't for @deathbypsi, I couldn't have done it

The early 4.0 without the cam sync was batch fire. The later 4.0 with the cam sync was sequential.
Both were wasted spark and fire opposing cylinders at the same time based off the crank signal. That would mean with your aftermarket ecm you could use either setup. I'd suggest you switch to dual platinum plugs because 1 spark plug fires the opposite direction then the opposite cylinder.
You would need the 36-1 crank wheel if you were to go with a stock setup... I'm not sure what you can and can't do with your aftermarket ecm.

Basically any imaginable ignition system is on the table. I was looking into EDIS due to common junkyard parts, but am completely open to suggestions if there are better ones out there from other makes and models. Also I can hybridize multiple systems if need be. Know of one better than EDIS?

 

[fastpakr]

Id have to look it up, but im pretty sure ive read of guys running 5.0HOs with 351 ECMs. Would be about the same deal.

Sort of. Principles are similar but the 5.0->5.8 swap is a lot closer in displacement (16% jump compared to 38% on the 2.9->4.0). You're a lot more likely to go outside of what the ECM is able to compensate for.