Ignition Module Compatability

Hi All,

I notice that motorcraft still offers an ignition module, but that it's not crosslisted for a 4 cylinder.  Certain aftermarket items are crosslisted.  In my mind I am thinking "this thing has to work" but has anybody tried that?  

For instance, the one carried by the Mustang resto vendors is Ford's part number is  DU2Z12A297A and they generally show it fitting everything under the sun up to 1987 including thunderbirds.  Cylinder count clearly has no impact on this.  I ordered one for my Mark VII but I am thinking I might try it in the TC just to see how it does.  I doubt I would learn anything from that.

They also still have  5U2Z12A297B which fits a lot of cars through 1990 and trucks to 1997.  Cylinder count clearly has no impact on this.

They also show 5U2Z12A297D which covers the mid-90s cars up until they quit using distributors, I guess.

Just making conversation mostly.

I have no idea!
hopefully either someone will have further insight on this or ready to be a guinea pig.

I do know that TFI modules came in at least two versions. One version had what Ford called CCD which stood for Computer Controlled Dwell and the other version had fixed dwell time. Not sure in the two versions are interchangeable or not. My guess is not.

Well, I might do some experimenting, but I don't have a scope.

Well, I might do some experimenting, but I don't have a scope.

I'd like to see some scope traces from various TFI vendors. I just installed a remote TFI heat sink on my 85 XR. In doing so I threw a genuine Motorcraft TFI in the heat sink that had been laying around as a spare. I had been running what I think was a Standard Motor Parts generic TFI in the stock location, and was having no problems with it. The Motorcraft TFI really punches starting right around 4k rpm, whereas the Standard TFI just continued through that rev range, pulling smoothly. I sort of remember this behavior MANY years ago with this same XR. Is this a Motorcraft thing? The only variable with this XR is I just upgraded to an LA2. Anyone else experienced this difference between various TFI's?

I'm curious about this because I'm looking to replace my TFI. A word of warning on the current production Ford TFIs, they're garbage. We do A LOT of SBF stuff and the current Ford TFIs are the same foreign made stuff that you get from a local parts supplier. The general consensus is that NOS FORD, not Motorcraft, modules are the only known good units and the rest are hit and miss. I would love to find an aftermarket solution that actually works but to this point I'm not aware of one.

I do not know about how interchangeable they are but many of the aftermarket performance suppliers list only one TFI for everything which lends me to believe that they are fairly interchangeable. I've got a couple laying around that I want to play with but I haven't had a chance yet.