Dual edis system


I can pick up my xjs mid april and am planning some changes to convert to distributorless and a different efi.
Therefor I’m searching for a module named by the designer (philip lochner) “desc” i believe?
I cannot find much information on how to have it custom made or ordered?

I also don’t seem ro be able to send private messagea on this board.

I’d really appreciate of some one could help me get started, thanks in advance.


Hi Jeffery, welcome to the forums.
Personal messages are allowed after you have a few posts/replies under your belt.
I don’t have an XJS or V12 so can’t help in that department but someone will be on in due course to assist.

If you go to your avatar top right of the page you can add other information such as a flag of your choice to indicate where in the world you are situated, mines the New Zealand flag, not to be confused with that big island to the west who likes to think they are better than us but its really just an illusion :innocent:

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Many thanks for the information.
I’m from the Netherlands myself so neighbor rivalry I’m well familiar with.


Jeff, what’s your budget?
You can go for something more modern and fully mappable, but that’s a great journey…

I do not have a certain budget, a hobby is allowed to cost some in my opinion. As long it is worthwhile.
I’m only able to work on the car during leaves anyways.

What did you have in mind? I am not a big fan of megasquirt (issues in the past with a mx5) but am of holley.
Im aware there are more ecu replacements that can do ignition and fuel, but using a sniper and custom manifold would contain everything in 1 unit and make it super easy and neat.
Other suggestions?


Philip was active about 8 hrs ago according to his profile page here as of this posting so I’d imagine a PM will get a response… You can also review some of his old posts and MS links at the same page. He made a lot of progress early on in MegaSquirt’s development and posted quite a bit on the sadly - now defunct MS forums (some links still available by waybackmachine).

Ole Mobeck (mobeck.com) has put together a pre-mapped PnP system for the V12 (not cheap but it replaces a hell of a lot) that you might want to take a look at. Donald Miles, aka XJR5006 who makes XJR replacment bits Facebook Groups can supply an Emerald ECU setup for the V12.

~Paul K

I managed to lay contact with philip and asking about his unit now.

I’ll look into the two systems you’ve mentioned. Not sure if they contain the features I’m after.


There are two other systems that are just as DIY and more open source than MegaSquirt you might want to take a look at if you haven’t already.

Various flavors of Speeduino (which could run EDIS) and RusEFI in it’s various forms, including the uber powerful Proteus version. These are both hardware and firmware systems that are tuned via TunerStudio but are totally independently developed.

~Paul K.

Thank you for the information.

I’ve heard of them and as you say they’re very DIY. While im good with mechanics, I am not at all with programming. This became a problem when we used the ms on a mazda mx5.

The idea of using the sniper is that its fully self contained. As long the sensors are plugged, fuel lines attached and has an intake manifold it should regulate the fuel just fine. On top of that it has proven self learning and can control timing.

Either way I’m 90% sure I am going down this road as long I can buy or have the desc made to duplicate and delay the 12v square wave signal.


You might want to consider fitting a Marelli computer for that since it produces a negative square wave and controls coil dwell. (Not a lot of wiring, and already pre-mapped). You’d have to demux the signal and sequence it. The signal comes from two output channels (per bank). The two tier Marelli distro essentially acts as a mechanical demux AND sequencer (since it’s always at the right cylinder).

~Paul K.

I think there is a small miscommunication here.

The edis module requires a 12v square wave signal at 60 degrees before tdc of cylinder 1. The edis module then sends the signal to each coilpack in wasted spark mode.

Since there are 2 banks and 2 edis systems i need to delay the required square wave signal by 60 degrees for the second bank.

When you do not supply a pip/saw signal to the edis it will go to the default of 10 degrees before tdc.

Normally you would take the trigger signal from the vr sensor on a trigger wheel.
I plan NOT to do this and instead use the ignition output signal of the holley instead. This is the exact same signal, only advanced/delayed compared to the trigger signal in accordance with the ignition map set in the sniper ECU.

In other words, inatead of changing timing with a pip/saw signal as everybody does. I want to delay the trigger signal and run the edis in “dumb” mode on 10 btdc.

This is where i need the desc developed by philip for. But information on it seems rare.