Page 1 of 1

why edis?

Posted: Sat Jul 03, 2010 2:36 pm
by dangerousdave
ok maybe a silly question for a lot of you but i am researching megasquirt still and i wonder why a lot of people use edis controllers still when the ecu runs wasted spark from coil drivers well doesnt it?

im not clued up on it al;l very well so simple talk please! lol, im running a 2l zetec turbo by the way :)

Re: why edis?

Posted: Fri Jul 16, 2010 3:42 am
by arr_kid
Here are a few pros I can think of…

EDIS does the coil switching keeping those higher current circuits away from MS.
Some of the ignition settings can be ignored.
If you have pulled the complete harness you only need to make a few connections.
You don’t need to build the VR circuitry but I suspect that most do anyway.
It has a limp home mode which is probably a bit pointless if your MS dies.

All in all it’s a simple reliable solution that’ll get you up & running quickly

Anyone got anymore?

Re: why edis?

Posted: Sun Jul 18, 2010 12:41 am
by dangerousdave
thanks buddy, i wasnt going to build it myself i was getting it built with 2 coil dfrivers and was going to use duratec coil on plugs in pairs as wasted spark! i just wanted less clutter and crap in the car lol,

so in all your oppinions i should keep the edis4 etc? do i have to keep the ford map sensors if i do? ( currently running a fiesta turbo ofac ecu on my zetec!)


cheers again for your responce mate much appreciated!

Re: why edis?

Posted: Sat Sep 04, 2010 3:25 pm
by gofastant
Because it's there.

Re: why edis?

Posted: Sat Sep 04, 2010 9:51 pm
by Heribert
FORD EDIS is a bulletproof stand alone system available for 4, 6 or 8 cylinders.
It is installed in the engine bay and the components and wiring connector are first class, as is the electrical design.
It is a wasted spark system.
It needs only one engine sensor , a VR pickup that reads a 36-1 toothed wheel that is mounted on the crankshaft.
All VR conditioning is done by the EDIS and it NEVER fails.
There are outputs to the EDIS HT coils, which are for 4cylinders or 6 Cylinders. For a V8 , use 2 off 4 cylinder coils.
It supplies a separate rock steady output pulse for each ignition event , called PIP. This is used by MS as the RPM input.
Forget tweaking potentiometers and keeping track of inverted/non-inverted, dwell time , in dwell, discharge ............
EDIS is your fiend and will do all of that, without even being asked.
From a properly configured MS ( even I manage that) is sent a SAW signal that is used to control the EDIS timing.

No SAW signal means a fixed spark advance of 10 BTDC, provided you have phased the VR pickup correctly.

About the only caveat I know of is to use resistor spark plugs/leads, if not the EDIS internals may diagnose "misfire" and shut down.

Many later FORD ECU-s that moved the ignition stuff into a common ECU-box ( EEC 1-V) has a single ASIC taking care of ignition. It is a
20x20 mm surface mount IC and on it is stamped EDIS4 . So they have certainly ported the excellent old design int a more modern ASIC and keep running EDIS.

Heribert

Re: why edis?

Posted: Sun Sep 05, 2010 8:00 am
by kjones6039
IMHO Heribert is RIGHT ON! EDIS is an extremely robust and reliable system.

In my case I built a totally new engine which was slated to use a new HEI dizzy. During the engine build I decided to try EDIS. I built mounts on top of the valve covers on each bank for the coils (makes a very clean wire routing setup for a V8), fitted a 36-1 wheel to the crank balancer and fabricated a mount for the Ford VR sensor. The wiring was dead simple. Wire to each coil, 2 wires to the sensor, 2 wires to MS, a couple B+ and ground wires and voila!!!

In my case, I cut the top off of the dizzy and machined a cap for it, so it now only runs the oil pump. Gave me lots more room at the back of the engine plus no wires draped all over.

The engine started and ran at 10* advance without any problem. I hooked up the saw signal and had full control of timing. I LOVE it. :yeah!:

I know this is old news to most everyone here. I just wanted to add my 2 cents worth for those who might be considering EDIS on their own installation.

Anyone want to buy a brand new Mallory HEI dizzy??? hahaha

Ken

Re: why edis?

Posted: Mon Oct 11, 2010 5:52 am
by Samuel Powell
Can anybody point me to a wiring diagram of an EDIS system that would be right for a six cylinder? It sounds like a good alternative to an old distributor with a reluctor and pick up. Would the MSD box go away with an EDIS?

Sam

Re: why edis?

Posted: Mon Oct 11, 2010 6:46 am
by kjones6039
Take a look at this.

http://www.megamanual.com/ms2/EDIS.htm

Hope it helps.

Ken

Re: why edis?

Posted: Mon Oct 11, 2010 11:17 am
by Samuel Powell
Yes that was a big help. It is a start for sure. I printed the pages out and will study them until I need more info. Right now, I do not know what a PIP is, but I expect to find out with some reading. I always feel a little silly when I ask a question that is answered in the Manual, but it is so big by now, there is just a ton of material to search through. Thanks again.

Sam

Re: why edis?

Posted: Mon Oct 11, 2010 6:58 pm
by kjones6039
Right now, I do not know what a PIP is
PIP is the "Profile Ignition Pick-up" output at pin 1 on your EDIS6 module which should connect to pin 24 on the DB37 connector.
It amounts to a tach signal to trigger your injectors etc.

SAW is "Spark Angle Word" which is output by MS on pin 36 of the DB37 to pin 2 on the EDIS module to control timing.

The good news (IMHO) is that only 2 wires (PIP & SAW) are required if you use the Ford module with MS.

I am partial to the EDIS system for many of the reasons found in the above posts.

Hope this helps,

Ken

Re: why edis?

Posted: Wed Oct 20, 2010 3:43 am
by Philip Lochner
I'm also a big fan of EDIS (as in ALL my MS'ed) cars run on EDIS.

I like the fact that those high volt spikes are kept away from MS, EDIS is bulletproof and gives me very great confidence that if there are issues, it is most unlikely to be spark related.

The only downside to it is that spark based rev limiting is limited to retarding spark by 25 degrees with the B&G fw (AFAIK). With the Extra fw its still only 12.5degrees (AFAIK)