EDIS 6...... no RPM signal

[Mavrick]

I don't know if it has been done before, but I thought mustangs had an EDIS ignition module, and the MSD DIS 4 plus was recomended for a 96 mustang. So I figured it would work no problem. I will contact MSD and see is there is an emulator that needs to be put into the circuit. Thanx for the input as always.

[Mavrick]

So I made some headway but still no still RPM signal to the computer, I am now getting spark. I am getting some signal but it is not a digital square wave like it should be I am getting a 0.2 volt spike. Any ideas?

[Mavrick]

bump

[Matt Cramer]

What does the PIP signal look like if not a square wave? Can you post a picture?

[Mavrick]

here is a picture, it looks like a voltage spike.

http://s987.photobucket.com/albums/ae35 ... G_0138.jpg

[Mavrick]

just for reference this is what the VR sensor output looks like

http://s987.photobucket.com/albums/ae35 ... G_0145.jpg

[Matt Cramer]

here is a picture, it looks like a voltage spike.

http://s987.photobucket.com/albums/ae35 ... G_0138.jpg

If that's just 0.2 volts peak to peak, something is very wrong. What pin of the EDIS module is this from?

[Mavrick]

that is the output of pin 1 from the edis. I have another edis but the one that is in the car right now is brand new from motorcraft. any suggestions are greatly appreciated.

[Matt Cramer]

Does the signal change if the MS is unplugged?

[Mavrick]

Thats a very good question, I never thought to unplug the MS I will do that tomorrow, and check it out. Thanx

[Mavrick]

I finally got a chance to unplug the megasquirt and see if the signal changed at all but saw no change. I even switched the EDIS out with another one and got the same 0.2 of a volt spike. any ideas? On a side note I am not using the ford coil pack, is that really an issue? I am using a coil pack from a mitsubishi 3000gt.

[Mavrick]

bump

[Heribert]

EDIS of various generations are pretty much alike, and most of them ( actually all that I have used)
are diagnosing the actual spark properties by monitoring coil charging current. Shorted or sooted out
plugs , the lack of at least 5 kOhms per spark circuit and probably much more influence the coil charging
and can actually shut down the MS. To get it going again, cycle the power , after which it will spark for a few events,
shut down ....

EDIS 6 is a bit extra interesting, in that the coil charging current is available as a voltage pulse on pin # 4 of the EDIS.

Over one crankshaft revolution there shall be three nice , smooth sawtooth pulses of a few ms each at cranking rpm. If these pulses are
distorted, unequal or the amplitude too low or too high EDIS will shut down. I tried it on the bench with two resistor plugs in each
circuit. Shorting out one plug gave a very distorted pulse for that coil, shorting out both shut the unit down.

So in order to save yourself some agony, try the install with the original EDIS coil pack which has the correct L ( Henry) and R ( Ohm)

If you have wired all OK it will work, if trouble first check your EDIS wiring and then swap the VR sensor leads.

Pin 1 on the module is marked up on the casing, check so you have got this right.

Once you get sparks, connect to MS and try out PIP and SAW, and when that is well you may attempt switching to another coilpack,
but this may screw things up.


Heribert

[Mavrick]

I am actually getting spark, haven't hooked up a timing light to verify if it is in limp home mode or not cuz I am only getting a voltage spike coming from pin 1, a few posts up I posted a picture of what the vr signal looks like, and what the signal looks like coming from pin 1. I wonder if the irregular rotation of my factory starter could be effecting the EDIS in any way. thanks for the response!

[Mavrick]

problem solved!!!! the shielding wire was in some way grounding out signal. thanx for all your responses and help!!!!