Help...EDIS-8 Will not rev over 6000 rpm???

mayngo · Post by **mayngo** » Sat Jun 05, 2010 5:53 am

Ok, got my megajolt running pretty good on a 1968 Camaro with a 383 V8. Love the idle, how smooth it is and how rock solid it revs through the RPM range, but it starts to "cough" at 6000 rpm, actually the data log says about 5970 RPM. Anyone have any ideas on how I can get about 500 more rpm out of it? I think I read some where that different EDIS modules have different RPM capabilities with the highest rpm being about 6600 rpm with an 8 cylinder. Will a module out of a ford Cobra or some other higher performance car help me here?

I'm running brand new accel coils.
New MSD wires.
New resistor plugs.
14 gauge wire to MJ and coils.
VR sensor seems to be no more than about 1mm away from trigger wheel.
Trigger wheel is 8 1/4" in diameter. 1/8" thick (from DIY-Auto tune)
I have the rev limiter set to 7000 rpm.

Anyone have any ideas that I can try out?

Thanks

cng1 · Post by **cng1** » Sat Jun 05, 2010 7:57 am

What part code have you got on your EDIS-8?

6600rpm is the limit we see on some modules, 7000rpm on others but we have seen an isolated case of around 6000rpm in the past.

One thing to check is that your module is well heat-sinked as on overly hot module could exhibit similar symptoms.

mayngo · Post by **mayngo** » Sat Jun 05, 2010 5:03 pm

I'll look at my part code later and post it.

So different modules DO give a higher rpm potential??

Which cars have the best modules for performance? Lincoln Mark VIII, Mustang?

cng1 · Post by **cng1** » Sat Jun 05, 2010 5:09 pm

Models vary yes. I really couldn't say which vehicles are "best" though. Over here in the UK you can find pretty much any module on any vehicle, it's not quite random but it's not a million miles off.

mayngo · Post by **mayngo** » Sat Jun 05, 2010 5:23 pm

I may go to junkyard today. Is there a "good" module part number that I should be looking for?

thanks...

mayngo · Post by **mayngo** » Thu Jun 17, 2010 11:42 am

Changed module to one from a Lincoln Mark VIII, it still will not RPM any higher than 6000 rpm.

What else can I check???

cng1 · Post by **cng1** » Thu Jun 17, 2010 11:48 am

Check that you've not set a rev limit in the configuration and verify that your trigger wheel is concentric. Aim for a runout of 0.5mm or less.

Spockie-Tech · Post by **Spockie-Tech** » Thu Jun 17, 2010 1:40 pm

To get a clearer picture of the problem area, it would help to get an Oscilloscope or Auto "Tune-Scope" (if you can find a shop with one these days) with an experienced operator to have a look at the coil drive waveforms and the signal from the VR sensor.

That should help narrow down if its an input (VR) or Module problem.

Also, can you try different coil packs ? The coils might be falling off in voltage.. (a scope will help you tell this too)
some aftermarket coils are "high performance" only in that they are painted a different color.. ;-\

mayngo · Post by **mayngo** » Thu Jun 17, 2010 7:48 pm

Thank you for replies. I don't have or know anyone with an Oscilliscope, although maybe I can ask around. The rev limiter is set to 7000rpm and the coils are brand new (and yellow), not to say that they cannot be bad.
The one thing that I could try, is to get VR sensor a little bit closer to the trigger wheel. I'm about 1mm away from wheel, but sensor is not set up at exactly 90* to the trigger wheel, the bottom part of sensor is a little bit closer than the top of the sensor. Could that be a problem? I will see if I can get the sensor a little more "true". I will try and post a pic of my trigger wheel aligned with my VR sensor.

By the way, I'm using shielded microphone wire for VR sensor, could that have anything to do with it?

Other than high RPM problem, the timing seems rock solid.

DannyP · Post by **DannyP** » Fri Jun 18, 2010 12:32 am

How secure is your VR bracket? Sometimes there can be a vibration-induced harmonic of the bracket that can cause a glitch. Possibly an RF frequency can be generated around 6000 on your engine that EDIS is sensitive to.

I had an interference/glitch when my turn signal switch was engaged, the interference was from a trailer light converter into the EDIS. Removed trailer converter and rewired turn signals with a new flasher and relays, problem solved. NO MORE glitches.

On the microphone cable, do you only have one end grounded? If so, great, if both ends are grounded, REMOVE the ground at the sensor end. Leave it grounded at the EDIS end though.Try moving things around, one item at a time, so when you find the problem you really know it"s the problem.