EDIS RPM dropout after prolonged high rpm

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Joffrey
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EDIS RPM dropout after prolonged high rpm

Post by Joffrey »

I've recently switched my MS2 from running fuel only and triggering off a coil to EDIS. It runs great on the edis but if keep my rpm up say 3500-4000 or more for several minutes at a time, my rpm signal from the EDIS drops out for about 1-4 seconds and then comes back. It never happens at idle. I can rev to 6000 rpm, if it is brief. I found if I accelerate up to 80mph, push the clutch in and idle/coast back down to 60, I can do this over and over without any drop outs. If I go steady 70 it's gonna drop out.
I got the edis module, coilpack and plug wires together on ebay used. The plugwires seem to be resistor type. Should I be using resistor plugs? It feels like something is overheating , shutting off, cooling quick and turning on.
I would like to cut the plugwires shorter to better to fit my installation. Are there custom wire kits that fit EDIS?
Thanks!
trakkies
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Re: EDIS RPM dropout after prolonged high rpm

Post by trakkies »

How much resistance in the plug leads? IIRC, you need a minimum of 10k ohms either via the leads, plugs, or combination of both.

It's quite easy to shorten the plug leads. Lubricate the lead at the plug end, and insert a small pair of snipe nose pliers to grip the wall of the terminal (don't grip the whole thing as you'll crush it). Pull the rubber cover back along the lead. Cut the lead off flush with the terminal, then force one jaw of the snipe nose pliers into the remaining bit of cable in the terminal and open it up slightly, then remove the waste cable end. Cut the cable to length, strip the end, fold over the core (the end you've removed will show how) fit the terminal and re-crimp.
Dave P, London UK.
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
Joffrey
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Re: EDIS RPM dropout after prolonged high rpm

Post by Joffrey »

Thanks, Dave

I checked the longest lead first and found no connectivity. I pulled the lead out of the spark plug boot and found the end was charred off. I had to trim an inch or so off to get a good reading which was 6k. The shortest lead was 5.2k.
I measured one of the plugs ,it was 3.8k I assume the rest are the same as they are a matched set.
So I have 9k between the plugs and wires. If 10k is the minimum, is there another number that's even better? So I just get another set of plugs? Do they come in many resistance ranges?
These leads are so long, they are touching a lot of grounded metal. If there are sparks leaking out before the plug then it might be like having less resistance. My concern in shortening them was not so much how to do it but that the resistance would be even less. Just compensate with higher r plugs?
Thanks for your help!
Joffrey
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Re: EDIS RPM dropout after prolonged high rpm

Post by Joffrey »

It seems strange that the lack of resistance of the leads could cause the rpm signal that the MS2 is getting to drop out. surely the gap that the spark has to jump has lots of resistance. could changing the gap make a difference? I don't even see how the EDIS module would know if the there is a problem with the coilpack'soutput resistance. If it's a noise issue, then having the wire that goes to the grounded capacitor running close to a spark plug lead is a bad idea. The burnt bit on the oe cable could be adding noise tooo perhaps
Joffrey
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Re: EDIS RPM dropout after prolonged high rpm

Post by Joffrey »

I've shortened the spark plug wires. some by as much as 50%. I've removed the burnt bits. You would think reducing the lenght that much would cut the resistance in half. it just took 1k off a 6k wire. min resistance is 8k for wire and plug together. It seems replacement sparkplugs don't list the resistance as far as I can tell. Test run seems to show no more rpm drop outs. I still need to take it on longer trip on the highway to be sure it's fixed.
Joffrey
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Re: EDIS RPM dropout after prolonged high rpm

Post by Joffrey »

Took a long trip on the highway. 200 miles, no rpm drop outs. Seems odd that bad plugwires could cause the edis module to stop sending rpm signal to MS, but that's all I changed.
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