So my car starts bucking again on todays shakedown cruise (and with the PA roads this spring it is REALLY SHAKING!). I pull back home guessing the #3 lead came off again. With the car running I touch the lead pull it off the #3 plug. While I'm doing this the plug wire is shocking the hell out of me!

Like an idiot I stand there looking at it (as it continues to shock the hell out of me) until I drop it and I hear it arcing against something in the engine bay.

I turn off the car and remove the entire lead (I have coil near plug, the lead is only about 6 inches long). Flexing it all over, I can't find ANY breaks in the insulation. these leads are almost brand new, and only have about 200 miles on them. They are very flexible and the insulation seems to be in great shape. The pulse was jumping through the insulation on the wire and arcing against the powdercoated #3 intake runner, causing the bucking. The coil pack is certainly strong!

I moved the wire as far as I could from the intake runner (the pack is bolted right next to the intake runners, so I can only move it so far) and the car ran flawlessly. I went on a 30 minute drive and it was AWESOME.

So... what next. On a wet day its going to be arcing everywhere. I've sat through that ride before. Maybe make new leads with thicker plug wires? Do I need spiral wound?

@mcmark
@spoke

Your plug wire insulation is starting to conduct due to a deteriorating dielectric constant for the insulation material. Replace the wire with a higher quality one that isn't made in China. The heat from the engine is changing the insulation's molecular structure. Try going with pure silicone insulated wires.

Loosely translated, buy new/better plug wires. Are the ones you have the 'resistance' type? Go with copper wire cores.

Can you use copper core wires with microsquirt?

Try running the car in your garage with all the windows blacked out and the lights off. You should be able to see the plug wires arcing.

,yes we used to do that,if yours leads are bad its a great light show ..not,copper cores are great for a stock application but fall short with modern pointless systems.
Real happy with my Clewitt set as they work with my Pertronix II ,Permatune CDI and transformer coil.
Beru solid core seem reliable and reasonable priced if going stock,not sure if there are more options.

@VaccaRabite

What brand wires are you using? I have had good luck with Beru. Even got them at an Oreilly store for 30 bucks.

I’m not using stock wires.

I think I have everything clocked right now so there is no arcing. Car did great on a 20 mile drive this morning before the next deluge.
I’ve only had about 30 miles since I put the head temp gauge back in, and I have only seen head temps above 310 yet. Need more highway miles for sure, but I was pulling a hill in 5th going 90 and it was running nice and cool.

Need to get these little problems fixed so I can really start driving this car.

Zach

Wet day? Are the rain tray, funnels and tubes in place? Engine bay seals?

With the engine running, in a dark space, use a spray bottle set on mist and spray around the eng compartment.

High power coils?
They pack a huge jolt, the EMP goes right through the jacket. I strongly advise not touching or pulling the coil wire off of a CDI. Ever! It's enough it could kill you, BTDT had a engine runaway, yanked the magnacore coil wire off on a MSD, almost knocked me on my ass. my arm was tingly numb for a couple of days.
There's a reason for the warning sticker on 911 CDI's and the grounded plug sheathing.

If it's a Bosch blue coil I doubt it's pushing 25k volts, but some CDI, COP, etc., are 60k+ volts.
Unless for sure the wires are substandard, damaged, arcing, or interfering with a sensor it may be a non issue,

I'd be suspect of the ran tray.

High power coil packs, one per cylinder, with about a 6 inch lead going to the spark plug.

I have a GT grill with no rain tray. When I was using carbs I needed all the cool air I could get to keep the engine in line. Longer drives are needed, but I may be able to go back to a standard engine lid now.

Zach

I may have this figured out. maybe.
I think the heart of it is what Mark H said about the high powered coils overpowering the plug leads.

Monday night the car was bucking. I went into it again with a bunch of ties and tried to clock all the plug wires so they did not touch anything. Today I went for a 40 mile drive and it was perfectly behaved. Not a single buck. So maybe I have this figured out?

Nice afternoon for a drive too.

Zach

Are there specified wires to use with the high power coils? Seems like your wires are not a good fit for the coil.

Why not heed the good advice here and get some new quality wires to solve the problem instead of a band aid approach? You’re temporarily fixing the issue with ties, all you need is one to come loose when you’re too far from home and it becomes a bigger (and much more expensive) hassle then the correct fix the first time.

As far as I know they are the leads that came with the coils (each plug has its own coil).
The kit @McMark built has a coil near plug setup. The plug leads appear to be good quality 7mm silicone leads. The leads are too short for me to see the brand or maker. I suspect they are the leads that came with the coils.

I'm waiting to hear from Mark B. before I order different leads (and If I do they will be custom Mangecore 8mm leads for EFI cars).

Zach

They're 1997-2004 Corvette wires.

Given you are running Megasquirt, I am wondering if you might have an issue with your ignition output settings, to much dwell cranking up the coil output to far perhaps?

I haven't personally run them, but I recall reading conflicting information as to what the dwell setting for those LS coils should be set to and I believe I saw the recommended setting for those change recently. May want to double check.

Just confirmed the MS hardware manual itself was updated as to the recommended dwell to use with LS1 and LS2 coils (assuming you are using these for coil near plug setup)


http://www.msextra.com/doc/pdf/Microsquirt_Hardware-3.3.pdf
"A dwell figure of 3.5ms is advised for LS1 coils.(was 4.5)"

I would check this before spending money on anything.



Fun reading, includes a picture of arcing due to improper dwell...
http://dtec.net.au/Ignition%20Coil%20Dwell%20Calibration.htm

I've sent a message to the magnecore people but I have yet to buy anything. I will look at my tune and see where the dwell is set.

@mcmark can you confirm that these are LS1 or LS2 coils?

Thanks!
Zach

They're LS2 style coils. I think the LS1 vs LS2 is an oversimplification of the variety of LS coils that are available. But there is one critical difference between LS1 coils and all the newer 'LS2' coils -- the wiring is different.

I've tried multiple times to narrow in on proper dwell for these coils, but I always come back to the idea that because of variances in production methods and quality you have to test and set the dwell for each setup. But that's my typical overthinking I suppose.

Realistically, you can lower the dwell a bit and see if it helps the arcing, as well as evaluate if there are any power decrease or smooth-ness decrease. If a lower dwell helps the problem and doesn't have any negative side affects, go ahead and run it.

Dwell recommendation in the MS Manual was lowered for both LS1 and LS2 from 4.5 to 3.5 for some reason. I am guessing those things just really kick. The fact that it was lowered though make me suspect that others may have been having issues with arcing and/or melting coils using the previous recommendation. Just stood out to me as odd that they would have changed the recommendation last time i read through the manual so i figured it worth mentioning. Not sure I would rule out a possible bad component at this point yet though.

I agree on the need for fine tuning and variance in aftermarket coils and for the application. I like running the VW logic level coil packs for the wiring simplicity but seems there is a HUGE variance in quality with those between the aftermarket and VW factory coils. I still chose aftermarket though and take my chances as there is also a HUGE variance in price

Sometimes it feels like we try to do too much to these old TIVs. They are only good for so much and don't like all the extra hop ups. Not the best engine for real performance.

So a bunch of things have been coming to mind lately on this issue.
I was driving the car between rainstorms Saturday, pushing it pretty hard since it was having a "good running" day.

It occured to me that my issues could be the spark plugs. When I'm having issues, its while I'm driving the car around town or with the kids in it, and the engine is running cool to cold (head temps around 250 - temps on this engine rarely get above 330 even climbing hills on the highway in 5th).

I am thinking that the root of the problem may be that I need one range hotter plug, and my plugs are just fouling around town, never getting hot enough to go into self cleaning mode. I'm running NKG BP6ES plugs, and just bought a set of BP5ES plugs (one range hotter for NKG). my thinking is that these may go into self cleaning mode a little easier, and won't load up as much driving around town or taking my son to scouts, etc.

This is plug 4. Keep in mind it only has a few hundred miles on it. It seems to me to be ok to cold. And this was after driving the car pretty hard for an hour, and then taking a slightly more sedate cruise home via wet back roads. Yes, my car is tuned rich.


I know its hard to read plugs with modern fuels.

Next issue. My car's tune has the dwell set to 6.2ms and not the 3.5ms that is currently suggested in the megamanual. right now I only want to change one thing at a time and new plugs will be here Wednesday. Is it safe running that dwell, or am I doing to overheat my LS2 coils. Each plug has its own coil pack.

Finally, the Magnecore custom wires are getting made up. My current (ba-da tsss!) thinking has me on a path that the wires really aren't the issue, but I'll have the nice new ones.

Zach

I am running around 4ms on my coils. 2ms spark duration and 6ms cranking dwell

The new plugs came in today. Hopefully I’ll be able to get them on the car and go for a test ride around town before 1) the next monsoon hits and 2) before I’m camping with the scouts all weekend.

We shall see.

Zach

The BP5ES plugs came in last week.
The Magnecore wires came yesterday.

The wires need to go back. They messed up the order. I'm sure they will make it right.

The plugs I gapped at .045 (which is the going recommendation for LS2 coils.) From what I have been reading, too small a gap causes misfires. So that may have been a contributing issue to my problem, since the old plugs were gapped much tighter then that.

Using the old plug wires, seemed like it idled easily - but with brand new clean plugs that would be expected. maybe tomorrow I'll get a chance to drive it.

Zach

Magnecore is shipping out two new wires today. I knew they would stand by their product.

Zach

not to rain on the party, but I seem to remember some issue with Magnacore wires with the LS coils? I ran the magnacore with my stock coil with no issues, but with the sequential setup I am using the stock LS wires.

Hi Zach,

with Megasquirt I think you should use the NGK BPR6ES or BPR5ES.

B.R.
Frank

Hey @Frank_S
I just installed a set of NKG BP5ES plugs. I'm not sure what the R would signify. Resistor?

Zach

Yes, R is the resistor version. I think the magnicore wires are high resistance also.

Yes. I specified resistor wires for an EFI application.

Zach

Hi Zach,
yes, resistor type. I'm just about to upgrade my engine with Megasquirt and the resistor spark plugs were strongly recomended to me as the standard spark plugs could generate to much noise.

Cheers,
Frank

After the lightning, thunder, hail and a possible tornado I got to drive the car this afternoon.
These are the NKG BP5ES plugs gapped to .045.

First thing I noticed was that the car was idling more evenly. But I just chalked this up to new clean plugs.

Second thing I noticed was that my CHT was reading about 25-50 degrees hotter. You could really notice the one range hotter plugs on the CHT.

The car has a bog just off idle that needs to be tuned out. It’s drivable but you have to be ginger getting going from a stop. It also pops a little on over run. Not loud, and not all the time, but it’s there.

I’m looking for a place in the area that 1) knows aircooled and 2) knows Microsquirt for some dyno tuning. I think I have the plug issue fixed.
I’m thinking either Steve Limbert at Aircooled Racing or Paul at Euro something in Harrisburg. Translog here in York knows my car, but I don’t think he really knows MSII. Or at least did not a few years ago. But I’ll give him a call and see.

Zach

I talked to Steve at Aircooled Racing, and on Tuesday I'm going to be setting up some time for my car to get re-tuned over there.

The replacement 2 wires from Magnecor came in today and went on the car.

Yesterday, I was able to drive the car to the local Friday show. Due to a fatal accident that had I-83 shut down for about 9 hours, it took over an hour to drive the 5 miles to the show on country roads which were totally blocked with cars. My car DID NOT like sitting on hills and just idling, and by the time I got to the show the car was missing pretty bad due to fouled plugs.


But I was able to bring a little class to a huge show full of american iron. And the plugs cleared up on the drive home due to a bit of spirited driving.

Zach