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LS coils fail


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VG30DET engine @ 5000+rpm and 15psi boost, big missfire. The coils were all wired up professionally and are direct driven by a MoTec M600 ECU. Of course there is always the possibility that its something other than the coils themselves that is failing but thats unlikely, given the effort that has gone in to tracking down a fault.

 

I don't want any suggestions thanks as to what may be the problem, just a word that LS coils are not bullet proof. Am going CDI now, probably with a M&W system.

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What settings did you have Richard. I am currently using LS coils with an M600 on my L28et. Would like to know if it is going to cause me a problem.

http://forums.hybridz.org/showpost.php?p=953392&postcount=16

 

I don't drive mine as hard as you would drive yours (Mines a weekend warrior not a track car) but I would like to know if it is going to cause me headaches.

 

Also, mind PMing me a ball park on what the cdi unit is setting you back. Are you going with a 4 channel and doing wasted spark or a 8 channel?

Using Motec CDI coils?

 

Good luck

Brad

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It is irresponsible to blame the coils when you have no idea why you have a misfire.

 

Plugs gapped correctly?

Condition of plugs?

Plug wires?

Tuning? Low AFRs?

Coil dwell settings? Timing?

 

Professional installation means nothing. I installed my own and I am pushing 22+ psi without misses.

 

I did have misses earlier, but it was due to plug gap and AFRs too low at that psi.

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Are you going with a 4 channel and doing wasted spark or a 8 channel?

Using Motec CDI coils?

Am going CDI now, probably with a M&W system

Sorry, didn't read the M&W part, my bad.

 

It is irresponsible to blame the coils when you have no idea why you have a misfire.

 

As I understand Richard is using the State Motec Distributor to do his work. (Is that still correct Richard). As I understand the guy does a lot of work with the V8 supercar guys, so he should know what is going on.

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as said many times... manufactured parts have manufacturers defects. the coil's core may be botched. It does not neccessarily mean that the coils suck.

 

I mean, seagate just had a recall on tons of hard-drives that are excellent performers, but have a firmware defect that makes people lose their data.

 

in reality, great hard-drives... in the hands of a consumer, "where the ♥♥♥♥ are my files"

 

the only thing we can do now is work towards finding the weak link in the coils if they are indeed the problem. here's to hoping that the diagnosis goes in the right direction before senseless expenditures occur.

 

I had a low load, low gas misfire on my engine after rebuilding, and I thought I popped a piston. Turns out that the 6th cyl detonated so hard due to my timing being 30 degrees out that it closed the gap. After removing and replacing the wire with 6 others that I had laying around from a Honda Accord, I found it to be the spark plug.

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NO coil is bullet proof!

Professional installation does not mean that there couldn't be something else amiss in the cars electrical system. roll.gif

 

"This part sucks cause it failed on my car and by the way, don't bother with advice"!

Richard, you know that one persons account in one car is not indicative of what everyone else will experience. One vehicle failing a particular coil does not make that line of coils bad and then warrant a "beware of junk coils" warning to the rest of the world. Way too many other LS coils on V-8's and other engines running hundreds of thousands of miles, boosted and otherwise with other brands of aftermarket EFI triggering the coils that are not having this problem.

 

Against not wanting advice,wink.gif I would suspect issue with the cars electrical, (over voltage alternator, bad diode in alternator), improper ign trigger settings/dwell, inadequate voltage to the coils, coil location is subjecting them to too much moister, heat, vibration, etc...

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The problem when you post something like I did is often people don't bother to completely read, understand and consider what is being said, they want to jump in and have a go at you.

 

For example, nowhere did I say LS coils are no good, what I said was in the specific case as set out they are apparently at fault. As we all know, there are plenty of examples where LS coils do the job and more.

 

The request for no advice was simply because the people on it are experts in their field and I've already passed on lots of advice from others who are familiar with LS coil use to them. As an example of the work that has gone into this, the tuner sent a spare coil to MoTec to test for optimum dwell time.

 

Comes the time though when its sensible to move to something else that I have been guaranteed will work, dyno and fault finding time chews up $..

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So Richard, M&W CDI. I've read a little on them since my post. What did Paul Masterson say about M&W units. Do they make the Motec CDI units? or is it just hear say?

 

Also, are you going with wasted spark unit or shelling out for a 6/8 unit and going sequential?

 

Brad

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The problem does not lie in our ability to read but the way in which you made your statement.

 

Thread title "LS Coils Fail"

 

Quote "just a word that LS coils are not bullet proof"

 

Without going into any other discussion, you come out with said thread title and statement. There were more than 1 of us that came to the same conclusion after reading your thread.

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The problem does not lie in our ability to read but the way in which you made your statement.

 

Thread title "LS Coils Fail"

 

Quote "just a word that LS coils are not bullet proof"

 

Without going into any other discussion, you come out with said thread title and statement. There were more than 1 of us that came to the same conclusion after reading your thread.

 

Both those statements are true, in the context of the entire post. So where is the problem with what was said?

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To finish this thread up, there was a point raised concerning the use of a -ve or +ve signal from the CAS. The MoTec agent says either is OK which sounds a bit sus to me but I'll accept it and move on.

 

Yeh M&W 6 channel (Pro 16b) with six Mercury coils. M&W say they make all the MoTec units bar one, which is not to say they are the same design eh.

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I got LS coils on my L28et at the moment. Although I am only running 13psi max boost. I have a couple of extra coils in the glovebox incase I get stuck in the middle of no where. I just haven't driven it enough to know if they are going to be reliable long term. (Shouldn't be any worse mounting then how holden had it)

This was my thread for the mount I made for them

http://forums.hybridz.org/showpost.php?p=953392&postcount=16

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They are going to be reliable in the long term. We do not need anyone running around screaming the sky is falling, especially if they have not truly diagnosed the problem.

 

I am running 22 to 25 psi of boost with my target AFR at 12:1 from 13 psi on. I do not and have not had misfire issues.

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My plugs were gapped down to 30 thou which did move the missfire up the rev range, think ~45 is stock for the VG30DET. No error codes showed up on the ECU at any time.

 

Anyway if the LS coils are not the problem this should show up once the CDI system is fitted, nothing else will be changed because the M600 fires the coils directly in sequence.

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I never had luck with my plugs gapped at 0.03, I was getting misses. I know that others have had to gap them down to 0.025 or even lower in an attempt to cure the misfire issue (not with LS1 coils but just in general here on Hybridz).

 

I would venture a guess that the LS1 coils are not quite hot enough to produce the spark at 15 psi of boost with plugs gapped at 0.03 (don't know your AFR either); I know I was missing and you were too. It may not be an issue of a failure but rather strength.

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