Help with first wasted spark project

[ChevelleFan]

As mentioned in my PM, I too run 4 squirts/alternating on my V8.

-Dave

[Tonyorlo]

I only have 1 set of injectors. I initially had it on 2 squirts simultaneous. I tried 2 squirts alternating, but it acted the same. 1 squirt simeltaneous seemed to reduce the backfiring. I backed AE down to 0 just to minimize factors that add fuel. I figure I can slowly add fuel to as I go.

[rickb794]

If you have 1 injector per cylinder you will not use staging. Staging applies to multiple injectors per cylinder.

[Tonyorlo]

Ok that makes sense to me.

I've played with the VE map for days, as well as other things. I've slowly leaned out the area it backfires in when the truck is in park. I get to the point of loosing power and get backfire through the intake. I've driven around data logging and running VE analyzer and watching the AFR it's pretty close to my table. It does go rich during the backfire, sometimes to 10.5-13.5 but I don't feel like that is the cause.

My next step I guess is to replace components. I am using used d585 coils, could a bad coil cause a backfire? Is there a way to test coils? I'm honestly considering installing an HEI just to simplify things.i hate to give up but I want to drive my truck. I may have gotten in over my head trying to go to a crank trigger ignition.

[rickb794]

I don't know if it applies to the coils you are using, but some logic coils will randomly fire if over-dwelled.

Have you researched the correct dwell for the coils you are using?

[Tonyorlo]

I have, and I have stayed on the conservative side. I am currently running 3.5ms. I have not made any changes to the dwell battery correction table though.

One thing is that I notice, when I fire the truck up I can to make it backfire untill it has ran for about 1 minute. I am getting them from both side. I have a side exit exhaust so it's easy to hear the difference.

[ChevelleFan]

Tony, I happened across this thread while looking for something else: http://www.msextra.com/forums/viewtopic ... 01&t=58437

Might be worth a quick read and see if it applies to you. There was a a post about resistor plugs + resistor wires being a potential problem.

-Dave

[Tonyorlo]

Dave thanks for that. It could possibly be my problem. I am still running the recommended plugs fpr my engine. I did not change the type when I went to coil fired. That could be a problem. I pieced the plug wires together using this,

Wire
https://m.summitracing.com/parts/TAY-35671

Coil boot
https://m.summitracing.com/parts/TAY-46069

Plug boot
https://m.summitracing.com/parts/TAY-46001

Plugs(per blue print engines recommendation)
https://m.summitracing.com/parts/cpn-13

With my coils mounted remotely that puts me in a tough spot for wire.

[rickb794]

I would use plug wire like this

https://m.summitracing.com/parts/tay-35092

I cannot say this is conclusively your problem, but if you google "spiral wound plug wire problems" you will see why I don't use it.

[Tonyorlo]

After googling it, I did come across multiple articles discussing spiral core wires So I may just give it a try. I lowered the Dwell down to 2.5ms but the problem still occured. When looking up wires for 4th gen Camaros on summit racing's site, and they are all spiral core.

[Tonyorlo]

Well I may have found the problem, Looking at my data log my RPMs go to - 3030 rpm. What causes that?

EDIT: Thats the RPM DOT, but another thing I notice is that the dwell goes up to above 9, I had it set at 2.5ms on that log.

[hybrid]

On my setup, I just bought a set of LS1 coil boots (Taylor brand) and then bought a standard set of Bosch Motorsport leads that I cut up to suit.

[Tonyorlo]

Hybrid, do you happen to know what type of wire you are using?

[hybrid]

I don't know exactly what type they are - can't find any info.
But I went for the Bosch Motorsport range because they specifically mention better EMI/RFI suppression.

[Tonyorlo]

Today I verified the exhaust was tight, coil wiring is correct and I still have the same problem. I figured before I pull all the wiring out I will try new coils, but that did not fix it. Tomorrow I will try OEM wires, and if they aren't the solution then I will most likely install a HEI distributor. I am completely lost, I wish there was some local support but I am 60-70 miles from the closest shop and they all specialize in Mitsubishis.

[Tonyorlo]

Well I tried new AC Delco plug wires today with no luck.

Could it be possible the tune is in correct or has a flat spot in it to cause it to backfire?

Say I try a distributor in the engine, will I need to reverse all of my mods for the logic type coils?

[Tonyorlo]

Chevellefan (Dave) suggested something that makes a lot of sense. If I do decide to go to a distributor, I can keep my crank trigger and use the distributor just to direct the spark. Say I do that, can I use the signal from the distributor so I can go sequential on the fuel?

Will I need to make any changes to my ECU?

[ChevelleFan]

Tony, one other thing you could try, since you've already got the crank trigger, and it looks like you were trying to use LS coils mounted remotely (ie, not on the valve covers) would be the VW coils for running a wasted spark setup. The spark plug connector at the coil end is the same as your LS coils. You'd need a small amount of rewiring on your SpkA/B/C/D outputs, but you'd still have the wasted spark setup you were trying for. The VW coils can be had at Autozone for ~$30-35. You'd need two of them. This is the path I'm considering taking.

http://www.msextra.com/forums/viewtopic ... 71&t=66260

http://www.msextra.com/forums/viewtopic ... 71&t=66803

http://www.msextra.com/forums/viewtopic ... 01&t=49837

-Dave

[hybrid]

Chevellefan (Dave) suggested something that makes a lot of sense. If I do decide to go to a distributor, I can keep my crank trigger and use the distributor just to direct the spark. Say I do that, can I use the signal from the distributor so I can go sequential on the fuel?

Will I need to make any changes to my ECU?

You can't run sequential on a V8. Not enough outputs to separate out each cylinder individually.

[rickb794]

Is it possible you have something interrupting the power to the coils?