icicleboy

Hey all,

so we've got this LS4(FWD) turbo that is making great horsepower, probably in the mid 400's at the wheel through an auto trans. Our only issue is a random misfire which doesn't happen ALL the time, but happens often. Generally happens at 5000rpm or so (4900ish). So far, I've increased the dwell bit by bit up to 6ms, and have installed fresh autolite 104's @ 0.025 to see if it would cure the issue. Still has the issue. I can't imagine that these coils are any different then any other lsx, and am just not sure what else could be the issue at this point. Car runs about 10psi, and utilizes alky injection (50/50 WW fluid).

Any input or suggestions would be greatly appreciated.

brandon619

iTrader: (1)

What kind of plug wires are you running? I just had the same problem on my Procharged Z06. I had two problems when I removed the headers and cracked a couple of plugs. Then replaced them and still had a slight miss up top like you. Then I replace my 8mm MSD wires with some 10mm Taylors and problem was fixed.

icicleboy

Still running stock wires... I was hoping that stock wires would suffice though?

brandon619

iTrader: (1)

I would change those stock wires.

icicleboy

hey guys,

thanks for the responses. Are you suggesting to change the stock wires for something aftermarket? or just change for fresh stockers? I'm used to the GM DIS 2 plug/coil system that can actually support well over 500whp on stock wires/coils. Are these individual coils/wires not as strong? Are forced induction people on this board all running aftermarket wires with over 400whp?

Thanks again

LS1curious

I can;t see either the wire or the plug being the problem. Turn up that dwell to around 10-15ms. I have seen some of the coils be sensitive to problems with dwell. the other possibaility is Knock Retard.

icicleboy

All the data I've read has said that the lsx coils won't stand up to much more then 6ms without overheating and dying very fast. Stock was about 3mS. There is no KR. none ever.

Thanks again

1fstTA

iTrader: (25)

I had a miss at around 3500 and up but it was 2 bad msd coils and the plug gap was to wide we regapped to 27 and replaced the 2 coils and it ran like a champ. Now it just pushs water like crazy.