VandykeT/A

My car has a part throttle light miss in it. And by light I mean to the point where you think its normal (MS4 cam). If you give it say half throttle in high gear between 2k and 3k you can feel it for just a second and then it clears up. Another thing that makes me wonder is I can't tell if occasionally I'm hitting the rev limiter or if I'm getting an erratic miss on top end. It feels almost like the limiter comes on sooner than other times. Does that sound like a coil going bad?

angel71rs

Could be a bunch of different things, like plugs, wires, bent valve/push rod, valve spring, etc. Coil test procedure in this thread if you want to check them:

https://ls1tech.com/forums/new-ls1-o...oil-packs.html

If you have an android phone, highly recommend Torque app. 5 bucks, buy an adapter, you're in for under $30 and much better than guessing when trying to zero in on problem area. I use this adapter:

TXsilverado

iTrader: (18)

stick your finger up the plug wire and have someone hit the key.

VandykeT/A

I actually had the heads off the car less than 2 monthes ago and I've maybe put 2k miles on it. The pushrods are new, all the valves were replaced, the springs were checked and 1 replaced because an inner one was broken. Plugs and wires are also new. It did it before the heads were pulled. And I don't think I'll be putting my finger in the plug wire lol.

TXsilverado

iTrader: (18)

i dont know how else to check it then...i guess a toe would work too or your...never mind

VandykeT/A

Next time we have a weiney roast I'll think about it lol.

thunderstruck507

iTrader: (18)

When you say you checked the springs do you mean for pressure or visually?

My guess is weak valvespings or a lightly burnt plug wire.

VandykeT/A

I mean I checked visually. I had a problem with the valve tips wearing and when I pulled the heads to replace the valves I found that 1 valve spring was broken. I replaced it and didn't think anything of it thinking it came from the wrong pushrod length. They have less than 5k miles on them and they're the springs that came with the PRC 215s all ready assembled. The way the car acts its like it slightly loads up with fuel at low rpm when you lug it around and then when you give it alot of throttle from 2k to 3k it clears itself out. Its so faint I always thought it was normal. What are the odds it is my valve springs?

garygnu

mite also be wrong lifter preload.ideal the engine in the dark with the hood open and check for any spark.test and change spark plugs.how many miles on the valve spring ? probably some wet wire that need to be dried out.

VandykeT/A

I measured for pushrod length and ended up with a 7.475 all with TSP on the phone explaining exactly how and they even did the math. He added in 0.050 preload. The valve springs have probably 5-7k on them other than the 1 new spring that replaced the broken one. Spark plugs were replaced when the heads were taken off less than 500 miles ago and the wires might have 3k or so on them. Now that you said wet wire. Would not having my ecm seals in cause this? The car doesn't do anything else weird. Whenever the guy that orignally did my heads took the computer out for me to have a mail order tune he didn't put the seals back and its been that way ever since.