05gto60

iTrader: (3)

Ive been chasing around a misfire for a little while (stopped driving the car a long time ago, just didnt have that much time to work on it). anyways, this was the thread I started before.

https://ls1tech.com/forums/generatio...fire-help.html

I eventually went back and compression tested each cylinder again. When I got to cylinder number 4 (the one with the mis) I noticed it built compression on 1 or 2 strokes and then stopped. I released the pressure, tried again, and same thing happened. After some deliberation, the only thing i could think of was a bad lifter.

Turns out I was right, but not like I had hoped. much to my dismay I found that the intake lifter (LS7) had ground the roller down a bit. The cam is out and I have new lifters here (Morel link bars) but will be waiting on a cam and pushrods. Im going to throw the cam back in tomorrow and measure pushrod length on another cylinder and order pushrods the same time as the cam. I am planning on using the same grind on the cam since i dont have access to a dyno or tuner over here.

I think this may have been slowly happening since about a year or so ago. I had a valve spring break and I'm about 90% sure it was on that valve. Since I changed the springs out this is the first problem I've had.

fuel

iTrader: (13)

got any pics of the cam....

05gto60

iTrader: (3)

I didnt take any but still can. Its still out of the motor. The lobe looks a lot like the roller on the bad lifter.

ringram

Bearings might be munched up too. Mine were, similar issue, though my lifter died big time. Stopped spinning and wore flat.

05gto60

iTrader: (3)

Heres a shot of the worn lobe. it looks a lot like the roller part on the lifter.

05gto60

iTrader: (3)

Ill try and check them out but (hopefully) there wont be any damage. this roller was still turning, just not in a circle.

briancb1

You can bet the bearings have wear. With the spring pressures we run with these cams, it's part of it.

05gto60

iTrader: (3)

Id need to look at the exact numbers, but the motor only has about 12K-15K on it. It was built the begining of 09 and had been down waiting for a transmission for a while. Replacing the cam bearings over here in Italy is not an option though.