Thread: Heavy Isolated Misfire Under Load

@%!*!

The only thing left is the lifter or the injector.

The lifter looked fine compared to others. But who knows if its actually pumping up or not.
I probably should have swapped the lifter to another cylinder to see if the miss moved.

And I don't think it can be the injector because the problem started immediately after the rocker install.

Any ideas?

i thought you were gonna pick up a lifter. i would have swapped it.

maybe its best at this point to fire it up vc off, see what that rocker is doing. maybe you can see or feel the push rod not being tight due to a bad lifter.

I don't think the parts store has them. Or else I would have picked one up.

Is is to safe to fire it up with out the valve cover?

Yup just expect a little oil might spill out onto the manifolds/ or headers

they used to sell clips that kept oil from shooting all over. you could lay a rag over them.

when i rebuilt my firebirds 400 i fired it up v/c off and it shot oil 20 feet up and hit the side of the house. it was crazy, 8 fountains of oil pumping at the house. that was fun to clean up i tell you.

Yay that sounds really safe

Damn Joe. Yeah I would fire it up without the valve cover, see what happens.

Joe I still have those 4 LS7 lifters, when you go to install the lifters, soak them in a bowl of oil first.

Also...really crazy thought and for ****s and gigles; put the stock rockers on the front bank.

Lets recap what you have done and just check off what you have done:

-New spark plug
-new spark plug wire
-new coil pack
-swapped injectors
-check signal to said injector
-check ICM
-check valves
-check rockers
-check pushrods
-check lifters

Is it remotely possible the cam was damaged from the missing spacer?

Originally Posted by Drunkie

Lets recap what you have done and just check off what you have done:

-New spark plug Check (swapped with another cylinder; no change, still cyl 1 miss)
-new spark plug wire Check
-new coil pack Check ( swapped coil packs around; no change, still cyl 1 miss)
-swapped injectors Haven't done this yet
-check signal to said injector Haven't done this yet
-check ICM Check
-check valves Check
-check rockers Check
-check pushrods Check
-check lifters Check ( visually checked, but who knows if its actually pumping up)

Originally Posted by 4THGENCAMAROFAN

Is it remotely possible the cam was damaged from the missing spacer?

I've thought about this, I peered down at the cam when i pulled the lifter and it looked fine.



Im thinking its not spark or fuel related because the problem occurred immediately after the rocker install. The car hasnt ran right since I put them in.

I leaning towards the lifter now.

Do the injector swap around, takes 15 minutes.

Ill swap the injector. Then ill pull the vc and see what going on, not that ill think ill be able to really see anything. After that I suppose ill swap the lifter out for a new one.

You said the car is idling high? That still happening? if so.. you likely have a huge vaccum leak.

No all the weird things going on stopped when I fixed the coolant temp sensor.

How about taking a 194 bulb and putting it into the injector plug just to make sure the injector is getting power/ground. You should see a flashing light when it's running.

It only happens when I give it gas/go into boost.

You think that my injector would stop getting power when I get on it?

No, I thought it was also idling badly

I think you need to pay Scotty to come fix it.