Tri5Nerd

iTrader: (3)

I've been reading a lot lately where folks say that a engine could be running on 7 cylinders, and to check if all cylinders are firing.
Pardon my lack of knowledge here but just how do you check that?
I think checking the plug wires is one part, what else needs to be done to manually check?

drz

iTrader: (3)

It's pretty easy, really. While the engine is running, pull injector clips one at a time and listen to see if the engine starts running differently. when you pull one and the engine is unaffected, you've found the cylinder that's not firing.

Z28LS1camaroguy

iTrader: (3)

you can also pull a plug wire and turn it over and see if it sparks.

drz

iTrader: (3)

I've seen a few occasions where an engine has sat for a while (like when waiting on parts, or a new short/long block), and when it's finally fired up again, one or more of the injectors is stuck closed from having sat a while. Pulling the clips as outlined above will isolate the stuck injector(s), and a soft tap with a hand tool is all it took to free them up. Big cams with a lot of lope can mask a non-firing cylinder, especially when newly installed and the owner/operator isn't familiar with the engine's good-running sound.

Tri5Nerd

iTrader: (3)

So, most times the cause is that a injector(s) is closed or there are no spark from the wire?

Is there any other manfunction that could cause this probelm?

drz

iTrader: (3)

broken parts such as:

bent valves
broken rocker arms
melted/perforated pistons (too much juice, yo!)
blown head gasket
etc.