Misfire cyl 2

[bealszac]

99 5.7 vortec I am having a misfire on cylinder 2 and an occasionally multi cylinder misfire. I have put new cap and rotor,new spider injectors, plugs wires. Have spark and fuel pressure what also may cause this? Intake gasket was replaced by previous owner a year ago. I apriciate it.

 

[SUBURBAN5]

Do you have a good scanner?

 

[Boyder102]

I have 98 5.7, same parts change and fuel filter.
I get cyl3 misfire when I hold rpms above 2200 under load.
Can’t figure this out either,

 

[Schurkey]

What is the cranking compression pressure of each cylinder (especially the ones misfiring.)

As was said on another thread about misfire--are the valve springs good? Do the valves stick in the guides under load? Apparently GM has a bulletin on sticking valves under load, the "fix" is to remove the valve(s) and hone the guide(s) for some additional clearance.

Before I did that, I'd be VERY careful to assure that there's no ignition or injector issues.

 

[bealszac]

What is the cranking compression pressure of each cylinder (especially the ones misfiring.)

As was said on another thread about misfire--are the valve springs good? Do the valves stick in the guides under load? Apparently GM has a bulletin on sticking valves under load, the "fix" is to remove the valve(s) and hone the guide(s) for some additional clearance.

Before I did that, I'd be VERY careful to assure that there's no ignition or injector issues.

all cyl have good compression and within range of each other. i did not have this problem 2 weeks ago. i was hunting down another problem and changed everything out listed above. once i started it i got the misfire.not super noticeable at idle I definitely feel it being a bit slugish. i checked spark and plugs and that seems good dont really have the tools to check injector so i pulled the plug and just scoped it after cranking to check for fuel and there seemed to be plenty. im kinda at the point of a intake leak? maybe valvs? but my compretion would be worse. kinda stumped at this point.

 

[Schurkey]

New misfire immediately after replacing injectors? I'd be concerned you have a defective injector set.

 

[bealszac]

New misfire immediately after replacing injectors? I'd be concerned you have a defective injector set.

i was hoping that wasn't it i really didn't want to have to pull that thing again.