Multiple Misfire P0300

schardbody · 06-27-2011, 10:44 PM

i'd recommend a compression and leakdown test aswell.

i've seen multiple LS injectors fail causing the same problem, so if you're up for it swap the injector with another cylinder....

it could be many things if its mechanical, not just a valve spring, valve seat could be beat up, valve could be hanging up in the guide, or it could be bent (would likely get a misfire at idle with most of those problems though.

i doubt its a plug, honestly i've never seen a plug have an issue at WOT only in N/A applications, but its worth a try before going any further.

06-27-2011, 10:44 PM	#20
schardbody Senior Member Join Date: Sep 2008 Posts: 1,158	i'd recommend a compression and leakdown test aswell. i've seen multiple LS injectors fail causing the same problem, so if you're up for it swap the injector with another cylinder.... it could be many things if its mechanical, not just a valve spring, valve seat could be beat up, valve could be hanging up in the guide, or it could be bent (would likely get a misfire at idle with most of those problems though. i doubt its a plug, honestly i've never seen a plug have an issue at WOT only in N/A applications, but its worth a try before going any further.