Misfiring
Thread Starter
6th Gear
Joined: May 2019
Posts: 6
Likes: 0
Misfiring
So i have a 2002 Z06, code is P0300, new plugs, wires, cleaned injectors, checked valve springs, checked my coils, everything was fine but i’m still misfiring, any tips? should i just go ahead and do a compression test and leak down test? could it be the crank or cam sensor? car runs and drives just misfires and is super rough. Mods are TFS 215 heads, shorty headers, AFE intake, and a tune. cars been fine the past 7k miles so i don’t think it’s a tuning issue.. any tips?? thanks in advance.
Administrator
Joined: Mar 2001
Posts: 367,781
Likes: 24,683
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '25
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
Moved to C5 Tech.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,435
Likes: 3,981
From: Cape Coral, Florida
Kyle, sorry to hear you are having misfire issues...I'm assuming you used the DIC to pull codes but unfortunately they will not show what cylinder....without a scan tool and some specialized equipment it will be somewhat more difficult to diagnose....I'd say around 75% of misfires are ignition related...how did you check your coils BTW ???...have you ever done a cylinder drop test ??...you can start there by determining which hole or holes are "dead" and are not contributing...so you cleaned the injectors but do you know they are functioning correctly ??...if you had a scan tool we can look at fuel trims and see if it is a fuel or ignition misfire....you can do a compression test to rule out anything mechanical...even bad prop shaft couplings can cause these P0300...as far as the injectors you can ohm them out and make sure that you have injector control by using a test or a noid light...don't know if you know how this is done ??...I always do a cam/crank correlation for misfires but you need a scope to do this test.
Last edited by C5 Diag; Sep 6, 2019 at 12:48 PM.
