p0305 cylinder 5 misfire

**ls1alltheway** · 03-14-2007, 05:19 PM

help!!!! it'driving me crazy replaced, plug replaced wire, checked connections, moniterd the system and watched it misfire! all is lost please help.

**mrr23** · 03-14-2007, 05:26 PM

swap coils around and see if it follows.

**ls1alltheway** · 03-14-2007, 05:39 PM

that was my next plan of attack.

**2001hawk** · 03-16-2007, 12:55 AM

Hey I have been there. Let me share with you my story, about a year ago my firehawk was throwing random/multiple cylinder misfires. It had gotten really bad to the point I could drive it around no problem and then it would start bucking and acting crazy. It was worst at around 1,000 rpms in sixth gear. Sometimes it would throw a certain cylinder (say #1) misfire. At this point I would move the plug to cyl. 3, the plug wire to #5, and the coil pack to #7. Then after cranking it up the misfire would move to say #6. At this point NOTHING will have you more pissed trust me. I am like I didn't even touch that side of the damn motor.

Finally I got tired of getting nowhere and carried it to a shop and they changed the plugs, wires, coil packs getting nowhere. Everytime the misfire would show up somewhere else. It turned out to be the computer. That cost me what I thought was a lot at the time, but in the end considering they didn't charge me for the troubleshooting time I got a hell of a deal. In the end the guys were real cool I take both of my LS1's back if I don't have time or can't figure something. It always can be worse. LOL. Keep your head up.

**ls1alltheway** · 03-16-2007, 01:05 AM

yeah a friend of mine owns a shop and i'm going to drop it of on saterday. and hopefully they can fix it for me. i just don't have the time or patients. i kinda figured it's either a bad computer or burnt valve. either way it's going to be big $$$ to have it fixed.

**ls1alltheway** · 03-16-2007, 01:07 AM

oh yeah i did try swapping coils around and it still has the miss on #5 but it also started a random misfire on various cylinders. but only when in N and idleing at 3000 or so. mind boggling......

**2001hawk** · 03-16-2007, 01:35 AM

Actually the shop that I carried my firehawk to charged me around $600 I think for the new plugs, wires, computer and programming. It is a 2 hour programing session at the dealer, but the mechanics brother or brother-in-law works at the dealership. So I only paid whatever the least possible. I have worked with this shop several times since then and they have always done right by me. That is real important to me since my cars are what they are I want someone local that I can trust.
BTW both are head and cam LS1's

**Chevythunder17** · 03-22-2007, 09:02 PM

Perhaps an injector issue?

**ls1alltheway** · 03-24-2007, 03:02 PM

dunt, dunt da..... i found the problem, broken push rod!!! so as a heads up for any of your do it yourselfers. spend the money on chrom-moly push rods. i kinda feel like a dumnass for missing this. oh-well go figure. so thanks for all the suggestions.

**0rion** · 03-24-2007, 04:19 PM

When reading this the other night I kind of wondered if it could be a pushrod issue but you still hadn't checked the injectors so I thought it very well could be an injector. Either way, glad you fixed it and I love a happy ending.