Help:LS1 misfire(FIXED)

Okay, got arm deep in the beast.

Checked all the grounds, they were bolted on tight and there was no visible damage to any of the wires.

Checked all connections. Plugs were all snugly fitted in the block, as were the wires to the plugs, and wires to the coil packs. The coil pack harness was also firmly fitted.

Therefore:
I decided to tear out all 8 spark plugs. About an hour later, hurting back and swollen knees(Thank you GM for putting the engine overly towards the back of the car…)

I made a discovery.

7 plugs looked like:


1 plug looked like:

That shiny platinum plug has been in the engine as long as the rest. Thats plug number 6, the gas smelling one.

This leads me to believe:
a.The harness is bad
b.(more unlikely) the injector on cylinder 6 is so clogged/broken that there is absolutely no fuel getting into that cylinder.

Both of these situations may be why the computer can’t lay down a code for me… Because there is no harness broken/injector clogged one haha.

Hopefully I got it this time.

Also, while tearing into the engine bay I discovered where a loud ticking noise was coming from. Apparently, when I took off the pipe connected to the header I shred the gasket… Ooops.

You realize an exhaust leak will fuck shit up?

Try another switching coil packs around?

I have no exhaust leak… Unless your referring to the EGR pipe which i will replace.

There’s already a new coil pack there… Both the old and the new aren’t firing that spark plug…

Hence, why I think the harness may be fucked up.

You probably have a bad ground somewhere…like Studderin said…

I will give you $3000 for the car :tup:

… Did you honestly read anything I posted?

Since all the plugs, wires and coil packs are good.

And the grounds are all good.

The only thing left is this harness must have some sort of defect because cylinder 6 simply isn’t firing.

call me up sometime ill come over and help you out.

Thanks man.

I’m having firehawk853 scan the beast today at his house, but when it comes down to actually doing the dirty dirty with the engine I’ll be sure to give you a call.

What a fucking day!

Cliffs: A great group of F-body fanatics saved the day. LS1=Fixed.

Long ass day, started off with me driving to cheektovegas to see Firehawk853. We took the car out for a run on Walden Ave with his HP tuner software hooked up. Ran a lot of tests, all which panned out to be nothing out of the ordinary. No timing being pulled, nothing funny.

We decided to do some WOT testing to see if we could cause anything to be red flagged on the diagnostics test. Second gear, doing about… 30mph, to redline… We passed a cop… Fuck. Turns out i was doing 66 mph in a 45, and my exhaust was insanely loud. Cop let us off because we explained to him we were just trying to figure out the problem with my car! Yay depew PD.

Then we went to “the shop” and met up with Jay who had a set of 28lb injectors. We exchanged injectors and ran it again… No luck the car was still flashing the god damn SES light. We compression tested it… Car got a whopping 25psi on cylinder 4. Either meaning my piston/rings were fucked or my pushrod was destroyed. Took off the valve covers and turns out my pushrod had broken in two! Mind you, its a basically stock ls1 with a exhaust on it, and I’ve never done anything ridiculous such as over revving it or downshifting and missing the gear i was aiming for.

Jay had my back. Jay had the stock push rod in stock.

Plopped that sonova a bitch in and what do you know, no SES light! It’s great having a ls1 8 cylinder instead of an ls.9 7 cylinder.

Big thumbs up to Jay, Bill, Chuck, and Pat!

Thank you so much guys. Dinner when i get my refund…

Edit: Heres that pussy pushrod that couldn’t handle the vtec produced by the ls1.
“nom nom nom valvetrain hungry!”

Glad we could help buddy. how was it on the way home? drive way better? more power?

Felt like a brand new car.

Completely different, that pushrod must have been like that since i’ve owned the car and I just never noticed it.

It’s fucking awesome. And I don’t have SES light induced seizures.

If you ever need a shop slave lemme know, I’m down to give any of you guys a hand anytime!

:tup: for J & J Speed Shop having pushrods in stock on a Sunday night to fix this problem

AMEN.

:tup: good stuff man… bet that was a relief from possibly needing a new bottom end to just a pushrod :lol:

I was thinking about that as I was filling my car up at the mobile…

It felt like the excitement I had at Christmas when I was 7. I honestly don’t know what I would have done. My firebird is my DD for now, so I woulda parted it out I guess.

just read the thread, glad you got it fixed!

it must have bent/broke since you have had it as the SES never flashed when I had it and it pulled strong, you did miss 2nd when you pulled out of my driveway with it : P

gotta be careful with fbods, they love to eat pushrods, even A4 cars have been known to bend/break them

ah well, its the price you gotta pay to have an engine that was touched by the hand of God!

glad shes running tip top again and hopefully when the weather cooperates you can enjoy it all the more!

No?

I took it so easy driving home not registered or insured that’s impossible.

:tup: :tup:

Since when?

Usually this happens from mis shifting…

Glad to see its fixed, this is your first LS car? Im surprised you didnt feel that it was running on 7 cylinders.

I was worried I may have bent one on my old Formula and searched around ls1tech and found that alot of people with A4s had bent/broke them

some of the cars were stock no less