Settings correct to detect misfires

[Guy With A Chevy]

Anything with these settings wrong to detect misfires?

[Guy With A Chevy]

Everyone says they dont see the problem I am describing. One of the clear indicators of the bucking/hesitation is the RPM fluctuations in this short export where I am accelerating.

[GHuggins]

This has your misfires back reporting. I also pulled some timing - put parts back to stock - can always change back. Really thinking something is mechanically wrong right now. Log misfire history and current.

[GHuggins]

Looks like possibly a miss on bank 2. Map kpa goes up 1 kpa, you can see the rpms change slightly and right afterwords bank 2's O2 stays pretty low. I wasn't logging the O2's as a line to know for sure to know if it was just one bank.

[Guy With A Chevy]

Thankyou so much for noticing the changes you made GHuggins I have a clear problem with #7 going to start swapping things.

Been driving it this way for awhile

[Guy With A Chevy]

I'm down to injector or wiring... this freeze frame telling me theres a wiring issue could be it

[GHuggins]

That's just saying the alternator may not be charging. Gotta fix that too, but... Probably easiest as it doesn't take 10 minutes to do is to just swap the injectors.If you have a noid light check that quick first of course. You do have a dead miss on cyl 7 - boy was I wrong on the bank Think it's 4 8mm headed bolts or nuts then some connectors and out she comes. May even have trash stuck on top. They were bad for rubber in lines coming apart and getting stuck in the top of the injectors. Tap 7 on a clean towel to see if anything comes out.

[Guy With A Chevy]

That's just saying the alternator may not be charging. Gotta fix that too, but... Probably easiest as it doesn't take 10 minutes to do is to just swap the injectors.If you have a noid light check that quick first of course. You do have a dead miss on cyl 7 - boy was I wrong on the bank Think it's 4 8mm headed bolts or nuts then some connectors and out she comes. May even have trash stuck on top. They were bad for rubber in lines coming apart and getting stuck in the top of the injectors. Tap 7 on a clean towel to see if anything comes out.

many times
I am familiar with them I know its a cake walk gonna eat something and go swap injector 1 and 7 around thanks to your push

[Guy With A Chevy]

Swapped injectors still on 7. Valvetrain seems quiet enough doubt its a lifter but I will take off the valve cover tomorrow and roll it over by hand to confirm. If there was a loss in continuity on the #7 injector circuit it would throw a different code right? So the injectors share a common hot and the ecm controls the ground. Just learned what a noid light is might pick some up tomorrow

[GHuggins]

If a pushrod wasn't installed into the lifter correctly it'll hold a valve open and it is possible to kiss. Got an engine from a builder one time where the pushrod was off to the side jammed in the block holding the valve open. It would be obvious though - valve not opening or closing.

It's also possible to bend a valve causing one to stick open during head torquing. Had a guy across the shop from me do that. Socket was rubbing the valve spring while he was torquing the head bolts. Was apparently enough to bend the valve just enough.

May even be the ecm not firing the injector or something wrong with the computer in general. Never know.

[Alvin]

Swapped injectors still on 7. Valvetrain seems quiet enough doubt its a lifter but I will take off the valve cover tomorrow and roll it over by hand to confirm. If there was a loss in continuity on the #7 injector circuit it would throw a different code right? So the injectors share a common hot and the ecm controls the ground. Just learned what a noid light is might pick some up tomorrow

I deal with a lot of random misses that turn out to be wiped cam lobes. One in the shop right now for exactly that.. and quite a lot don't make any noise. This one didn't and I counted 4 lobes with good damage.

I'm personally not a fan of using misfire diag stuff on cammed cars as it can easily send you down a wrong road. Are you sure that cylinder is dead? A cheap children's squirt gun is super handy finding misses. Works way better than a IR gun.

[Guy With A Chevy]

I deal with a lot of random misses that turn out to be wiped cam lobes. One in the shop right now for exactly that.. and quite a lot don't make any noise. This one didn't and I counted 4 lobes with good damage.

I'm personally not a fan of using misfire diag stuff on cammed cars as it can easily send you down a wrong road. Are you sure that cylinder is dead? A cheap children's squirt gun is super handy finding misses. Works way better than a IR gun.

I already plan on checking for glitter this morning in the process. Water evap test! Water stays on the header its missing, good stuff thank you Sir

[Guy With A Chevy]

No glitter in the oil. Took off the valve cover to confirm no rocker play just to be sure. Fired it up and squirted water on bank 1 and #7 stays nice and cool. Noid lights sound good but I rather find a shop with a bore scope plan to call around right meow.

I dont think its the coil leads from the ecm I shocked the crap out of myself yesterday with the #7 coil and the spark plug was almost dead white

Im going to have a hard time finding a shop might just get some noid lights...

I have read alot on the wiring of these trucks. The grounds I have are under driver, driver side of block near knock sensor, under radiator ground and a final ground that attaches to the front of bank 2. The rear of bank 2 has a ground that connects to the firewall. I never had a hood static ground and there are no grounds on bank 1 directly. Is this an issue?

[Guy With A Chevy]

Right after I bought the truck I had an issue while driving through Nevada where I floored it doing about 75 to pass a trucker. The driver side catalytic converter melted down into the bottom of the bubble causing bank 1 to kick so hard it cracked the fan inside of the torque converter thats when I did my first transmission and top end rebuild and found helicoiled cylinder head bolt holes and the intake glued on(everything had sealant I had to beat/pry the pan off). I personally bought the truck from a friend that got it from Bros Auto Sales in california and I swear it was them that did the janky stuff I found. That block is history got about another 10k out of it before a cam bearing went bad. Found shiny performance bi metal cam, crank and rod bearings not the soft OEM ones as the block had already been rebuilt with less than 120k on the truck when I bought it. This is a new block

Now after learning this side of the of the fence im guessing its an electrical issue

[GHuggins]

After checking the injector with a noid light, do a compression and running compression check. I assume valves were moving - opening and closing? No cracked or broken valve springs - use a mirror to go around them.

[Alvin]

No glitter in the oil. Took off the valve cover to confirm no rocker play just to be sure. Fired it up and squirted water on bank 1 and #7 stays nice and cool. Noid lights sound good but I rather find a shop with a bore scope plan to call around right meow.

I dont think its the coil leads from the ecm I shocked the crap out of myself yesterday with the #7 coil and the spark plug was almost dead white

Im going to have a hard time finding a shop might just get some noid lights...

I have read alot on the wiring of these trucks. The grounds I have are under driver, driver side of block near knock sensor, under radiator ground and a final ground that attaches to the front of bank 2. The rear of bank 2 has a ground that connects to the firewall. I never had a hood static ground and there are no grounds on bank 1 directly. Is this an issue?

That's the rub too.. I"ve never seen anything unusual in the filter with a wiped cam. I know that sounds crazy but I've done it several times suspecting a cam... doing a filter cut and not finding anything

[Guy With A Chevy]

I dont check the filters usually I did one time just to be sure but the glitter in the oil has always been a clear indicator.

Im super happy to report back it was an abused spark plug. I knew mechanically something was up driving it the last month even included a 6-700mile round trip. I will say I am cheap and I need to stop being that way!!! The spark had ever so slightly been cracked not removing the headers last head removal and I sure paid for putting it back in. I was so happy to feel solid acceleration when she went into torque lockup I have not a clue how I missed that yesterday. Thank you again Ghuggins & Rabbs88 you were 100%correct would have continued running in circles chasing my own tail.

I can also say I feel alot more confident in tuning now I know I still have ages to go. Literally answers all the questions of what was wrong. I will remember this one forever!!!

I apologize for dragging everyone into this over my carelessness. Was it the P0300 you changed to mil on second error?

In the long run it gave me a jumpstart as I direly wanted to tune the problem out and have spent almost all my free time trying to learn. I am thankful for those that insisted on the misfire!

[GHuggins]

Man sometimes it's the simplest of things. Honestly I thought you had checked that already, but we do all overlook things from time to time. Glad it was something simple and now you can finish her up I was worried about valve train just from what I've seen over the years with head installs and everything else.

You can use the compare function, but I changed your misfire settings in the diag section. They were set up to not report at all before. You can either raise what's in it now about 50% so it will still report in the future or kill it again all together.

Go easy with putting the timing back in. She was up there before, but may have been ok all things considered. Just go easy with it.

[Guy With A Chevy]

I'll even be more honest about the mistakes I made with this transplant earlier this year.

In the process of pulling the old block one of the trans lines were bent as it somehow one got re caught on the side of the block while raising it another 6 inches which is still causing problems but I have a remedy ready just need the time to come up.

The mechanic I got the block from was in a rush and gave me 3.980 bore head gaskets instead of the 4.1 for a 6.0 bore. Luckily it wasnt ran past idle more than 2x and swapping in the proper gaskets solved the pistons hitting the gasket noise.

I was also told by this mechanic you could bench test oil pressure by having the valvetrain in with no rockers installed and you will get oil pressure(Should) I chased this for a week before figuring out you have to have the rockers applied or the lifters will raise too high and the oil pressure will come out of the bottom of the lifter bore.

I am so relieved I thought this was one of those hidden compression issues

Initially I just did a dod delete tune. I ordered a used non DOD valley cover that had the trays included. I never compared the newer looking trays to my old trays I just slapped them in on top of non dod lifters. Turned out the trays were stock and letting the lifters chew up the cams by not walking straight. I have the correct trays now. One cam was ruined this way earlier this year and I was not afraid to admit another one but the glitter was not present. With all these mechanical problems it was easy to overlook a hairline crack in a spark plug.

Also seems it has solved the generator field issue