P0300 and hesitation going up hills

[Meccanoble]

In the Torque Pro app go into Settings > Manage Extra PIDs/Sensors > press the 3 dots at top right of screen > select Add predefined set > Pontiac/GM/Opel/Vauxhall

Now scroll down about 40-45 PIDs and you will see this...
View attachment 249517

They are not in order... I don't know why... but all 8 cylinders are available.

I ended up upgrading to torque pro and I see everything you were discussing but not sure how to enable? I just have option to edit/delete and test.

 

[Meccanoble]

I played with it and looked at videos. I should be fine. Hope to send a screen shot of my findings.

 

[Meccanoble]

Wow this app is useful. So I just took the truck for some spirited driving and seen misfires on all cylinders but I think there is an amount that is considered too much. History shows the following after a 5 minute spirited drive:

Cylinder 1 - 52
Cylinder 2 - 15
Cylinder 3 - 877 ***
Cylinder 4 - 2,269 ***
Cylinder 5 - 2,076 ***
Cylinder 6 - 8
Cylinder 7 - 595
Cylinder 8 - 440

I am waiting for truck to cool down so I can check the spark plugs. I'm assuming Cylinder 4 and 5 are definitely an issue while Cylinder 3, 7 and 8 are potentially on their way? Cylinder 1,2, and 6 are fine? Look forward to your feedback and what else I should check. If plugs look good, i'll go after coils & wires.

Also, the cylinders start from passenger side closest being 1 and 8 being the farthest from the driver on the driver side?

 

[Meccanoble]

Ugh, was hoping that 8 cylinder had no issues. I guess I have bigger fish to fry anyway.

 

[Rocket Man]

I would start by working on 4 & 5 by pulling those plugs. Inspect the plugs, and if they look ok reinstall them but inspect the wires. If they look ok, swap the wires from 2 & 3 and go for another drive or just start it up, clear history and see if the problem followed the wires. You might be getting misfires on 7 & 8 as a result of what’s going on with 4 & 5. Or your problem might be something else like cats. You can also try the same troubleshooting with coils by swapping them but just do one thing at a time.

 

[Meccanoble]

Thanks, thats very helpful

 

[Meccanoble]

I checked plugs and the bad cylinders seem to be the same as the good cylinder. Took pics of 2, 4, and 5 and they all look the same. I'll share soon.

I swapped wires between 4 and 2 and 5 and 1. The numbers are weird. Looking for suggestions on what to switch next.

C1 - 0
C2 - 2
C3 - 7
C4 - 1
C5 - 28
C6 - 0
C7 - 875
C8 - 43

I inspected all wires though I dont know what I'm looking for. When connecting to the coil pack, you tend to hear a double snap for confirmation its plugged in.

I didnt do any swaps with C7 yet its the worst....

C1 is consistently low so the C1 coil pack and C5 wire seem to be fine. C5 coil pack might be an issue.
C2 consistently low so the C2 coil pack and C4 wire seem to be fine.
C3 seems to be ok now, maybe wire was loose.
C4 no longer giving an issue. Maybe something was loose. Using C2 wire and no issues.
C5 still a little high? Its now using C1 wire so possibly bad coil pack?
C6 is consistently low and not an issue.
C7 now the highest. Will need to check plug but will probably swap wire with C1 to see what happens, then coil pack.
C8 second highest. Might be because of issues in C7.

These are my thoughts but I look forward to your suggestions.

 

[Meccanoble]

Here are pictures of plugs. Top is 2. Middle is 4. Bottom is 5

 

[Fless]

Way overdue for new plugs. Hardly any center electrode left, and huge gaps. SMH


EDIT: I think you got the same knockoffs as @kbuskill had. Actually, they look like plain old copper plugs. No longevity.

 

[Meccanoble]

Way overdue for new plugs. Hardly any center electrode left, and huge gaps. SMH

LOL well that does it. 100k miles my @$$. Ordering plugs now

 

[Fless]

What numbers are on the old plugs?

 

[Meccanoble]

Any reason I should go for AC Delco 41-162 or am I still ok with 41-110??

 

[Meccanoble]

What numbers are on the old plugs?

41-110

https://www.amazon.com/ACDelco-4111...ade+by+ACDelco+(8-pack)&qid=1591663111&sr=8-1

 

[Meccanoble]

I havent put 100k miles on the truck yet and definitely waited a while through ownership before I tackled this job due to the dreaded 8 cylinder. Anything that would have caused them to go sooner than usual?

 

[Fless]

I don't think I can speak to that. The iridiums I pulled out of mine at 100K could have gone at least another 60K or so, hardly worn. But I changed them anyway since that's the maintenance interval. All I can think of is that you got knockoffs or somehow the iridium was damaged by improper (rough) gapping. They should come pre-gapped and should be gently "checked" to ensure the right gap, but regapping them can damage the tips.

EDIT: maybe others have thoughts about the wear. As far as which ones to go with, there are currently a couple of active threads going on right now that might help.

 

[Rocket Man]

Any reason I should go for AC Delco 41-162 or am I still ok with 41-110??

41-162 is the update for the 41-110 but either will work. In all honesty, I would get new ACDelco wires too. Anytime you’re pulling them on and off there’s a chance they separate inside the boot, where the metal clip starts to separate from the conductor. I use dielectric grease inside both ends of mine so they come off easier. As far as inspecting them, look inside the boots and see if there’s corrosion or if they look damaged although it’s hard to tell. Also inspect the wire itself for dark spots where they might have heat damage. On the inside the conductor isn’t like normal copper wire that regular wire has, it’s more like a carbon type of conductor and if a wire rests against an exhaust manifold (or header in my case) it might cause high internal resistance that doesn’t look like much on the outside.

 

[Rocket Man]

#8 plus is fairly easy if you put a 5/8” plug socket on, and use a standard depth 3/4” socket to turn the plug socket with, the plug socket will accept that socket. That’s the perfect length to put a ratchet on and turn it. I use a short extension in the plug socket by itself to get the plug started back in and hand tighten as far as possible, then switch back to the 3/4” socket to tighten it.

 

[Fless]

@Meccanoble, you're aware of this socket setup to make #8 relatively easy?
https://www.tahoeyukonforum.com/threads/8-spark-plug.111876/page-3

 

[Fless]

#8 plus is fairly easy if you put a 5/8” plug socket on, and use a standard depth 3/4” socket to turn the plug socket with, the plug socket will accept that socket. That’s the perfect length to put a ratchet on and turn it. I use a short extension in the plug socket by itself to get the plug started back in and hand tighten as far as possible, then switch back to the 3/4” socket to tighten it.

Get outta my mind!

 

[Rocket Man]

I just took a pic of what I was talking about but @Fless beat me to it!