Finally found my misfire

MEATSWORD said:

You are right there catch can might be worth thinking about
Good luck

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pfram said:

After a year of an annoying misfire on cylinder 6 I finally got around to using my cheapo mdi2 clone and did an injector balance test and it confirmed a well below average pressure drop so decided to take action and take off the s/c and took to see what's up. Pretty easy to see something has been leaking there. Pulled rail out and sure enough junk getting past injector seal and bunch of crud in the seal.

Figured I'd replace the one injector, but apparently I couldn't find the exact number anywhere and found out that there are like 15 different parts numbers for same injector and that functionally is the same but numbers must match as there are low flow, nominal flow, and hi flow which I don't understand at all since again functionally are exactly he same. So not wanting to go through this process again, I said screw it and just bought 8 new injectors from good ol rock auto for just $420. Which is significantly cheaper than anywhere I could find. Plus it gave me an excuse to light up because well 420, lol.

So I guess wanted to pass that info along if it helps anyone. Also apparently the pipes that connect to the rails and hi flow pump are one time use so that was annoying but is what it is. I'm sure I could have reused, but why take the chance?

You can see how much dirtier cyl 6 is in pics View attachment 167168 View attachment 167169

Sent from my Pixel 7 Pro using Tapatalk

Click to expand...

pfram said:

After a year of an annoying misfire on cylinder 6 I finally got around to using my cheapo mdi2 clone and did an injector balance test and it confirmed a well below average pressure drop so decided to take action and take off the s/c and took to see what's up. Pretty easy to see something has been leaking there. Pulled rail out and sure enough junk getting past injector seal and bunch of crud in the seal.

Figured I'd replace the one injector, but apparently I couldn't find the exact number anywhere and found out that there are like 15 different parts numbers for same injector and that functionally is the same but numbers must match as there are low flow, nominal flow, and hi flow which I don't understand at all since again functionally are exactly he same. So not wanting to go through this process again, I said screw it and just bought 8 new injectors from good ol rock auto for just $420. Which is significantly cheaper than anywhere I could find. Plus it gave me an excuse to light up because well 420, lol.

So I guess wanted to pass that info along if it helps anyone. Also apparently the pipes that connect to the rails and hi flow pump are one time use so that was annoying but is what it is. I'm sure I could have reused, but why take the chance?

You can see how much dirtier cyl 6 is in pics View attachment 167168 View attachment 167169

Sent from my Pixel 7 Pro using Tapatalk

Click to expand...

pfram said:

Yeah Ive considered for sure, but I really haven't seen an issue with the stock version to do the upgrade. I'm sure a true catch can would do a better job though. My issue was simply a bad injector seal. Looking at the intake valves while sc is off they aren't very dirty at 40k miles. Just a ring of crud about halfway up the stem, but the tops of the valves themselves are surprisingly clean. That said I have run a can of top engine cleaner about 10k miles ago so I'm sure that helped some.

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