Giles' Mystery High RPM High KR

gv_racing

gv_racing

Greenie N00B Member
Hey all, long time lurker first time poster. I pride myself in being a pretty good automotive troubleshooter, but this issue has been absolutely kicking my ass on my fresh engine and setup. I need the help of the MPS hive mind.

ENGINE/DRIVEABILITY

Year/Make/Model: 2010 USDM Speed3
Mileage: 210k kms body/trans 1800kms engine
Location: PEI Canada
Concern: 3+ KR after approximately 5800RPM
DTC's: Nothing interesting. P0401 P0421 P2006 P2009 (No EGR, no VCTS, catless)
Modifications:
Built engine with stock valvetrain. 88mm Mahle 4032 pistons, Manley H-Tuff rods. Machining done by Arsenault Cylinder Heads in NB Canada, and assembled by yours truly (there's the issue right there)
CST4 IWG
CS EBCS
Damond 3.5 TIP
Damond Focus ST Mani adapter, non PI
Damond BSD
Damond "stage 1" catch can with the VTA check valve + breather
Damond street RMM
Damond EGR delete
Stock side mounts (sus)
Corksport TB
Corksport TB Spacer
AEM methanol kit shooting into the TB spacer (not active in this stage of the tuning)
Treadstone TR8 core and custom piping
ACT ZX5-HDSS clutch kit
Autotech HPFP bits
VS Racing x50 BOV (tial clone) with a 12psi spring
Serviced fuel injectors + new Overspeed seals purchased from Chris Ward Turbochargers with only 1600kms on them at this point (I pray that these are not the problem, I did everything right boys )

ECU/Tuning Software: Stock/ Accessport v3
Tuner: Will Dawson @ PD
Is the concern intermittent? Nope
Can you duplicate the concern? Yes, every time
Recent Repairs/Troubleshooting Steps:
- Secured the knock sensor wire REALLY well (the sensor is torqued to 15 ft lbs)
- Tried another set of brand new NGK 6510 plugs gapped by me to 24 thou
- Tried two different sets of OEM coil packs off of my parts cars
- Tried tweaking/ re springing the terminals inside the injector connectors to ensure a good connection
- Checked the visual cleanliness/ resistance readings of the five engine bay ground locations I know of
- Checked the resistance between the connector and each injector connector terminal searching for internal breakages
- Cleaned mystery dark fluid out of the inside of injector connector #4 (wtf? it is positively not wicking up the harness, is it leaking out of the injector? I will be monitoring this as I continue to drive the car)
- Did the same for the coil pack connectors
- Completely drained the tank and filled up with 91 from a different gas station
- Did a hot compression test, 186/186/192/190
- Boost leak test, putting 20psi in the system takes 65 seconds to reach 10psi, I think that's a good result?
- Cleaned my OEM maf sensor with maf cleaner
- Got pissed off about it, somehow no improvement

I am on my first revision from Will trying to run 21psi on 91 octane. The car pulls nice and hard until ~5800rpm and even after that, you wouldn't always know there was an issue until you look at the KR. Sometimes the pulled timing is felt, sometimes not as much. At this point I do not know if it is genuine predetonation or the sensor picking up noise. I do not have access to E85 to see if it goes away. I am including four data logs. 12 is when the issue was first discovered, 22 and 23 are after I tried new coils and plugs, and 36 is after attempting everything mentioned above just the other day. 36 appears to be a mild improvement but it may have been a fluke or related to hot weather, but still not where I'd like to see the readings.

Also worth mentioning is that I am running a f#@ked up stock PMM that has lost all its fluid. I just lubed up and ordered the Damond side mount combo set as I already have their RMM. Could be the source of the readings, but I doubt it. We will see.

Thanks gang
 

Attachments

Couple of things:
1. If there is a race track somewhere nearby, you can probably get 3 gallons of E85 racing fuel from them (it will be expensive but worth it for peace of mind)
2. Does the issue happen regardless of engine load? Happening at the same RPM range ish every time seems like a resonance issue to me; like maybe a cover or some other small piece of metal isn't fully tightened down to the engine or is barely touching maybe.
3. Though it would be strange, I wouldn't count out the PMM.
 
Enki said:
Couple of things:
1. If there is a race track somewhere nearby, you can probably get 3 gallons of E85 racing fuel from them (it will be expensive but worth it for peace of mind)
2. Does the issue happen regardless of engine load? Happening at the same RPM range ish every time seems like a resonance issue to me; like maybe a cover or some other small piece of metal isn't fully tightened down to the engine or is barely touching maybe.
3. Though it would be strange, I wouldn't count out the PMM.
Click to expand...

Thanks for your thoughts. I actually made a note in my phone to try a pull at partial throttle to see if it's load or RPM related. Will probably give that a try this evening. Also may try holding the clutch pedal in slightly during the problematic area to see if it's related to my throwout bearing making a racket - it's pretty loud at idle once the car is warmed up. Just another theory to disprove.

My province sucks majorly for motorsports, the closest drag strip is 3 hours away. If I completely run out of ideas, I may order some boostane octane booster to bring the octane rating up a few numbers to get a better idea if it is true predetonation or not.
 
You can buy science grade ethanol on Amazon, but it's pricey ($30/gallon). One gallon at under half a tank would probably work to show some kind of change, but you'd need to swerve the car back and forth pretty hard to make sure it's mixed in well.
 
I have made some progress on this and figure I might as well share to the class. I ran out of hair to pull and started yanking my injectors out with the intention of swapping out #4, the one which appears to be leaking from inside the connector. Last time I blasted the connector and receptacle out with electronics cleaner, so I could see if it came back, and it did. Not a crazy amount, but there is almost definitely fluid originating from inside the injector connector. Then, I pulled injector 3.

Uhh,

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WTF are we looking at here? It's a microscopic piece of aluminum that was trapped underneath exactly where the injector seal needs to crush. Needless to say, we had an injector leak. Where did this aluminum chunk originate from? I truly do not know. Probably left there by the machine shop as it looks like a chip to me, and despite my efforts to clean the injector holes out with a drill + shop towel + brake clean apparatus, this managed to get left behind un noticed. Does make me wonder how much other un noticed metal debris could be in my engine, but given that it's got 2000 kms and 4 oil changes under its belt with great comp, I think we are okay.

I got very excited when I found this, as it's the first progress I've made on this KR issue in weeks, despite how stupid of an issue it is. I did not have new overspeed seals on hand, but I did have a used overspeed seal that had been used in this hole from its previous life. I threw it in #3 with the aluminum debris removed, left injector #4 as is for now to not change too many variables at once, and re assembled my fuel rail and intake manifold for the twentieth time.

Before:

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After:

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We're on the right track, baby. Still problematic, but a noticeable repeatable difference. So, next:

1. Install my damond side motor mounts when I receive them

2. Install a brand new seal in injector #3 (waiting on this too)

3. Maybe replace injector #4 due to the leaking connector... Want to be 110% certain it is actually doing this before I swap out an injector I just paid good money for.
 
Sigh. This is getting pretty depressing.

Damond motor mounts - no improvement

Swapping out injector 4 - no improvement

Brand new set of overspeed seals - no improvement

I honestly think my last update was a fluke. Sometimes it only registers between 2 and 3 degrees after a pull, but most of the time it is between 3 and 4 degrees. I don't think the behaviour has responded to any of the things I've tried.

At this point the only thing I can think of that makes any sense is to replace injectors 1, 2, 3. If that doesn't fix it, I truly do not know what I am going to do with the car. :(
 
Alcohol in the fuel tank would work to tell you if it's actual combustion KR or just engine noise (like a loose heat shield).

Edit: Injectors are expensive as fuck, I'd do a corn test first, tbh.
 
Enki said:
Alcohol in the fuel tank would work to tell you if it's actual combustion KR or just engine noise (like a loose heat shield).

Edit: Injectors are expensive as fuck, I'd do a corn test first, tbh.
Click to expand...

I have a second set of recently serviced injectors on hand, so no cost involved there. I was going to try swapping them in earlier, until I found my leaking injector #3 and decided to leave them alone as I was blaming the seals at the time. I have no access to E85, just the E10 that we have at our pumps now. Any advice for what to search for to find science grade ethanol on Amazon like you mentioned? Nothing is jumping out at me as being 100% ethanol https://www.amazon.ca/s?k=pure+ethanol
 
I would think most "denatured" products will use methanol for the required percentage needed to make it non-consumable, since it's relatively inexpensive and also blends well with ethanol. Anything "200 proof" or chemical grade is likely to be low water content, which is the main concern (as high water content will cause it to separate the alcohol from the gasoline, which is very, very bad). If you've ever used or seen a water-based ethanol % tester, that's basically what happens.
 
Jesus christ. It was one of the injectors. Check out this 4th gear 3k-7k WOT log, that is night and day. Repeated across a few pulls. Finally I can continue the process with Will @ PD. Yay.

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Not entirely sure how to feel right now. Elated that my car can get tuned now. Less than thrilled that I spent 300 bucks to trade my injectors for a serviced, flow tested set that's clearly not operating right. I'll see what Chris thinks.

I guess regardless it's good that in all of this I caught that piece of metal screwing up the seal on #3 ¯\_(?)_/¯
 
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It seems reasonable to me that anything gangster enough to build up at operating pressure is likely to need operating pressure to be cleaned out, unless you're running some SERIOUSLY nasty cleaning shit.
 
It's not over yet. Replacing the injectors did make a lasting difference, but as soon as I got my next revision from Will, things started getting dicey again. Then, he sent me a followup tune with a fuel taper, which I believe will slightly lean out the mixture towards redline. This should make the problem worse if it is due to fuel delivery (I think). It did.

The same tune I was troubleshooting with all along (38 deg BAT may have caused this to be slightly worse than the log I posted before, dunno)
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After Will tried to apply additional sauce
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After Will added the fuel taper towards redline
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With all that said, I am currently running

Injector 1, 3, 4 - Cleaned and flow tested in 2021 by toronto injectors, previously happily run in this car at 26psi, but was in the car whenever A. I blew the engine up last spring and B. was in the car whenever I used shitty injector O ring seals (the injector to fuel rail side) that disintegrated and possibly contaminated them (this is why I ordered the fresh set, did not trust them, and probably still should not, but I put them back in for science)
Injector 2 - My original injector 2 has its screen blown out and is visually crammed with green O ring bits, so could not be used. Used injector #4 from the CW set which I had previously swapped due to it leaking slowly out of the electrical connector. I swapped this one out previously, and there was no behavioral difference, so it is probably fine but I can only speculate.

TLDR my injectors are still not trustworthy. Going to pull the mani + fuel rail again (my favourite), and get the full CW set sent back for inspection/verification.
 
Is it possible to put a safer tune on it briefly, and do a few pulls just to see if knock happens?

Are you putting any e85 in there?

Nothing banging around the engine bay?

Good luck man.. I'm dealing with something similar
 
automaticonlyspeed3 said:
Is it possible to put a safer tune on it briefly, and do a few pulls just to see if knock happens?

Are you putting any e85 in there?

Nothing banging around the engine bay?

Good luck man.. I'm dealing with something similar
Click to expand...

Thanks for the luck, I think I'm gonna need it lol. At this point I am convinced it is genuine predetonation knock, versus engine bay noise. Everything is pretty meticulously wire/ hose managed, and the knock is non-existent at turbo spring pressure, acceptable on my first revision (1.5 max), and unacceptable on my second revision (2.5-3 max). Thinking it's gotta be a bad injector leaning out one or more cylinders.

After all this is over I'm gonna have the quickest injector swap speedrun in the game
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While I'm in here yapping, why tf do these two intake valves on the same cylinder (1) show such dramatically different carbon buildup? Every time I pull the mani, the left valve looks clean and the right valve looks wet and goopy. Valve stem seal? There's never any oil smoke/smell on startup

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