Please read my plugs
#1
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Please read my plugs
Took them out yesterday after about 2000 boosted miles @ 7-9 psi. They are Autolite 3923's which cross-reference with NGK BKR6. Running at stock gap (0.8 mm), no misfires etc.
Pl help me understand whats going on in #4?? They don't seem to be aluminum deposits but I could be wrong. The electrodes arent melted either, it just seems to be some other crud that's on there.
Pic 1: L to R: #1 thru #4
Pic 2: close up of #4
Pl help me understand whats going on in #4?? They don't seem to be aluminum deposits but I could be wrong. The electrodes arent melted either, it just seems to be some other crud that's on there.
Pic 1: L to R: #1 thru #4
Pic 2: close up of #4
#5
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I know they're hotter than required, I'm only concerned about the deposits on #4. There is no reason for those deposits to be there in any rpm range.
LOLA, finding NGK's here is close to impossible. I can throw on some 3922's (one colder range) though.
LOLA, finding NGK's here is close to impossible. I can throw on some 3922's (one colder range) though.
#7
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and second, why do you need to read plugs? modern cars have many ways to gather the same information (o2 sensor, knock sensor, egt)
#9
I'll take a guess... it's a combo of ash deposits and oil fouling.
"APPEARANCE: Ash deposits are characterized by light brown or white colored deposits crusted on the side or center electrodes. In some cases it may give the plug a rusty appearance.
CAUSE: Ash deposits are normally derived from oil or fuel additives burned during normal combustion. Normally they are harmless, though excessive amounts can cause misfiring. If deposits are excessive in short mileage, the valve guides may be worn."
http://www.classictruckshop.com/club...park/plugs.htm
"APPEARANCE: Ash deposits are characterized by light brown or white colored deposits crusted on the side or center electrodes. In some cases it may give the plug a rusty appearance.
CAUSE: Ash deposits are normally derived from oil or fuel additives burned during normal combustion. Normally they are harmless, though excessive amounts can cause misfiring. If deposits are excessive in short mileage, the valve guides may be worn."
http://www.classictruckshop.com/club...park/plugs.htm
#11
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not really. just a whole lot of soot.
I haven't used any additives at all to cause the , only straight 93 octane since I was turbo'ed.
the plug has no reason to look like that on an engine running normally, regardless of rpm.
and, plugs never lie, O2 sensors can lie specially if the engine's been burning oil.
I haven't used any additives at all to cause the , only straight 93 octane since I was turbo'ed.
and, plugs never lie, O2 sensors can lie specially if the engine's been burning oil.
#13
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Am I seeing things or is that #4 electrode cracked? I am looking at the light colored portion at about 7 o'clock in the second image.
The rest of the plugs look lean to me.
+1 on getting a WBO2 sensor as a tuning tool.
The rest of the plugs look lean to me.
+1 on getting a WBO2 sensor as a tuning tool.
#15
The other three plugs do look a bit lean. If one injector is stuck open (making the plug sooty), and the ECU is running closed loop off of an O2 sensor, the ECU might see that as a reason to cut injector duration, making the rest of the cylinders run lean. Not knowing whether MSI Ver.3 works that way kind of makes this answer a crap shoot, but it's all I got.
#16
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The other three plugs do look a bit lean. If one injector is stuck open (making the plug sooty), and the ECU is running closed loop off of an O2 sensor, the ECU might see that as a reason to cut injector duration, making the rest of the cylinders run lean. Not knowing whether MSI Ver.3 works that way kind of makes this answer a crap shoot, but it's all I got.
But yeah, what you say might be a possibility, specially since my injectors are straight off the junkyard, not blueprinted.
#17
And besides; the deposits you see may not be happening under boost but at manifold pressures where you normally drive and where you're running closed loop. Under those circumstances a stuck injector is more likely to give you the symptoms you're seeing.
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