One Cylinder Running Richer?
- vwlover77
- IAC Addict!
- Location: North Canton, Ohio
- Status: Offline
One Cylinder Running Richer?
While examining my spark plugs, I found something curious.
The electrodes on all four plugs appear the same - a flat, light gray color. The center insulators are all still basically clean. (The plugs have only a few thousand miles on them.)
Cylinders 1, 2, and 4 have a very minimal light coating of carbon on the bottom of the threaded base of the plug.
But, #3 has a much heavier dark fluffy coat of carbon on the bottom of the base.
Would this indicate the #3 is running richer than the other cylinders for some reason?
I had my fuel injectors cleaned and tested by Cruizin' Performance a couple of years ago and they all were very equally matched.
I'm considering swapping the injectors for #3 and #4 to see if the additional carbon buildup moves with the injector.
Any other suggestions? I don't see how the air intake to #3 could be restricted.
The electrodes on all four plugs appear the same - a flat, light gray color. The center insulators are all still basically clean. (The plugs have only a few thousand miles on them.)
Cylinders 1, 2, and 4 have a very minimal light coating of carbon on the bottom of the threaded base of the plug.
But, #3 has a much heavier dark fluffy coat of carbon on the bottom of the base.
Would this indicate the #3 is running richer than the other cylinders for some reason?
I had my fuel injectors cleaned and tested by Cruizin' Performance a couple of years ago and they all were very equally matched.
I'm considering swapping the injectors for #3 and #4 to see if the additional carbon buildup moves with the injector.
Any other suggestions? I don't see how the air intake to #3 could be restricted.
Don
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78 Westy
71 Super Beetle Convertible Autostick
"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen
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78 Westy
71 Super Beetle Convertible Autostick
"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen
-
- IAC Addict!
- Status: Offline
Doesn't really matter whats on the end of the threads. What matters is the condition of the electrodes and the insulator. The bit of fluff may be due to different depth of spark plug holes aloowing a wee bit more of the threads being exposed in th chamber, or the plug gap is facing a direction that is not optimum for ignition. Google indexing spark plugs.
JMHO not necessarily gospel.
JMHO not necessarily gospel.
1/20/2013 end of an error
never owned a gun. have fired a few.
never owned a gun. have fired a few.
- vwlover77
- IAC Addict!
- Location: North Canton, Ohio
- Status: Offline
Very interesting! I had never heard of plug indexing before. I'll have to give that a try!
For the moment, I'm just driving and enjoying it!
For the moment, I'm just driving and enjoying it!
Don
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78 Westy
71 Super Beetle Convertible Autostick
"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen
---------------------------
78 Westy
71 Super Beetle Convertible Autostick
"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen
- IFBwax
- IAC Addict!
- Location: PDX
- Status: Offline
As Gypsie asked about CHT, I'm wondering if you have the CHT sensor on #3 and if that could be a factor.
The best navigators aren't sure where they're going until they get there. And then they're still not sure.
Frank Bama
http://www.partypickle.blogspot.com
Frank Bama
http://www.partypickle.blogspot.com
- vwlover77
- IAC Addict!
- Location: North Canton, Ohio
- Status: Offline
Ah, sorry, I forgot I had not responded about that. I do need to run a compression check, and I do not have a CHT gauge or sensor - and don't want one!!!
Don
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78 Westy
71 Super Beetle Convertible Autostick
"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen
---------------------------
78 Westy
71 Super Beetle Convertible Autostick
"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen
- Amskeptic
- IAC "Help Desk"
- Status: Offline
If your engine is running smoothly with a steady idle and decent pick up, the chances of different mixture in one cylinder is much less likely than a set of rings giving you more oil (we're not talking "wet plug" just a little vapor) that promotes carbon build-up. As noted, the color of the electrode ceramic is the key determination of mixture. The periphery of the plug gives you more of a snapshot of conditions in the cylinder, compression and oil rings, cylinder cooling, exhaust manifold leaks, etc.vwlover77 wrote:Ah, sorry, I forgot I had not responded about that. I do need to run a compression check, and I do not have a CHT gauge or sensor - and don't want one!!!
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles