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Discussion Starter #1
Direction or assistance requested from the 302 engine gurus.

Problem: re-occuring problem of the #8 cylinder fouling spark plugs with large chunks of carbon, approximately 700 to 1200 miles. This has happened 3 times since September and it's the #8 cylinder each time.

Here's a list of the current equipment on the rig:

302 EFI w/ 122k on the clock
Aod (has been checked out by reputable tranny shop) no issues
K&N ghetto fab air filter
Ford Racing Headers with 40 series 3" exhaust, new O2 sensor
New 9mm Ford wires
New Dizzy gear
New Coil

List of current maintenance:

Seafoam treatment- 3 times thru vacuum system, 3 fuel tank treatments
Throttle Body, Plenum and Intake cleaning with new gaskets
New Plugs, gapped .045
New EGR valve
New PCV valve
Timing 10* BTDC
New Timing Chain
No codes
3 oil changes with filter
Current compression in cylinders#1 through #7 avg. 126 psi. #8, 111 psi.

FSB search:
Other than the "seafoam" tech write up
keywords- "carbon", "plug fouling" yielded no tangible info.


Your suggestions and search re-direction will be rewarded with free holiday cheer, tomorrow of course.
 

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aka: kemicalburns
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the pcv needs moved to the center of the upper intake. this would be my guess
 

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valve seal, or ring going?
 

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Discussion Starter #4
Thanks for the replies to this point.

Would the symptom of a fuel injector that leaks overnite, i.e. non engine running, be possible?

Haven't had any starting or rough idle issues. No excess smoking on cold start nor warm start.
 

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Discussion Starter #6
Paralyze-

Hard to tell if there was a direct link with seafoam treatment. This all started back in September to address engine "pinging" and excessive vibration when
driving the rig in Overdrive. Most all the engine related "mods" were accomplished within a month's time with very little highway driving. After heavy cleaning of the TB, Plenum and intake I personally thought all this engine debris or carbon would have quietly gone away. Taking mileage into consideration, a valve job or new heads may be around the corner.
 

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I would also suggest moving the PCV to the center of the manifold as kemicalburns said. Have you given it a good run since the Seafoaming? The Seafoam could have loosened stuff up. A good freeway tune up might help to. Another idea is to try a sparkplug 1 heat range hotter in cylinder#8
 

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Discussion Starter #8
Any tips on relocating the pcv valve to the center? Maybe a creative way to accomplish this job.....
 

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Move the PVC, keep running Seafoam every 5-7K and TOW SOMETHING! Every time either my Silverado, Bronco, or Cummins gets sluggish, I tow something (usually 2 cars with the Cummins!) Seems to clean things right out.
 

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Discussion Starter #10
Looks like a road trip. A couple of Jimmy Buffet cd's and thermos of egg-nogg and here we go. I might take a couple of ounces (of seafoam) and squirt in the number 8 hole and let it soak overnight. Take it easy for 25 miles then get on the skinny pedal for awhile.
 
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