Strange looking plugs
Thread Starter
Instructor
Joined: Jul 2004
Posts: 210
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From: Lakewood CO
Strange looking plugs
I have a '69 427 with a 3x2 setup. The timing is 14 degress with 38 total. It's been sluggish on take off so I pulled all the plugs to take a look. A couple were carbon fouled and others were light grey. I cleaned all the plugs up and reinstalled. I went for a 30 mile drive and started to experience the sluggish take off about halfway through the trip after idling at stoplights. I pulled the plugs when I got home and found this.
1-light brown
2-carbon fouled
3-oil&carbon fouled
4-carbon fouled
5-light brown
6-light brown
7-light grey
8-almost white
I've only had the car a couple of months and had a heck of a time getting it to pass emissions. I know the carb is running rich because the jetting is set up sea level and I live at about 6000' of elevation. I haven't gotten around to rejetting the carbs yet.
My question is this, does it seem like I have a major problem with the engine? I know that oil fouling is due to worn rings or blowby from the valve guides. I haven't done a compression test yet but I will this weekend.
Any thoughts or suggestions would be appreciated.
Thanks,
Dave
1-light brown
2-carbon fouled
3-oil&carbon fouled
4-carbon fouled
5-light brown
6-light brown
7-light grey
8-almost white
I've only had the car a couple of months and had a heck of a time getting it to pass emissions. I know the carb is running rich because the jetting is set up sea level and I live at about 6000' of elevation. I haven't gotten around to rejetting the carbs yet.
My question is this, does it seem like I have a major problem with the engine? I know that oil fouling is due to worn rings or blowby from the valve guides. I haven't done a compression test yet but I will this weekend.
Any thoughts or suggestions would be appreciated.
Thanks,
Dave
Pro
Joined: Dec 2002
Posts: 560
Likes: 1
From: Mooresville NC
Definitely do a compression test and cmpare the reading to the spark plugs. I would expect lower readings on 2,3,4, & 8, they look suspicious to internal engine problems. 8 - could be coolant being burned up in the cumbustion chamber (ie possible head gasket problems). How many miles on the engine?
Rejetting may cure 2, 3, 4, but carb rebuilding may be the better intial start if it has many miles on it.
Have a fun weekend.
Rejetting may cure 2, 3, 4, but carb rebuilding may be the better intial start if it has many miles on it.
Have a fun weekend.
Thread Starter
Instructor
Joined: Jul 2004
Posts: 210
Likes: 0
From: Lakewood CO
History of the car is sketchy at best so I don't know much. I was told that the engine was rebuilt about 10k miles ago but I have my doubts. I know it sat for most of the past 2 years before I bought it. It only was driven 1900 miles since the previous owner titled the car. It's showing just over 51k right now for what it's worth.
I've put about 900 miles on it the past 2 months and it seems to be getting worse. I was hoping to put off the rebuild until the winter. Bummer.
I'll get the compression tests done this weekend.
Thanks for the help.
Dave
I've put about 900 miles on it the past 2 months and it seems to be getting worse. I was hoping to put off the rebuild until the winter. Bummer.
I'll get the compression tests done this weekend.
Thanks for the help.
Dave
Last edited by L71Maynard; Sep 10, 2004 at 05:25 PM.
