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Joined: Mar 2005
Posts: 10
Grease Monkey
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Grease Monkey
Joined: Mar 2005
Posts: 10 |
Any suggestions (short of pulling heads) to remedy carbon build up ? Is there a product additive anyone can recommend to try frist ? Timing is set to specs. just wants to keep on dieseling when key is "off". Jon
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Joined: Nov 2001
Posts: 29,863
Tech Advisor ChatMaster - 25,000
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Tech Advisor ChatMaster - 25,000
Joined: Nov 2001
Posts: 29,863 |
Need more to the story! What year car, what engine, what carburetor, does your car have an anti-diesel solenoid and etc.?
:confused: :confused:
The Mangy Old Mutt
"If It's Not Junk.....It's Not Treasure!"
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Joined: Mar 2005
Posts: 10
Grease Monkey
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Grease Monkey
Joined: Mar 2005
Posts: 10 |
Not my 61 chev. , it's my 51 MG TD. No bells or whistles on this one! 1250cc 4 banger, SU carbs (2), no solenoid
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Joined: Feb 2002
Posts: 1,178
ChatMaster - 1,000
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ChatMaster - 1,000
Joined: Feb 2002
Posts: 1,178 |
I would look closely at the timing.
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Joined: Sep 2004
Posts: 382
Backyard Mechanic
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Backyard Mechanic
Joined: Sep 2004
Posts: 382 |
Give it a tank of premium fuel occasionally until you can pull the head.
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Joined: Dec 2001
Posts: 11,162
ChatMaster - 10,000
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ChatMaster - 10,000
Joined: Dec 2001
Posts: 11,162 |
leave it in gear and pop the clutch as you turn the key off!
Life's a long winding trail, love Jesus and ride a good horse!
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Joined: Nov 2001
Posts: 19,758 Likes: 63
ChatMaster - 15,000
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ChatMaster - 15,000
Joined: Nov 2001
Posts: 19,758 Likes: 63 |
GM has a can of carbon cleaner and there are other brands also. If I remember correctly, you set the engine to a fast idle pour in 1/2 the contents fast enough to stall the engine. Let it sit for a time then start and slowly pour the remaining contents while at a fast idle. I produces large volume of white smoke from the tailpipe and supposedly removes carbon deposits. Used it a couple of times with mixed results. Think it helped some in both cases but one was definately much better.
How Sweet the roar of a Chevy four!
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Joined: Sep 2004
Posts: 382
Backyard Mechanic
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Backyard Mechanic
Joined: Sep 2004
Posts: 382 |
Get on the interstate and run it at 5200 RPM (max rated HP) for about five miles, S/B between 75 and 80 with your 5.125 to 1 rear end.
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Joined: Sep 2006
Posts: 731
Oil Can Mechanic
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Oil Can Mechanic
Joined: Sep 2006
Posts: 731 |
Raising the octane of the fuel a little or slow the idle speed some. As little as 50 rpm can make a difference. I've read for years change the timing but how could that be? With the ignition off the plugs aren't firing! Retarding the timing does slow idle speed but idle speed should be adjusted after base timing is set. How many remember the early 70's? This was a major headache.
Chevrolet
Valve In Head, Ahead In Value
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Joined: Feb 2002
Posts: 1,178
ChatMaster - 1,000
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ChatMaster - 1,000
Joined: Feb 2002
Posts: 1,178 |
If the car is out of time, then there could be carbon build up as a result and thus sparks in the combustion chamber. Slowing the idle would help. I owned a Jeepster with the Buick V-6 in it, had the same problem and addressed it by slowing idle and making sure timing was spot on.
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