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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: three8six on January 06, 2011, 04:28:03 pm
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My truck is a 1986 c10 4.3 v6 quadrajet carb TH400 transmission shorty headers single 2 1/2 inch exhaust turbo muffler. Problem is my truck bogs out either too lean or too rich or something whenever you press the gas for any sort of mild acceleration. It just dies out, Ive replaced distributor, plugs twice, wires twice. Set timing to 0. It runs fine idling very smooth, even can rev it up and it doesnt really bog down its more when its under load. If anybody knows where I can find a wiring diagram for this engine also would be helpful? I did find a vacuum leak today fixed it, problem still wasnt corrected. I was curious if anybody has any more suggestions before I take this to a shop or burn it down in my yard?
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Have you replaced the fuel filter yet? If not try that, it can cause it to bog down.
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What about your vacuum advance? Maybe that?
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New carb, is there a fuel filter somewhere else other than that? Half full tank....and my vacuum is right about 20-21 at idle. Please dont be too rough on me...
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Also wanted to note is it "new" gas.
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does it overheat at all? How old is the exhaust/muffler, any cat converter? exhaust could be clogged w/ carbon and soote/rust. Mine had that problem. Too much back pressure.
Check for more vacuum leaks w/ some WD40, sounds like that too.
Choke working right? Opens up all the way after 2 or 3 minutes idling?
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Exhaust is all new. Headers are prolly a year old. The rest about a month old. No Cat converter, just a thrush welded muffler only about a month old. Id like to also say that none of this stuff has any miles on it maybe 2-3 miles tops?
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And no, no overheating. I did see my knock sensor isn't hooked up could this be an issue?
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Yes. If you have ESC it can do crazy things to your ignition timing without the knock sensor hooked up.
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ESC? you mean the electronically controlled carb?
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Electronic Spark Control. When the knock sensor detects pinging the ESC controller retards the timing. Hook up the sensor and see it that helps. Down the road though I would consider relocating the ESC system to the nearest garbage can.