My 68 c10 won't start, it backfires through the carb.. It turns but just won't fire up.. Could it just be the timing is off or it may need new plugs? It's a Holley carb. Or does it need a tune up?
Plugs, points, condenser, cap, rotor, plug wires, fuel and air filter makes a good tune up, but be careful with the backfire through the carb, as it is a holley you could blow out the power valve if it hasn't been upgraded.
Think the timing could just be off though?
Yes it could, but you need to make sure the dwell is correct as that will change timing also, as it is popping back through the carb try advancing it a little bit as see what happens.
More that not it is the timing. Several things can change the timing. You may have bad points or they could be lose, your timing belt may have become lose and slipped the timing, in that case you must be careful it does not hit the valves and pistons, or it may be a cracked distributor cap causing a cross fire in the cap to a wrong wire. Start with the cap first. Next check the points, then if nothing elce, try to find top dead center on cylinder # 1 and see where the rotor is positioned. This may have to be done by an experienced mechanic. Don't start the C10 until you are sure the timing is correct and the belt is not lose or broken.
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