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673 mack injector pump timing


jhcattle
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I dont know what your saying when you say setting the front plate up.First thing you need to be on # 1 cylinder and you can only know that when you pull a valve cover. The valves will be on over lap on # 6 when 1 is ready to set.I pull the delevery valve spring out of # 1 delevery valve and then with pressure on the pump as you turn pump the fuel should shut off at port closure which is starting of injection on # 1. Also mash you throdle down and make sure your stop in in go fast mode.

glenn akers

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I'm determining i'm on the 1st cylinder by setting when both #1 valves are up. This may not be right. What Im calling the front plate is the round disc with the 4 slotted holes under the round cover on the timing cover. I loosened the 4 bolts rotated the shaft down and let fuel flow through the 1st plunger with the valve and spring out and was looking for the fuel to stop flowing as i rotated the shaft up, but the fuel doesnt stop flowing.

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I'm determining i'm on the 1st cylinder by setting when both #1 valves are up. This may not be right. What Im calling the front plate is the round disc with the 4 slotted holes under the round cover on the timing cover. I loosened the 4 bolts rotated the shaft down and let fuel flow through the 1st plunger with the valve and spring out and was looking for the fuel to stop flowing as i rotated the shaft up, but the fuel doesnt stop flowing.

Then your stop is pulled out. mash your throdle to the floor when timing it.

glenn akers

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If you took the delivery valve out you need to snug the nut back down did you do this?If you are still having greif post a picture of the pump it my help us determine what your up against.I use a hose and blow thru it to time most of the time!

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Are you sure your on # 1 cyl?And another thing if you have had the pump off you could have it one turn off if the tang or pointed pin is broken off of the pump drive coupler.If the pin is still on the coupler then you have to been in time with the engine so it sounds as if your on # 6.When you are at TDC with 1 and 6 the valves will be up on both cyl but they have just over lapped on # 6 when coming to TDC when rotating the engine.The over lap means the intake exhaust valve just closes and then the intake starts to open and that is over lap, so its opposing cyl up will be ready to set valves or to fire.This is at TDC but your timing it 29 degress before you get there.I have seen barrels and plungers worn out enough that they will never stop flowing but will slow down to just a small dribby.

glenn akers

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number one is toward the front of the motor on the pump and the motor. the intake has just closed on one and we roll the motor on around to 29degrees and both are closed on one. the fuel flow doesnt seem to change when adjusting the pump. we have the valve and spring out and threaded the nut back in, filled the fuel filter with fuel and opened the fuel shut off valve. fuel bubbles up out of the fuel line hole about 1/4 inch and doesnt seem to change when we adjust the shaft clockwise slowly

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