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Questions and Answers

Ford F-150 Timing

Q. I have an 1986 F-150 that has 121,000 miles on it. It has a carburetor. It is automatic and has a 300 6-cylinder engine. My problem is that it lacks power when I step on the gas. I know that a six cylinder is not a speedster, but it takes it's sweet time moving when I step on the gas. It also uses a lot of gas, I think, for a six cylinder.

It gets right at 12 miles to a gallon. I have replaced the rotor, spark plugs, wires, new carburetor, MAP sensor, air filter, PCV valve. I have replaced the plastic vacuum lines with rubber hoses, and I am pretty sure I traced them back to the right place. What is different, is that someone put, evidently a 1984 distributor in it because when I went to change the rotor, they gave me a straight rotor and it needed a round one. Also, according to the Haynes repair manual, to put it in time, the six cylinder is supposed to have a notch in the flywheel, which mine does. (a notch about a quarter inch long cut into the flywheel) I try to use this and I can't get the timing light to line up at 10 degrees below 0, So I just put it in time where it would run the best and start the best. If you can't give me a suggestion, I guess the next thing for me to do is to put it on one of those diagnostic computers. I hate to spend more money, but the parts I have already put into it should have taken care of the power lose and the gas mileage.

Any suggestions?

A. What happened here is whoever put the distributor in, put it in a tooth off. What you will need to do is set up the base timing and then make the final adjustment with your timing light.

To do this you will need to remove the valve cover, distributor cap and number one spark plug. By hand, rotate the engine until the timing mark on the pulley is lined up with the zero mark on the timing plate. Look at the valves for number one, they should be completely closed and the piston should be at TDC. If this is correct, then the engine is at TDC on the compression stroke. If the valves are starting to open, you are on the exhaust stroke and need to go one more turn on the crankshaft.

Now the rotor should be pointing at the number one spark plug tower of the distributor cap. If it isn't, take note of which way it has to go to move it into the proper position. Now you will need to take out the distributor hold down bolt and slowly lift up the distributor. This takes a certain amount of "feel" to do this since you can't see the gears. The rotor will rotate as you lift it, you want to lift it just enough to clear the gear. Now feeling the gear, turn it one tooth in the direction it needs to go and slide the distributor back into position. Make sure the rotor points in the proper place.

Be careful and be sensitive to the feel of the gears. You want to slide up the tooth of the gear, run across the top of it and down the other side in the direction you need to go. Once you have done this, button everything up and you will be able to fine tune the timing with your light.

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