my 1984 4.9l f150 won't start. clueless
#1
my 1984 4.9l f150 won't start. clueless
so im going run done the things i know are working for sure, battery reading 12.5 volts, strong spark in all 6 cylinders from the plugs to wires, coil, rotor is rotating, carb is spraying fuel, clean filters and fuel,spark plugs are fairly new module is good so are all my connections terminals, other wiring etc etc. and it has a strong crank and engine is rotating good but not starting after i parked it for only 2 weeks and was running perfect before. although the choke valve won't open while cranking, i can move with my finger easily. now i ziptied it open and i hear it "farting" out the exhaust like if it wants to start but doesnt. if i dont ziptie it it will just crank only. timing is good. its a real head scratcher because it has all elements for it to run but doesn't. plus i did some head work a year ago so everything in the top half of engine is legit
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#8
If you are getting spark to the plugs and fuel to the carb & plugs (you did say plugs were dry?).
I would check if the rotor is pointing to where it needs to like #1 cly like was posted.
I would also do a quick compression check just because you there.
I would also install a new set of plugs. I say this because I had a car that had newish plug in it. It sat for months on end till I needed to move it, read not much run time on the newish plugs.
Anyway went to move it one day and any time I gave it gas it would back fire out the tail pipe.
After a compression test to make sure a valve was not hanging open and finding what cly was the cause I moved the plugs to different cly and the back fire followed.
After changing plugs all was fine again. I would never believe it if I did not see it my self.
Dave ----
I would check if the rotor is pointing to where it needs to like #1 cly like was posted.
I would also do a quick compression check just because you there.
I would also install a new set of plugs. I say this because I had a car that had newish plug in it. It sat for months on end till I needed to move it, read not much run time on the newish plugs.
Anyway went to move it one day and any time I gave it gas it would back fire out the tail pipe.
After a compression test to make sure a valve was not hanging open and finding what cly was the cause I moved the plugs to different cly and the back fire followed.
After changing plugs all was fine again. I would never believe it if I did not see it my self.
Dave ----
#9
Welcome to the forum!
From your original post, "although the choke valve won't open while cranking, i can move with my finger easily".
The 1984, if still original, is equipped with a choke pull-off device, which is vacuum controlled. There is a small vacuum hose which connects between the pull-off solenoid and a vacuum port located on the bottom of the carburetor [driver's side]. The choke plate, which is adjusted to be completely closed when cold and not running, is slightly opened as soon as the engine starts revolving, even while starting.
If this is not working [check the hose and connections], the engine cannot get air to start. When you zip tied the choke open, the mixture will be too lean to start, unless you really pump the gas pedal rapidly.
From your original post, "although the choke valve won't open while cranking, i can move with my finger easily".
The 1984, if still original, is equipped with a choke pull-off device, which is vacuum controlled. There is a small vacuum hose which connects between the pull-off solenoid and a vacuum port located on the bottom of the carburetor [driver's side]. The choke plate, which is adjusted to be completely closed when cold and not running, is slightly opened as soon as the engine starts revolving, even while starting.
If this is not working [check the hose and connections], the engine cannot get air to start. When you zip tied the choke open, the mixture will be too lean to start, unless you really pump the gas pedal rapidly.
#10
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