I had not thought of those, I will check them ASAP.
Strange F-150 problem
- Thread starter Sous
- Start date
I had not thought of those, I will check them ASAP.
StromBusa
Registered
Good luck, them 300 6's in F150's were a nice set-up for trouble free pick em ups... I had 3 of them & the only issue I remember having was throttle bodies getting loose, so it sucked air underneath. Had to tighten them from the bottom up.... that & hydraulic clutch issues in the standards.
Just described the problem to a shade tree mechanic friend at work and he thinks it is the crank shaft sensor as well. I will look into replacing this part and update when that is done. Of course, the problem has only occurred 2 times in the past year, so it may be 2014 before I post back.
xchief1320
Registered
That truck doesn't have a external crank sensor. It does have a pickup coil (hall effect) sensor in the TFI distributor.
The truck turns over but will not fire up correct? First thing I would check is if it has spark and fuel pressure when it's acting up. Most important thing is to make sure it has fuel and it has fire. If it's missing one then you can diagnose it out from there.
Does the truck run good when it does run?
If it has dual tanks the selector switch in the dash can be the issue as well. I've replaced a few over the years. If you have no fuel pump when you turn the key to run this is something you can test. Sometimes you can flip the switch from the front to back tank a few times and then the truck will then cycle the pump when the key is turned on.
TFI modules do fail but 99% of the time they do it when the truck is hot.
The pickup inside the distributor can go out as well. If you pull the distributor cap can you wobble the distributor shaft side to side? The bushings in the distributor will wear and cause the exciter ring inside the distributor to hit the pickup coil (hall effect) sensor and that will cause issues. If this is the case and the truck has a ton of miles I would replace the entire distributor and not just the pickup coil (hall effect)sensor.
It can be alot of things. Easy to diagnose in person but almost impossible online... Test things before throwing money at it.
Good luck
The truck turns over but will not fire up correct? First thing I would check is if it has spark and fuel pressure when it's acting up. Most important thing is to make sure it has fuel and it has fire. If it's missing one then you can diagnose it out from there.
Does the truck run good when it does run?
If it has dual tanks the selector switch in the dash can be the issue as well. I've replaced a few over the years. If you have no fuel pump when you turn the key to run this is something you can test. Sometimes you can flip the switch from the front to back tank a few times and then the truck will then cycle the pump when the key is turned on.
TFI modules do fail but 99% of the time they do it when the truck is hot.
The pickup inside the distributor can go out as well. If you pull the distributor cap can you wobble the distributor shaft side to side? The bushings in the distributor will wear and cause the exciter ring inside the distributor to hit the pickup coil (hall effect) sensor and that will cause issues. If this is the case and the truck has a ton of miles I would replace the entire distributor and not just the pickup coil (hall effect)sensor.
It can be alot of things. Easy to diagnose in person but almost impossible online... Test things before throwing money at it.
Good luck
Yes, truck runs fine when it starts up, which is 99% of the time. It does have a bit of a stutter when accelerating at times, but is not always there. It idles fine and will maintain highway speed as well. I have just let it be as this is my once a month home remodeling scrap run to the dump truck.
This weekend I will remove the fuel tank switch and clean the contacts and visually inspect it for corrosion. I don't think that is the issue, but it will be no cost to me other than my time.
A distributor is only about $75, I might pick up one and replace that as a whole unit as the truck does have nearly 200,000 miles on it.
I guess if it was cracked then there could be condensation in there, but it is not getting wet from weather. The hood is closed of course, but then it sits under a 3/4 closed in R/V port. Again, I will have a close look at it this weekend. I plan to clean a few of the under hood electrical connections as well just for good measure.
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