I've found myself the caretaker of an 94 F150 thats been sitting 3 years +. Aside from the obvious things like tires, fluids, oil the truck does not want to idle. I have to baby it for a while and give it gas when the motor tries to die. eventually the truck will idle on its own but its a little unpredictable. From my research online the most likely culprits are:
Idle Air Control Valve: The most obvious one. I will clean it, maybe buy a new one if all other options are exhausted.
Throttle position sensor
Alternator/battery: the battery was disconnected, haven't tested it but it could be bad and causing problems that the computer will try to compensate for from what i've read
Vacuum lines
The gas is also old, not older than a year though
If anyone has experience with these trucks I'd like to know what to look for first. Thanks
I would measure fuel pressure. Sitting for years often causes fuel system problems.
Idle Air Control Valve: The most obvious one. I will clean it, maybe buy a new one if all other options are exhausted.
TPS
go ahead and check. But they don't usually go bad from sitting.
Alternator/battery: the battery was disconnected, haven't tested it but it could be bad and causing problems that the computer will try to compensate for from what i've read
Even disconnected, batteries will self discharge and cause permanent damage. So go ahead and get them tested ... it's free after all. It's unlikely this is causing poor idle though.
Vacuum lines
Yes. One of the most common causes of poor idle.
The gas is also old, not older than a year though
might be worth siphoning out before it causes more serious problems.
