Truck starts, runs great, and sometimes won't start up again till the next day...Why?...battery is good...could it be fuel filter?

Had a 89 cavalier did that start then die it map sensor. Also check ground wires if the become too corroded they won't start sometimes just run weird

pull positive off battery reboot computer try that

try replacing fuel injection fuse.

Fuel filter or weak fuel pump?

remove the pump and check for sediment in the pick up gauze filter ,if bottom of tank clean then check the connections on the multiplug ,if ok then drive it till it stops and then check it again as the fault is their but its finding it at the right place at the right time

sounds like a fuel pump or filter problem. replace filter first its cheaper than a fuel pump.my fuel filter on my 01 530 was under the driver side half way back along the bottom rail of the car.i had to remove the aero plastic with a plug puller that gave me acess to it.try and replace that first. if it doesn work its prob.fuel pump.

What do you mean by trouble starting. Do you mean extended cranking time for the first start? If that is what you mean, than you may have a bad fuel pump check valve in the tank. The fuel in the fuel line drains back and requires an extended crank time to push the fuel back up to the injector rail for a start.

did you reset the alarm/immobiliser system every time the power was disconnected???

sounds like your fuel pump is going out. One thought might be that the fuel filter is causing enough resistance to over heat the pump. I would check the fule pressure to determine a free flow of fuel.

This could be a multitude of different problems. I'd suggest some simple T&E and find what's going on. Start with the simplest solutions first. Tune up, plugs, wires, air filter, oil change, and the like. Then see how it acts after that.

Going with that, if you still are having problems it's time to go into more detail with your search. Start checking things such as your spark, fuel pump, fuel filter(s), catylitic converter, and even check your fuses for blown fuses.

In the case none of this works, it's more then likely that you'll have to end up finding a decent mechanic. They can start testing other parts such as the cylinder compression, valve adjustments, and even internal wear if need be.

One big question however, if there is an engine light on, get it checked with an OBD reader at autozone, advanced, or the like of auto stores. I hope this helps you out bud.