I have an 89 f150 4.9L dual tank, the truck has been dead(battery) for days got it charged and there is a click then a hum. Key is out of the truck but doesn't stop. Saw the fuel line jumping but don't understand why the pump would run with key off. Plus I go to start it and it turns over but will not start. Please help

 

Smack the PCM and fuel pump relays couple times see if they are hanging up.

If not suggests has a ignition switch problem, its hanging up shorted out internally or actuator rod has issues.

Gonna take some testing narrow down the problem.

 

Fuel pump relay is going bad. Replace it

 

I replaced it. No more humming but still wont start. Thought it might be flooded but after sitting a few hours and a few tries still nothing

 

I don't understand why it would be ignition. It turns over. Gets to start rarely but wont start. Really confused.

 

Trys to start rarely*

 

Was part of the suggestions for pump running with key off/out.

What is it lacking when attempting to start?

Does it have good spark?

What is the fuel pressure?

If has both fuel and spark how does the timing check out?

Bring #1 cylinder up on compression stroke, does rotor point to number one?

 

Has a spark. Fuel pressure is fine. Timing is fine. Makes no since

 

Something I noticed was I smell gas after I try to start it and the fuel pump stays running with key on. I can sometimes get it to start but putt putts and dies after like 10 sec

 

The spark plugs are probably fouled with fuel.Change them. Change the relay, like you were told in the begining of the thread, so it stops running with the key off.

 

I did replace the relay and it stopped running with the hey off . But its running nonstop with the key on.

 

Engine not running? If so adding to that your other comments "Something I noticed was I smell gas after I try to start it and the fuel pump stays running with key on. I can sometimes get it to start but putt putts and dies after like 10 sec" sounds like your computer might be the issue.

 

Check the computer ground connection that goes straight to the negative battery cable. If that is not making good connection, it will act just like you are saying when trying to start. Will crank and give spark, but won't get enough fuel to fire off.