i have a 1990 f-150..4.9l 6cylinder....which has been running fine but now will not start..it has gas in it..it is not the battery...when i try to start the starter turns over easy...just will not kick off...when i turn the key to the on position...i cannot hear the humming sound that the fuel pump makes before starting..which leads me to believe it is the fuel pump...but it is dual tank truck with a fuel pump in each tank...when i flip switch to the other tank....still will not start...... anybody have any sugestions.....thx..nigel

 

Have you checked the fuel pump fuses?

 

i checked the manual..and it looks like fuel pumps are on a relay and not a fuse in the fuse box...but i checked the fuses anyway and they all appear to be ok.....you think it is the relay?

 

Not sure about your '90, but on my '99 it has a fuse box under the dash and another under the hood. There is a definate listing for a 15 amp fuse for the fuel pump in the under hood fusebox. There is also a safety shutoff in case of an accident that you have to reset again to get the vehicle running. Again, not sure if your's has a safety shut off switch but our 89 Tbird did. It was mounted in the trunk. My '99 is located behind the kick panel in the right foot well.

 

do you know if their is a little plug in or wire harrness on your distributer.
If their is that might be the problem change that out and you have to have a special tool I think that it is just a really small socket but see if you have something with wires on you distributer.