Hard start when warm 1999 Ford F-150? - 1

I have a 1999 Ford F-150 that has a hard restart problem. When the truck is cold, it starts up no problem. When the truck is warmed up and I attempt to start it, it cranks about 15 times before it starts. I have already checked the fuel pump (running @ 34 psi) and the fuel injectors as I thought this was more likely a fuel related issue, but now I don't think it is because they are all working within spec. Does anyone have any ideas on what this could be?

I have a 1999 Ford F-150 that has a hard restart problem. When the truck is cold, it starts up no problem. When the truck is warmed up and I attempt to start it, it cranks about 15 times before it starts. I have already checked the fuel pump (running @ 34 psi) and the fuel injectors as I thought this was more likely a fuel related issue, but now I don't think it is because they are all working within spec. Does anyone have any ideas on what this could be? First the basics, make sure both battery terminals are clean and. Tight, next, look under your truck on the driver side for the fuel filter. This may require a special tool to get the fuel lines off. Just go to the nearest auto parts store to get this and while your there, also get a fuel cleaning additive, the fuel filer, and a repair manual for your vehicle. No the owner's manual will not do!
I suggest the filter because most people are not aware they had one under there.

Go to the auto parts store to also get the codes. They can also tell you what the codes mean.
You will also read that first chapter in your new repair mainual and go over all the maintenance issues of your truck. You may find low coolant or worn broken or rotted vacuum hoses, loose Mass Air Flow air tubes or the realization that your ignition coil, ignition wires and spark plugs may need changing. Do these as a set. They all wear together and develop higher resistance with more underhood heat I live in the UK so the F-150 is unfamiliar to me. But if it has a gasoline engine and if in 1999 they still had a conventional ignition coil then you're describing classic symptoms of an overheated ignition coil.

When it's been left a while to ensure it's at ambient temperature measure the resistance of the primary and secondary winding and compare them to manufacturer's specifications. Then dip the body or the coil in a bucket of very hot water for about ten minutes and compare the results. A big difference shows a faulty coil. Most people don't do all that, they either get a repair garage to test the coil on a coil-testing machine (a tool usually only owned by professionals) or simply swap for a known good coil.

If it has a distributor with an attached condenser/capacitor (a small metal cylinder about an inch long and hard an inch wide) then when they get hot they can also cause the same problem. If that's the cause consider upgrading to fully electronic ignition as modern replacement condensers are now of appallingly bad quality.

Other potential causes also exist, but they're the two most common and are easy to check. Its the air idle speed motor look for a round pill bottle size thing on the intake its silver in color

I live in the UK so the F-150 is unfamiliar to me. But if it has a gasoline engine and if in 1999 they still had a conventional ignition coil then you're describing classic symptoms of an overheated ignition coil.

When it's been left a while to ensure it's at ambient temperature measure the resistance of the primary and secondary winding and compare them to manufacturer's specifications. Then dip the body or the coil in a bucket of very hot water for about ten minutes and compare the results. A big difference shows a faulty coil. Most people don't do all that, they either get a repair garage to test the coil on a coil-testing machine (a tool usually only owned by professionals) or simply swap for a known good coil.

If it has a distributor with an attached condenser/capacitor (a small metal cylinder about an inch long and hard an inch wide) then when they get hot they can also cause the same problem. If that's the cause consider upgrading to fully electronic ignition as modern replacement condensers are now of appallingly bad quality.

Other potential causes also exist, but they're the two most common and are easy to check.

Its the air idle speed motor look for a round pill bottle size thing on the intake its silver in color