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03 F150 taking longer to start

Occasionally my 2003 f150 takes longer to start than Id like. Lets say 2-3 seconds before it fires. It turns over plenty fast so Its not a battery crappin out. Runs great once it lights. I replaced the spark plugs but that didnt change it. Once again this just happens every now and then. 120k on the clock. Should I suspect a fuel pump showing its age? Oh I should also note I changed the fuel filter a few months back.

If you don’t have a fuel pressure tester you might consider removing the cap from the pressure testing port. Let it run a minute and shut it off. Allow it to sit for several hours and then depress the Schrader valve in the port with a tiny screwdriver tip, matchstick, or what have you. Note if gasoline spurts out under pressure or whether it dribbles.

The latter could point to loss of residual fuel pressure. In most cars this can often mean a check valve in the pump leaking off but (and I’m hazy on this) I think some later model Fords beginning in this era used a fuel pressure sensor and the pumps did not have check valves. Hope that helps.

I vaguely recall a dribble when I depressurized the system to swap the fuel filter. Im sure what you’re talking about is whats going on.


I believe the Fords with the fuel rail pressure sensor don’t have a test port

Ford seems to have one or the other, not both on the same vehicle

That’s what I’ve noticed, for what it’s worth

In any case, I’m fairly confident OP’s truck does not have a fuel rail pressure sensor

Get the fuel pressure tested. I suspect a failing fuel pump. Fuel injection requires a “steady” stream of pressurized fuel in order to work properly. The fuel pressure test will determine if you have a problem along those lines.

You can’t check for fuel pressure at the Schrader valve if the vehicle sits for more than 30 minutes.

When the fuel pump stops running, it takes about 15-30 minutes for the residual fuel pressure to bleed down to zero PSI. So if you depress the Shrader valve after this amount of time there will be no fuel pressure.


Fuel pump should buzz for a couple seconds when the key is turned to “ign”, pressurizing the line. But after it starts go back near the tank maybe even open the fuel cap and listen. If you still hear that pump then it is probably failing. Have a mechanic check the pressure after that to be sure.