Iffy ignition

[inkybandit]

Recently, upon turning the key the truck will start (or almost start), then get weak and stop. I'll turn the key again, and it starts no problem. This startup failure only happens the first time I try to start it in a day; the rest of the day it works like a charm. Is this an electrical problem or what? and how do I fix it?

Thanks

 

[Wrench]

I would do a fuel pressure test (KOEO) before first start. When was the last time you changed your fuel filter?

 

[inkybandit]

Replaced it last summer with an oil change

 

[inkybandit]

I did a fuel pressure check and it was pretty low (31 psi). After I shut off the engine, pressure dropped pretty rapidly back to practically zero. I'm under the impression that it should stay pressurized for a few minutes, correct?

So what are the likely candidates: pressure regulator, pump, filter?

 

[MrShorty]

Was it 31 psi with the pump running or was that after the pump shut off?

I forget exactly what the spec is (if you have a Chiltons, they have a nice fuel pressure diagnosis chart in there), but the system should not drop more than a few psi after 2-5 minutes. Usual culprit is the check valve in the pump.