Cold starting issues

[AWD EXPY]

In the mornings or even after work, the motor won't fire. I have a brand new battery that cranks the snot out of it. When it's cold, I turn the key to ign, then wait a few seconds for the sound of the fuel pump clunk. Half the time I have to repeat that a few times before it starts.

After it does fire up, there are no issues in running or acceleration. Should I suspect the fuel pump or filter? It seems that if one of those was suspect, there would be issues running or accelerating.

Could I be losing fuel pressure somewhere? Fuel pressure regulator? Pump?

I suppose I can't rule out ignition circuits.

 

[toms89]

What your describing is definitely sounds like a fuel issue. Multiple turns on the ignition switch before cranking builds fuel pressure back up.

You can be losing fuel pressure through your fuel pump check valve, fuel pressure regulator, or leaky injector. It seems fuel pump failures are most common though. To confirm you need to check fuel pressure at the rail. If it runs fine it may just be bleeding down over time via one of the above items while turned off.

I would change fuel filter first if you have not recently as this is a tune up item anyways. If it helps great.

 

[toms89]

Straight out of my 2000 Expedition service manual:

Engine running kPa (psi) 193-310 (28-45)
Key On Engine Off kPa (psi) 242-310 (35-45)


Fuel pressure drops with vacuum. (motor running with closed throttle)
The more throttle you give it the less the vacuum and higher your fuel pressure. Should be about the same as engine off. (zero vacuum)

My experience has been about 39-45psi with vacuum source disconnected and about 10 psi less with 20 inches of vacuum.

 

[AWD EXPY]

Ironic that in '87, my '87 tempo had a fuel pump go bad @ 12,300 miles. the warranty was over at 12k, but ford did cover a bit on that one.

 

[AWD EXPY]

Well saturday I replaced the fuel filter and so far, so good. Starts well every time and no cutting out.

I used a o'reilly store filter removal tool (borrow). In the box it came in...2 of them, the 5/16 was labeled 3/8 and vice-versa. Cheap plastic. I had to cut down 3/8" so I could fit it on the filter line. Really a reject tool. But the filter seems to be doing well.