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Discussion Starter #1
I've had the car about 3 months and it has 115K miles on it. Appears to have been very well taken care of. The problem that I'm trying to figure out is why it is sometimes hard to start when cold or warm. Here's what usually happens:

With a cold engine.
It will often start and run like new, but sometimes it starts but stumbles for 3-5 seconds and dies.
On the next attempt it will always start and run normally.

When warm.
About half the time it will start normally with 2 seconds of cranking. Perfect!
But sometimes it takes 6-7 seconds of constant cranking to start and when it does it runs fine. I've never had the stumble\stall start when warm.

I have noticed that if it doesn't start within the usual 2-3 seconds I can cycle the ignition and it will start normally.

Battery is new.

Anyone else experience this sort of thing?
 

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When its cold cycle the key 3 times but let the fuel pump prime each time, then try to start it. To me it sounds like a tired fuel pump. I suggest getting a fuel pressure gauge and checking fuel pressure after cycling the key when cold, while running and checking for pressure loss after turning the car off.

https://troubleshootmyvehicle.com/ford/4.6L-5.4L/how-to-test-the-fuel-pump-2


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Just to add to what 85 LTDCrownvic said, there are two check valves in the fuel system. One is at the fuel pump, the other up by the fuel manifold or regulator, though I've never looked for or verified that one. The purpose of the valves is to maintain fuel pressure in the system for quick/easier starting. If the valves leak down, and they do, it will take a few seconds to build pressure in the fuel line and injector manifold causing the problem described. My V-10 F350 acts exactly as your your CV. For lazy me it's easier to just wait a second or two with the ignition on and then crank it over, than to change the fuel pump assembly that contains the check valve. Also, remember that older cars are like old dogs. They seem to develop their own personalities. You can either shoot them or learn to love 'em.
 

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Didnt know about the valve by the pump. Ya learn something new every day...


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Discussion Starter #7
That makes sense. I'll see if I can rent a gauge and confirm.

I had it checked for codes and it came up clean. Many thanks.
 

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Discussion Starter #8
Got it.

The fuel filter was bad, probably the original. Starts, idles and runs silky smooth every time cold or hot.

I haven't touched the plugs yet. Right now I'm getting 22+ MPG and don't see a need to do anything else at the moment. All other maintenance is caught up. Changed the 22 year old lower rad hose today. Broke the ears off the OEM hose clamp and couldn't get it to expand. What a PITA that was.

Thanks!
 
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