4.0L SOHC 2001 Trac - Long Crank / Hard Start

[Evan6ardner]

I hadn't seen anything definitive (likely because it can be multiple issues) as to why my truck takes a while to crank on a cold start.

I notice if I prime the fuel pump twice and wait a second or two, the engine will crank and start up very well. If I just turn it in, it will crank over for a long time and eventually turn on. Or in some cases, when I stop cranking, it'll kick on.

I've changed my fuel filter. I've checked my fuel pressure... 60psi almost immediately. I've changed my spark plugs. I've changed my spark plug cables. I've changed out the idle air valve unit.

Someone at an autostore claimed their 4.0L SOHC f150 (not sure of the yr) has the exact same issue, and suggested that it was maybe the fuel pressure regulator or a crank angle sensor. Anyone have any feedback?

 

[Evan6ardner]

No thoughts? No one else has a problem on their ST? I've got 206k miles.

 

[2000StreetRod]

fuel pressure?

I'm not familiar with your Sport Trac but your symptoms sound like a weak fuel pump or a leaking fuel line or check valve internal to the tank since cycling the ignition key results in a quick start. See Ford Explorer Ranger Fuel pressure test procedure . Does your fuel pressure rapidly bleed down?

 

[Evan6ardner]

I'm not familiar with your Sport Trac but your symptoms sound like a weak fuel pump or a leaking fuel line or check valve internal to the tank since cycling the ignition key results in a quick start. See Ford Explorer Ranger Fuel pressure test procedure . Does your fuel pressure rapidly bleed down?

I will test it again tonight. I recall last time testing it (with these symptoms), the pressure shot up to 55-60psi very quickly, and didn't bleed off within the 5 minute window I checked.

Thanks for the link. I'll see what I can find out.

 

[01STrunner]

The 4.0 seems to reject the "high end" spark plugs. The best bet on replacing spark plugs is motorcraft platinum or a similar plug. If you put better plugs in it may be affecting the engine. Just info I've read over time. GL

 

[Evan6ardner]

Sorry for bumping an old topic, but I recently tested my fuel pressure again.

I was able to see the pressure stay at 0psi until I primed the pump 3 times after it sat for more than 30 minutes. After priming 2-3 times, the pressure hits 60, and then falls off to 0 within about 20-30 seconds. When the truck starts, it runs like a champ.

I know many cars have FPR and check-valves in the fuel pump. Does this sound like a bad fuel pump check valve? Others have told me that ford pumps don't really have a "check-valve" , but rather a flow restrictor.

Anyone know more? I'd like to do the task over the holidays, but would prefer not to replace the pump if it is something else. The fuel filter is relatively new.

 

[Hoppy]

Evan6ardner,

Have you found out your problem yet? I own a 2000 SOHC XLS Explorer and according to my wife the truck is hard to start now and again. Last night it took 7 attempts before the truck fired up.

I am not sure, but I did have an issue with my rear wiper motor not cycling. I swapped relays in the power distribution box and got the wiper motor working again. Unfortunately I swapped it with the fuel pump relay and the truck wouldn't start because of the bad relay now on the fuel pump circuit. Perhaps this could be the problem?