Normally my truck is driven 365 days a year. Since the beginning of Dec. I've been driving the mustang on the weekends and sometimes a day or 2 thru the week. Yea fun factor. There might not be a problem just that I drive my truck to much to notice.
Anyway I've noticed that after sitting a couple days of sitting my truck turns over twice as long to fire. I haven't timed it or anything its just that I know how my truck is and when it usually fires it doent. Now I'm only talking splits of seconds. In still on the first time I turn the key. Just takes alittle longer to start. So this morning I just thought about maybe fuel pressure maybe dropping alittle.
Sorry if this doesn't make sense and I appreciate all ideas.

 

Mileage, Mods, Maintenance?

When is last time fuel filters changed? Oil filters? Are they OEM?

Codes?

 

agreed. i have a airdog II now but before with the stock pump i was putting out 35-40 psi. changed the filters and got my 50 psi back. i do reg maint, but changing the fuel filters out every 25k or so is what is recommended i think. correct me if im wrong gearloose1

 

I had a stumble today.. and a suspect is fuel filters (and gel / wax dropout).

Or carbon... or...

 

I had a stumble today.. and a suspect is fuel filters (and gel / wax dropout).

Or carbon... or...

 

No mods. Maint. Regular. Fuelfilters every other oil change.

 

Mark has a "no start" diagnostics that you might start with..

Off hand, I would check fuel pressure.. then go from there.

 

I am new to diesel fuels, In the Midwest are there better stations to buy fuel. I have noticed a longer start after fueling at a BP station. when I use the shell fuel it seemed to start quicker.

I apoligize if this is a basic question.

Thanks

Bill

Sent from a small device that often second guesses my word selection.
Please excuse inaccurate words or typos.

 

I'm not in a no start situation. I'm in a slight delayed fire. I don't turn the key more once.

 

If your batteries are more than 2 years old, give 'em a good bench charge.

If your batteries are more than 3 years old, replace them. Yes, even if they're marked/marketed as 84-month batteries.

Cold starts are hard enough as it is on batteries, and a PSD is harder to crank than most other engines are. Additionally, FICM's are EXCESSIVELY finicky about voltage requirements.

Slower than "normal" starts are the first sign of weak batteries.

-blaine

 

I'm going to take this opportunity to ramble a bit about Ford's **** poor glow plug and fuel pump strategy when starting the 6.0. IMO, a lot of the slow start problems are attributed to the strategy. I have an AD2 fuel pump with an internal regulator set to 70 psi installed. On cold mornings (around 20°F) when I turn the key on I get around 50 psi fuel pressure. Why? Because the glow plugs are drawing so much current that it produces a voltage drop. When the X starts the fuel pressure remains at 50 psi until the glow plug relay times out (about 10 to 15 seconds) and the alternator switches on. Then my fuel pressure will go to 80 psi since the fuel is cold and thick. Once things get warm then my fuel pressure goes back to 70 psi and if I dog it, it will fluctuate between 65 and 70 psi. I have no engine fuel filter or pressure regulator. My fuel pressure regulation, filtration and return occur at the AD2. My setup is dead ended from the AD2 to the FIs.

Now if I am getting a 15 to 20 psi fuel pressure drop with my AD2 setup what do you think the OEM fuel pressure drop is at start up? Normal OEM running fuel pressure is around 45 psi. So with the glow plug relay on and the fuel pump running I would venture a guess the fuel pressure on start up is between 25 to 30 psi. According to some, that is too low. The new Ford blue fuel pressure spring raises the running pressure to about 60 psi. Around the same as the BB mod. When I installed the GDS spring a while back, my running fuel pressure was 105 psi. According to some, that is too high, so I called GDS. GDS said IH 6.0 fuel system engineers told them the system MAX design operating pressure is 120 psi. Ford says the MAX operating pressure should not exceed 80 psi. Sounds like a bunch of politicians.

Anyway, when I had the GDS spring installed prior to the AD2, the X started easier and the power and acceleration were awesome. Higher fuel pressure = better throttle response and more power but reduced fuel economy.

Well, FWIW that is my fuel pressure/glow plug strategy rant.

DSMMH

 

I have the stock fuel pump, filters, regulator, etc, with the updated fuel pressure spring. My fuel pressure goes to about 65 PSI at key on, and remains there. Starting, idling, WOT, it stays right around 65, maybe dropping 5 PSI momentarily at WOT.

That is the whole purpose of a fuel regulator, to keep the fuel pressure constant. If your pressure is dropping that much because of lower voltage at startup, then you either have a problem with your regulator, or you have a really low voltage problem.

Also, I have heard people claim that increasing the fuel pressure increases power and acceleration, etc. It is something I did not experience when I upgraded my regulator. Frankly, I don't see why it would happen. All fuel pressure does is fill the injector. The amount of fuel actually injected is determined by HPOP pressure and pulse width. Unless your fuel system was delivering inadequate supply before an upgrade, you shouldn't see any difference after an upgrade.

 

P.S. to the OP. If you're only talking a few seconds, frankly I wouldn't worry about it. It wouldn't hurt to check the voltage at the battery. Get a reading at initial key on, cranking, just after starting, after 2 minutes when the glow plugs shut off, and after it has run for 15 minutes or so.

At key on, I've seen down as far as 11 volts. If I understand correctly, cranking should go below 10 volts, but I think people have reported as low as 9. After it starts with the glow plugs still on I can run down around 11 and after the glow plugs go off it runs up to about 14.2 until the batteries are charged back up, then I run around 13.4.

As long as your voltages are good, I wouldn't do anything. There isn't any point in fixing what isn't broke.