6.4 Down crank no start.

[FourEyed]

Any help would be appreciated.

I have 1500 miles on a complete rebuild of my truck. 200k on the body, but HPFP, injectors, turbos, engine, etc were all just replaced.

Yesterday all was good all day. Stopped at a store, shut it off, and when I came out, it cranked over (very fast) and would not start. Got truck towed home, checked fuses, a couple simple things, and then after attempting cranking over a couple times it fired up. Shut it off and re-started it a bunch of times everything was ok.

Today went to work, all good. Then made one stop at home and truck did the same thing. At least it's in my driveway this time, but I need to get this figured out ...

- Tach is reading as it is cranking
- ICP on mini maxx reads 7.0 - 7.4 while cranking
- I can hear the low pressure fuel pump running
- Seems to turn over very fast, like there is no compression. but it ran fine until parked.
- Full tank of fresh fuel
- Only code on tuner is P0703 brake switch B circuit. I did just replace the booster, so might be left over from that.

Any suggestions on where to start looking?

 

[sootie]

Cycle the key and poke the Schroeder valve on the fuel cooler to make sure it squirts out.


need to know what rail pressure is when cranking


smell the oil on the dipstick and see if it smells like fuel

 

[FourEyed]

fuel comes out of the valve when key on. not like a spray but like a light stream.

fuel pressure when cranking is about 7.0 - 7.4

Dipstick does not smell like fuel as far as I can tell.

Just now went out and on the 2nd strike of the key it started after 6-7 seconds of cranking. truck has been sitting for 5-6 hrs at this point. It's acting normal again now. This problem seems to happen if I park for a few min and come back to re-start while it's still hot. fuel pressure reads 4.8 at idle.

Maybe the lift pump is just too weak when it's hot? it does have 200k on it now...

 

[sootie]

If you hit the valve when the pump is running, it should be hard to contain the mess...

 

[FourEyed]

dribbles out like an old man pissing in the wind.

Sounds like low pressure pump if I had to guess.

 

[DEEZUZ]

Schrader valve on cooler will just dribble

 

[DEEZUZ]

This sounds like a SYNC issue...

Did you remove/replace any of the crank or cam sensors?

 

[FourEyed]

Cam sensor, and crank sensor are about the only sensors I did not replace when going through the truck.

when it's just turning over the tach does move.

 

[FourEyed]

I ordered a new Low pressure fuel pump module, it should be here tomorrow..

Will see if that helps, I figure it has 4600hrs on it and 200k it probably wouldn't hurt to change it anyway. Do the crank / cam sensors fail like this on these trucks?

It starts every time when cold, and seems to run perfect. Just won't start when it's been up to temp and then parked for a short duration.

 

[FourEyed]

Here's a vid of what it's doing. Never heard one crank over this fast before.

https://youtu.be/pzJunbSamlQ

 

[DEEZUZ]

It's running off something. Not just cranking. Did you install a new FRP sensor on rebuild?

 

[DEEZUZ]

Whose HPFP

 

[FourEyed]

Ford HPFP from sunrise Ford.

I did not replace the sensor on the fuel rail.

 

[DEEZUZ]

Well... For what it's worth.... I just had to warranty 2 hpfps from Ford. Both with 1k miles on them

 

[FourEyed]

oh man.... what were they doing when the failed?

I'm at a loss. I need my truck. I'm out of money to just drop it off at a shop.

- Changed lpfp and it was fine for a day.
- Today doing same **** leaving me stranded. again. let it sit for 2-3 hrs and it will start.
- closing in on $20k in pulled cab 2x re-did engine twice.


Here's another video. Gauge shows from top to bottom: Voltage, fuel pressure, oil temp, coolant. Drove it 60 miles stopped twice was fine then out of nowhere:

https://youtu.be/NKXI1anD2dU

 

[DEEZUZ]

One glittered and the other one would only build 2500 or so psi.

So what's the frp this ones making?

 

[FourEyed]

at idle it seems to be at 5600. Driving around I see up to 24k at med throttle. No smoke or anything weird when running.

 

[Joush]

One glittered and the other one would only build 2500 or so psi.

Great. Think I got one of those factory glitter pumps. Don't remember having any metal in my fuel when I changed the old pump. Going to drain the tank and lines and put fresh fuel in it if it continues guess Ill have to warranty it.:shrug:

 

[FourEyed]

sorry to hear that.. These trucks are tough to deal with.

I had to bite the bullet and take it in to an actual shop. They can't find any codes with a real scanner and of course can't replicate the problem. Going to take it for a drive myself tomorrow to see if I can get it to not start. We are all stumped at this point.

 

[Joush]

What do you have for a scan tool? Just the mini maxx?