6.0 no hot start

[G Racing]

Ok. Got a 06 f250 with a hot no start. Truck has a sct with a tow tune. Other than that pretty much stock. When it's cold it will start like normal and run but has a big lag at take off warm or cold. When it's hot and you go to start it, it spins over just fine and try's to start. It acts as if it doesn't have enough fuel to keep running and will stop running.
It's almost like an old gas engine that wants to run after being turned off. Kind of hard to explain I guess. No smoke while cranking. Everything looks fine. Icp is 700+ while cranking. Ipr is 15-16%. Ficm and battery voltage is good. New fuel pump. Good fuel pressure. Good lpop pressure. No trouble codes. The only thing I get is a PCM fail on a KOEO self test during a hot no start. Replaced the FICM with a known good one. Started fine but would not restart when hot. It's like the injectors won't fire on a hot restart. A little shot of starting fluid and it will start and then run fine. Anyone have one that acted like this?

 

[Marty]

Air test? Stc, upper Inj o ring, etc...?

 

[04stroker]

I've had two like that ended up being an icp sensor on one and crank sensor on the other. The one I caught had no sync so I started testing things all tested good so I figured I'd replace the crank sensor with a known good one it fixed it. The other was showing it had 1200psi of icp after the engine had been off for 5 min. I replaced the icp sensor all was good after that. Both had identical symptoms to yours. Just some stuff to look at.

 

[G Racing]

Cam and crank sync is good.

I have good icp so a hpop leak isn't the issue.

 

[Derek@Vision Diesel]

Maybe this is far off, but honestly seen it before. ICP sensor on the passenger side head, it senses good pressure there. But a leak on the drivers side head that is small enough to let passenger side build pressure and read at the ICP sensor but kill the drivers side bank.

Seems odd, generally you have a leak anywhere and it all dies equally. But just 2 weeks ago we had this similar isse. It was a top oring on an injector, I had to inspect them for a good 5 minutes to even see the issue.

Maybe worth checking out before you pull your hair out Jason

 

[G Racing]

I'll pull the icp sensor tomorrow and put the mechanical gauge on it and see if it's telling the truth lol

 

[04stroker]

Good idea

 

[Mdub707]

Just try unplugging the ICP sensor and see if it starts when it's hot like that?

What is desired ICP when this is going on? Actual is 700ish? IPR is only 15%? Does it creep up at all when it's not starting and you keep cranking?

 

[SEABEE08FX4]

I know its saying you have good pressure but I'd check the oil rail plugs or stc fitting.

 

[Vozar]

Where are u checking fuel pressure at? What kind of fuel filters are u running?

 

[BlueWaffle]

i know a bad stc fitting will throw a no hot start but I'm not sure how that will effect ICP that you're seeing.

 

[Mdub707]

Being an 06, if it hasn't been done I would just do the STC fitting and new dummy plugs/stand pipes anyways, if you have to dive in.

 

[G Racing]

It already had a new hpop and new fitting put in last year.

The icp sensor was bad. It was showing 300 psi with the engine off so when it was telling the computer that it had 700 it only had 400 and the ipr duty cycle wouldn't increase to build pressure. New sensor fixed the issue.

 

[Mdub707]

Nice!