I need some advice what direction to go. My 03 f550 has studs, egr delete. Starts fine when cold as soon as it warms up it quits when you place into reverse or drive. When you go to restart just turns over and won't fire with no smoke. When it starts cold and running icp is the same is desired and ipr is between 35-50 %. When you start to drive slowly from a dead stop it hesitates like you rapidly let off the gas, then a minute later over drive flashes. It will do this a couple of times, if you shut the truck off and start it up it is all good to go until it warms up and then it dies if you stop and put in reverse. Then no start, icp is 350 ? Let it cool down and starts right up.
Do I have more then one problem? If you push tow haul it goes into fail safe in a few miles.
Are these problems electrical or is the hpop and trans on the way out.
120000 miles I believe original hpop
New icp and ipr.
Re soldiered ficm to be sure not a bad joint. Always at 47.5-48.5

Thanks in advice

Fat and frustrated.

 

Sounds like a wiring issue. Check around the degas bottle area for chafing. Had one in the shop last week for the same problem. Bad wiring. Almost the same symtoms as the band in the tranny going.

 

i am having a simular problem the truck turns on fine when cold no problems or issues i can drive it all around but whe i turn it off it will not turn on again ill let it set and try it in the morning and it will crank up once again weired i have checked the ficm and it testes good 47v to 48v batterys also test out good any ideas what this could be

 

That no start problem does not sound the same as the first post. You say when the oil is cold it will start and run. When you say the oil is hot it won't start.? Has the oil rail Gus and tubes been changed? If not then you will know where to start. Oil pressure is a must in a 6 liter.

 

im not shur if if the tubes have been replaced i just got the truck a month ago weather was nice has no problems but when the cold weather started to aproach thats when it started acting up so i start on the tubes like you said Thanks !!

 

If you have a scanner check the icp pressure. It should have 500 psi to start anything lower then that it won't start. Cheers

 

i dont have a scanner but im thinking of taking it to a deisel shop here locally so i can get it diagnosed see what they say its just hard to trust anyone when your not in your home town.

 

I'm running into the same problem on my 2004 6.0, but I just had the hpop and pipe seals done 3 months ago the other day started goving me problems starting when warm. Let me know what your problem was

 

Have an update. Installed a new hpop as recommended by a number of diesel techs.
Truck started fine idled great. Got to operating temp stalled when placed in gear. Will not start! Ipr is 85 when cranking, icp is 350, ficm is synced and at 48 volts. I unplugged icp it then showed 1350 icp but still would not fire. Borrowed a buddies ficm and installed it 2hrs later, started and then stalled same readings. What am I missing?
I am going to cry like a 10 year old Ron burgundy
Any advice is appreciated.

 

Father in law went thru this a little bit ago... Problem was oil system itself. Replaced oil cooler and completely flushed/cleaned the oil system and no more problems. Took us a while to figure that out. But there was something somewhere in the system that once it got warm, then eventually just after a couple minutes of idling, it would cut off oil pressure to injectors and that's all she wrote

09 qsb, parts fell off, some got add, car seat and hot wife mod adds about 50hp right?