I have a 07 f350 with a 6.0 in it and I can not get it to start. I drove the truck one day and went to start it up a few hours later and will not fire up.
At first when when started checking into I was not getting any injection pressure. So then I changed the ipr and rechecked and after 9 seconds of cranking it will start to build up pressure and then quickly will climb to over 800 psi. The engine will attempt to start but will only fire on 1 or 2 cylinder and that is all. So what I have found is if I try to start it again with out shutting the key off it will build pressure right away but if I shut the key off the key for 10 minutes and try to start to it again it will take another 9-10 seconds to build pressure again. So then I replaced the stand pipes with the check valves in them and also the dummy plugs just to eliminate them. Then I hooked air up to where the pressure sensor hooks up to check for leaks and do not hear anything with the key on but when I shut the key off I hear a leak under the hpop which I assume is normal from what I’ve read. I checked the fuel pressure and have 20 psi on the upper filter housing. My ficm voltage while cranking is 47.5 volts. When I first turn the key on all the injectors go through the buzz test and sound good. With my scan tool I can’t tell if I have sync but assume it does because it tries to fire but that’s all I get.it’s cranking good. Any help would be greatly appreciated.

 

20 psi is way low. You want to have 45psi minimum. I would be looking at lower fuel filter and possibly your fuel regulator. Has it had the blue spring up grad install. Or are running the stock one. Spring could be weak.
. Post some of your readings ipr duty cycle, icp pressure and voltage and so on. It will help us see what's up.

 

I do not know if it has the blue spring update don to it but I will start there. The ipr duty cycle starts off at 85 but when it builds pressure it will drop to 45..the icp pressure will go up to 1200 and then start dropping to 800.

 

You only need 500 psi to get injectors running. What is injector pulse width, rpms while cranking,ficm main,logic and vehicle readings. Sounds like fuel or ficm problem.
you still might have a high pressure leak also. When you did test, did you go through ipr or icp?
. Ipr is a better test. You might want to take off valve covers also. You hear leaks better that way.

 

When I did the leak test I did it through the icp sensor. I had the valve covers off and couldn’t find anything. Cranking is around 200 rpm. Ficm main is 12v.I don’t have the tool to go through the ipr to do the leak test and my scan tool doesn’t tell my injector pulse width. I am going to start with the fuel pressure problem tomorrow and then see from there.

 

^^^I agree with everything posted above. Having low fuel pressure would sound pretty consistent with "tries to start" symptoms. You could have a weak HFCM, plugged primary fuel filter like already mentioned above and/or restricted fuel pickup inside the fuel tank.

 

WTF??? In your initial post, you stated your FICM_M voltage is 47.5 volts. So which is it?

 

Input voltage is 12v and out is 47.5

 

Okay, that sounds about right.

 

M-chan brought up good point on foot coming apart. It will block lines. I just had that problem a few months ago. Pressure was dropping like a rock out of nowhere. Here's a few pics. It will clog the lines.

 

So I finally made it back to do some more work on the truck and did the fuel pressure regulator kit and now my fuel pressure is at 60 psi. But the truck still would not start, it would get to a point it would just about start but would not go. So then to try something I plugged the truck in even though it is in a heated shop at around 60f. The next day I tried the truck and it started up after about 10 seconds of cranking. I left the truck running for around 15 minutes and then shut it off and tried it a few times and it started right up every time. Then I unplugged the truck and went back to it the next morning and after cranking for 10 seconds it started again. So I let it run for a minute and shut it off and it wouldn’t restart. So then I plugged it in again and tried it the next day and it started again. My question is why it is taking 10 seconds of cranking to build hpop pressure. I put air in to the system where the icp sensor goes in and with both valve covers off I do need hear any air leaks. The one thing I noticed is that if I crank it to build pressure and then shut the key off for about 10 minutes it will take another 10 seconds of cranking to build pressure. But if I leave the key on for the 10 minutes before I try to start it again it will build pressure right away. So is there a problem with my new ipr that is allowing the pressure to drain back to sump when I shut the key off or is there somewhere else I should be looking.

 

Do you have a tool to monitor or read engine outputs?
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