Ford 6.0 - No start issue

This topic contains 1 replies and was last updated by gary-remster 9 years 5 months ago
Author
gary-remster
November 18th, 2011 8:49pm
Post
I have a 2006 Ford E350 school bus with a 6.0L that starts fine when cold but after it warms up and you shut it off and go to restart the engine it will crank but wont start until it cools down. Already replaced batteries and FICM. Any suggestions?
jim-owen
November 19th, 2011 12:24am
Power Strokes and the HUEI fuel systems can be a lot of fun. Some initial questions:

Is the engine cranking at normal speed?

When the engine is running, does it have any idiosyncrasies that have been relayed to you, like rough idle, overheating, noises, gauges fluctuating?

Have you checked the glow plugs and the glow plug relay for normal operation?

Check the heat sensors and gauges for proper ape ration.

Do you notice abnormally high pressurization in the water cooling system?



Some diagnostic suggestions: 1st: the Cooling System. Get the vehicle running and warm it up. Take a temp gun and check all the critical places where heat can be tested and record them. Drive the unit several miles and retest with the heat gun. The comparison temps may give you an indication.



The 6l engine has a history of blown head gaskets and broken head bolts. Just as this happens, it most commonly this shows itself as a pressurized cooling system, sometimes referred to as the Volcano Effect.



Another problem may be an EGR valve or cooler heating the water and pressurizing.



Next: Fuel System. You do need to understand the HUEI system to diagnose this system. The HUEI oil pump uses engine oil to pressurize a rail system to the injectors which is used to FIRE the injectors. The rail has a sensor that monitors the oil pressure, and a valve that uses pulse width solenoid to limit the pressure as to the computers decisions.



Inside the injector is a intensifier piston. The piston has a large end and a small end, the large end is about 6 times larger. The pressurized engine oil, up to maybe 1500 lbs would then deliver 10,000 lbs+ for fuel injection pressure. A computer controlled solenoid on the injector controls when the pressurized engine oil is trapped and fires the injector.



To test all this out you need the appropriate scan tool for the HUEI testing. You will need to test the oil pressures at various speed and loads, the fuel supply pressures, perform injector tests like the buzz test.



If your problem is a result of your cooling system, and you have a head gasket problem, consider using studs instead of bolts for your heads. This is a much better fix and will last a lot longer. With a van, enough room can be problem.



If it proves to be an injector problem, lack of adequate maintenance specific to the HUEI is often the culprit. Check out this site:



http://powerstrokehelp.com/7.3liter/inj_tune/1of4.asp



I hope this helps. And when you do find the problem, be sure to come back and get us educated.

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