99 super duty 7.3 L will crank but it wont start. I've changed the high preddure fuel pump and the oil sensor, the IDM, PCM, injectors, checked all fuses and relays and wiring. I dont know where to turn next. Any help would be greatly appreciated. P.S Getting good fuel pressure at head but injectors seem like they wont open?
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these trucks use a oil fired fuel injector, if your high pressure oil pump has eccessive wear or if your oil to broken down from being run to long between oil change, it will not build enough oil pressure to fire the injector once the oil is thinned out from being hot. An oil leak in your high pressure oil system can cause same problem.
dies the truck restart once it cools off? it is very common for th 6.0 to have high pressure oil issues on a hot soak. they will run till the cows come home but once shut off they can not build up enough pressure by cranking speed alone to start truck until it cools down and the seals become rigid enough to bridge the gaps they are sealing in the first please. if this is the case. it may be the STC fitting ojn the back of the high pressure oil pump (intake and turbos must be removed to check) or possibly the branch tube o rings have worn. the branch tubes are located under the valve covers and supply the fuel injectors the oil they need to perform their "power stroke"...
yes they are you stated that you have mech oil pressure did you install a gauge?. this is a fuel line pressure sensor on the right bank at the frt of the head this sensor is rail pressure that high pressure oil pump creates check you pressure there that will elimnate that head the other side is a little more of a pain to test. one other thing to keep in mind is that the cranking speed is very important, and have you checked the oil level on a 7.3 deisel if you are more than 3 qaurts low on oil you will trap air in the high pressure pump. this will cause a hard start our even a no start
i had to replace my oil pressure regulator sensor it contols the oil pressure required to have the injectors open and spit fuel, if you replaced it and still no start replace the the cam position sensor