cudacrzy

i have a 96 f250 7.3 the day after christmas i went hunting, attempted to drive to get breakfast made it 100 feet and the truck died. it acted like it ran out of gas, all though it did not. it was not a fuel problem, we determined that. There was nothing wrong with the high pressure oil pump, replaced the low pressure pump (and the water pump while we were there) and it still wont start. it will crank, but will not start unless we prime the low pressure oil pump. i have been told that there may be a problem with the oil pick up. i have also been told i have to remove the engine to get to it. tell me it aint so and if it is what do i have to do, start to finish if you have the time, to remove the engine. the chilton and hanes manuals are a joke...help please!

ModMech

Hmm.

Lets start off with how this system works. The oil pump (engine oil pressure) supplies oil to the internals of the engine, and the HP oil pump. The HP pump has a reservoir as part of it's mounting. The ONLY way to "prime" it, is to fill the reservoir by removing the 1/8" NPT plug on top of the gear housing near the upper rad hose. The HP pump supplies oil to the injectors. The pressure is controlled by the ICP (Injection Control Pressure) Solenoid. If it does not get +12Vdc, the engine will not start. If it sticks open, it will not start. Without a pressure gauge and a special "T" fitting rated for in EXCESS of 3000 PSI, you cannot troubleshoot the HP system very throughly.

Now, does your tach move while cranking? If not, replace the Cam (CMP) Sensor.

Do you get voltage to both sides of the glow plug relay with the "Wait to Start" light on? If not, replace that relay.

The MOST common reason for a no-start is the glow plug relay, the second is the CMP sensor. Aside from that, if it has fuel and oil, it should start.

cudacrzy

did pull the sensor to prime hp res. truck started fine but no oil pressure. shut it down. was told the pickup tube could be stopped up or cracked. pulled the engine today & 7 hours later the inside is spotless clean and the pick up looks great. any suggestions???? i'm going nuts i have 10 grand tied up in this truck only had it 2 months and can not afford a new engine.... is there maybe an oil gally plug or something that could have come loose or broke??? what about ???cooling jets???? where are they and how to inspect? thanks ahead of time for any help.

ModMech

You do NOT have an "oil pressure gauge". It's a "mechanical light". It indicates that either you have pressure, or you don't. The "sender" is not really a sender at all, but a 5-7 psi switch. It is VERY common for the switch to fail, and when it does you'll show no oil pressure.

The only way to KNOW if you have oil pressure is to use a mechanical gauge (engine oil, NOT HP oil).

Since you need to fill the re.s to get it to start, I'd think the engine oil pump is toast.

cudacrzy

used mech gauge before i pulled it out no pres. new oil pump still np pres. pulled engine no trash in or damage to pickup. any suggestions??

cudacrzy

I figured out what was wrong ( actually my wife did). the check valve/ restrictor that screws into the inside of the front cover came out. after removing the front cover a 3/4" or there about size plug/restrictor fell out on the ground. close inspection of the motor revealed that is a fresh rebuild ( new every thing and still has all crosshatch on cylinders and all is spotless clean).whoever put it together either did not tighten it enough or should have used thread sealer.i used teflon poaste. any how all is good in powerstroke land now. Hope this will help anyone in the future