Help Needed I'm stumped here guys. Could I get some input?

[Eubee]

Finally got around to working more on my F250. Here is where I stand with it now:

-Truck is still a crank no start.
-ICP replaced, reads 550PSI during cranking
-Fuel pressure manually read at ~47PSI during cranking (from test port on secondary fuel filter housing)
-Oil level is good
-HPOP shows no physical damage
-IPR proven to be properly operative by applying shop air to oil log and applying battery voltage to IPR
-High pressure oil system does not leak when shop air is applied to oil log and IPR is closed
-IPR did have some debris on screen, but not enough to block oil flow
-Being that the injectors are in parallel (and therefore not in series) with each other on the oil logs, I do not feel that a bad injector could 'block' oil flow in the system. If I am wrong in my thinking here, please help me understand.

Dealer claimed that the truck was not building enough oil pressure to start engine. They claimed the HPOP would probably need replaced. If the High Pressure Oil System is operating properly; is it possible for the HPOP to build proper pressure even if base engine oil pressure is too low?

Thanks for any help.

FWIW: I agree that it is way easier to work on that engine with the cab off!

 

[Scot]

I can't help with your problem. I just wanted to say sweeeeeet set up there Only thing better than lifting your own cab, is the ability to do it inside. What was your lifting mechanism? ratchet straps?

 

[Eubee]

... What was your lifting mechanism? ratchet straps?

Yep. They worked very well. The two on the front are 5000lb and the two on the back are 10,000lb. I was going to use chainfalls, but decided to go with straps for they are less prone to scratching the paint.

 

[Jetpilot1]

Eubee

It sounds like you have a scantool and are able to read the PCM.

I assume you have no codes set.

You say the ICP pressure is 550, which is good enough to fire the injectors. Is this a mechanical pressure reading or a scantool reading? The scantool ICP pressure is a calculated pressure, and the injectors really require .8-1.0 ICPV cranking minimum to fire the injectors. Look at the scantool to ensure this minimum voltage vs the calculated ICP pressure.

Anyways - on a cold Engine oil crank no start - check out the glow plug system.

Do you get the injectors clicking when the key is first turned on before activating starter?

You note that the IPR screen had some debris. Was it broken? IPR's can be damaged by bad HP pumps. That screen should be clean. If its broken then you should check the reservoir screen in the oil cooler for debris. - bad hp pump.

Is the crank fast enough - its impossible to tell by ear but you need 100RPM minimum, load test your batteries.

 

[Eubee]

...

I did not know ICP pressure was calculated. That means it could maybe still be the pump then.

-Autoenginuity w/Ford bundle on laptop
-Yes, no codes
-ICP was from scan tool (I looked at voltage, but do not recall what it was)
-IPR screen was/is not broken, just had what looked like very small carbon bits (think: grains of sand size and smaller)
-RPM: cranks as fast as a normal start would have. The last time the truck ran, it idled VERY slow; slightly faster than cranking
-Dealer also said one inector was bad, but would not tell me which one.
-Glow plugs ohm out fine
-Buss bars pull around 28DCA each during glow plug warming (if memory serves me)
-Checked recent datalogs from just before it quit, ICP voltage was as low as 0.75V and as high as 1.99V. It appears I only saved one session from since it will not start; ICP voltage claims to be 0.97V.
-Resivor screen for HP pump, does that not screen/filter the oil before it goes into the pump? How could debris there point to a bad HP pump; would not the engine oil filter catch most debris before it reaches there?
-Injectors passed the 'click test' in the scan tool, last time the truck ran.

 

[platinum01]

Sorry to High Jack your thread here but that is an awesome lift platform you have there. How hard is it to remove the cab from the frame? Hope you get your problems fixed.

 

[Jetpilot1]

Eubee

ICPv needs to be .8 -1.0 vdc during cranking minimum to fire the injectors. Normally it will read around 1.5v.

Anytime the IPR screen is broken, you have to go downstream to the reservoir screen in the oil cooler, but it sounds like the IPR screen is intact, but with metal bits (HP pump?)

Total glow plug draw is high - around 180 amps as a set.

ICPv .75 is about 450 psi, 1.99v is about 1500psi.

That debris on the IPR is troubling, one of my manuals says if there is debris on the ipr when it is removed, replace the hp pump. Pump failures are relatively common. I'd go out with the scantool and crank her up and watch the ICPv see if it gets to 1.5 or at least .8 during crank. If you don't get that minimum, with the debris on the IPR, I'd suggest your hp pump is gone.

 

[Eubee]

...

Yeah, I hear the pumps are a common replacement; I was just hoping that my problem was something else. I will have to put some of it back together in order to crank it and get oil flow. I guess it is time to get back to it.

I'll report back with what I find.

 

[Eubee]

Hmm, I can not hook up the scantool without the cab set back down on the truck. I guess I will have to put in a mechanical gauge and check actual pressure. How easy are high pressue oil gauges to locate for purchase? Will that even work the way I am thinking?

Thnx

 

[Eubee]

Well, I got an itch to disassemble the HP pump today. There is some light internal damage. There is a small chunk of aluminium missing from the oil's pathways inside the housing and it looks as if that/those piece(s) got lodged between the side of the housing and the swashplate causing the piece(s) to grind and melt into the housing. I am trying to get some pictures to show what I am talking about, but the lighting is not working with my phone's camera; hopefully natural daylight in the morning will solve that. The damage looks small, but if a bad o-ring can cause a truck not to start, this damage could cause enough of a pressure drop to do the same.