How and where to check for fuel and oil pressures

[navajochief]

I currently have a no start issue and have went through the process of replacing glow plugs, fuel filters, glow plug control module, glow plug harnesses, belts, belt tensioner, camshaft and crankshaft sensors. I have a feeling it may be the dreaded high oil pressure pump but I need to know where and how measure pressures for the high oil pressure pump. I also want to know where to check for fuel pressures. What are the specs for both? What are the parameters for both? I know a lot questions. I may have to replace the high oil pressure pump and if so, is it difficult? Back story to start. The engine will crank but won't come on. Thank you in advance for any assistance in this matter.

[bpounds]

Since you have an '05, it is a good bet that you have a high pressure oil leak, probably at the STC fitting on the HPOP. Here are some DIY things to try.

First, you need a minimum of 500 PSI of oil pressure (ICP) for the PCM to fire the injectors. You can have the DTC's checked to see if that is the problem. This particular issue won't set the CEL, so you have to have the codes checked.

If you get a low ICP code, it could be a bad ICP sensor, if you are very lucky. To check that, just pull the connector off of the ICP sensor, which will cause the PCM to use a default value, and the engine should start IF there is actually enough ICP. If it starts rough, or trys to start but not quite, then don't run the engine because the ICP is probably marginally low and you can damage the injectors. If it starts and runs good, then it was probably just a sensor.

The next thing you can do is to actually check the ICP by reading the voltage from the ICP sensor. To do that, tap the DarkBlue/Light Green wire and the Gray/Red wire and check the voltage while someone cranks the engine. You need at least 0.8 volts, which represents 500 PSI. If you get a voltage, but it is not at least 0.8 volts, then assume you are leaking high pressure oil as I guessed at the top. If you don't get ANY voltage, check fuses.

These are things that I could do on the side of the road. That's about as deep as I could go, and then off to the dealer. The STC fitting requires R&R of the HPOP. I doubt if you actually have a failed HPOP, but anything is possible.

[2 Stroker]

Well i will take the fuel pressure
If you get a fuel pressure gauge and your pressure is low this is the fix.


Mine before i installed the fuel pressure gauge i had 50 lbs at idle and 44 at WOT and that is to low, installed the kit now 62 idle and 58 WOT, low fuel pressure will kill injectors and over 70 lbs may blow injector o-rings.


The Reg. Kit number is 3C3Z-9T517-AG and you get it form Ford
The spring is located behind the small plate that the return line attaches to. This is probably one of the easiest repairs you can make... Take the four screws loose (they are T-27 torx screws), change pull the old spring out of the brass cup, put the new spring in and re-install the plate. When you are taking it loose, keep your thumb on the plate so the spring/cup doesn't pop out and also use your thumb to hold the plate up tight to the fuel bowl when re-installing, so the screws can be threaded in good. If you buy the whole kit (which I think is the only way you can get it from Ford), I would replace the brass cup while you are at it..
You can see the plate and return line here.
Page 30: Fuel Supply System

I would not buy the aftermarket spring from GDS. It has been shown to raise pressure well beyond what is recommended and risks blowing the internal o-ring in your injectors
The only hard part is the hose is in the way, you need to get a turkey baster a new one and suck out all the fuel from the upper filter houseing that way you don't have a mess. After you are done you have to cycle the key 3 time 30 sec. each time to prime the fuel system.
Here you go this is a good post by Band Member on the fuel pressure reg spring install over at the Dieselstop.
Fuel Regulator Upgrade w/ Pictures - Diesel Forum - TheDieselStop.com
2 stroker

[RNUOVR3]

very interesting reading.

[bpounds]

Good info 2stroker, on the fuel spring update. But while that is a good upgrade to your truck, it doesn't have anything to do with the OP and his no-start issue. Slightly low fuel pressure won't cause this issue, but NO fuel pressure certainly would. All he needs to do to eliminate that possibility is to pull the cap off of the upper fuel filter, and have someone turn the key on. When the fuel gushes out you will know your fuel pump is working.

[2 Stroker]

bpounds i understand that BUT here is part of his question
want to know where to check for fuel pressures. What are the specs for both? What are the parameters for both?
2 stroker

[navajochief]

Fuel pump has been ruled out as cause of "no start." We tapped into the STC fittings and attempted to read pressures from the HPOP as the engine cranked. No pressure. Not even 100 psi. My question now is, if the HPOP requires replacement, does a new HPOP come with a kit that will include gaskets and all the "bells and whistles" needed to replace the HPOP. I'm assuming the turbo will have to come off as well as the EGR so will I have to purchase o-rings when reinstalling the turbo back to the housing and the like? Also, to rule out the low pressure oil pump, can I simply remove my oil filter and allow the oil to drain into the pan and with the oil filter removed, reach in and press the latch down and as the engine is cranking, check to see oil is filling the chamber where the oil filer would sit. I guess to make a long story short, what else would I have to purchase since I'm replacing the HPOP in order to maintain the integrity of the parts that have to be removed during installation?

Thank you.

[domesticdiesel]

HPOP comes with gaskets and new style sct installed. However HPOP is one the most mis diagnosed parts on 05-07 trucks. PM me with all the diagnostics steps you have done so far so I can try and help you.