Dear me.. Won't start after HPOP fitting....

[hardhatz]

I am thoroughly stumped here, gentlemen.

My 07 got hard to start when hot. After some research I checked the HPOP connector & it was bad. Changed it out, put it back together, now it won't start. Cranks well. No codes thrown.

Something strange I noticed is that it shows normal oil pressure as soon as you turn the key on, even when it is not turning over.

Any ideas, Wizards?

[flatbedin]

Which fitting did you replace? I am assuming the STC, but you know what you do when you assume.. Are you reading your oil pressure on a scan tool/manual gauge, or the dummy gauge inside the truck. Because I believe the gauge inside the truck will show pressure on it with as little as 7.5 psi if I remember correctly.

[hardhatz]

Yes, the STC fitting between the HPOP & the branch.

Yeah, I read that the gauge really is a dummy, showing normal if there is any pressure at all. How stupid... In my case, it shows normal as soon as you turn the key on.

Has anybody tried bleeding the HP oil circuit by taking out the ICP sensor & cranking it over? Also, I read that the IPR valve dumps when de-powered.. would unplugging it be a good way to bleed it?

[flatbedin]

Any air trapped in the system will work itself out. It may take a minute or two, but it will work itself out. I would either put a manual gauge, or scanner on it and see exactly what type of oil pressure you have.

[hardhatz]

OK, it's getting worse..

I pulled the turbo so I could check the IPC & then I took out the IPS & cranked it about a minute total until I got oil out the port, then I was finally able to get it fired up using starting fluid. It took about 10 seconds of running to get oil out of the turbo supply line. The sound of it out the Y pipe was fabulous!

I shut it down & reinstalled the turbo and it started ok, so I shut it off & buttoned everything up & topped the coolant. I put everything else together & suddenly it refused to start without ether. Even after running it an hour, it will not re-start without starting fluid.

It will idle ok. If I try to hold it around 1000 RPM, it surges from 500 to 1500 just like you were flooring the pedal 2 times a second. It is also rough above 2000.

It now throws codes 336 & 683.

It also now makes a big screeching noise when you floor it hard.

If I plug a pressure gauge into the IPS port, will it give me an accurate cranking pressure?

[flatbedin]

You can go to a local hydraulic shop and get a adaptor and hose and manual gauge to screw into the ICP sensor port (the sensor on the passenger valve cover at the front) and this will give you your cranking psi.

You need a min of 500 psi to start, and from the sounds of it, once started, it's loosing oil pressure to the hpop. Either due to a leak, or your low oil pump is starving the hpop.

[Csolomon]

Originally Posted by hardhatz

OK, it's getting worse..

I pulled the turbo so I could check the IPC & then I took out the IPS & cranked it about a minute total until I got oil out the port, then I was finally able to get it fired up using starting fluid. It took about 10 seconds of running to get oil out of the turbo supply line. The sound of it out the Y pipe was fabulous!

I shut it down & reinstalled the turbo and it started ok, so I shut it off & buttoned everything up & topped the coolant. I put everything else together & suddenly it refused to start without ether. Even after running it an hour, it will not re-start without starting fluid.

It will idle ok. If I try to hold it around 1000 RPM, it surges from 500 to 1500 just like you were flooring the pedal 2 times a second. It is also rough above 2000.

It now throws codes 336 & 683.

It also now makes a big screeching noise when you floor it hard.

If I plug a pressure gauge into the IPS port, will it give me an accurate cranking pressure?

[WEWILLE]

What kind of scanner do you have?

[hardhatz]

Not sure.. Orange, I know that. I also have an SCT that scans, maybe I should try it...
Prolly should clarify my "starting fluid" penetrating oil & propane, and just enough to keep it ticking over maybe 3-400 rpm. I disconnected the glows.

[m-chan68]

This is going to sound like a stupid question. Were you actually able to get the truck to fire up and run, after the repair? If so, how long did you actually let it run for? Typically, after any repair that requires opening up of the high pressure oil system in any way (ie injector(s), high pressure oil rail(s), standpipe(s), and /or the pump itself), much longer initial engine crank time is to be expected. And in answer to your question, NO the high pressure oil system does NOT require bleeding in the sense that you are thinking of. What I usually do after any extensive repair, is I start the engine and run it at FULL THROTTLE (foot to the floor), until operating temperature is reached. At this point, is where I would road test the vehicle for a few miles in order to keep the system primed. And no, revving the engine at 3800 RPMs is NOT bad for the engine, in case any of you are wondering. Remember, these engines are GOVERNED, which means you can't blow it up.

What you need to do, is monitor ICP volts, ICP psi and IPR % on your scan tool. You need to monitor those three pieces of info, at key-on/engine-off, while cranking the engine, and at key-on/engine-running (when at operating temperature, if you manage to get the engine started).

Ignore your P0336 and P0683 DTCs. Those were probably set when you disconnected the glow plug control module.