Is there anything I should be checking?

 

Check fuel pressure. Check ICP pressure and duty cycle while cranking and under load.

Need a scan tool to do the ICP and duty cycles.

 

Ok, just got done doing some testing.

IRP Duty Cycle: 34% Cranking, 9% Cold Idle, 11% Hot Idle, as high as 65% WOT under load

ICP Pressure: 475-525 PSI Cranking, 475-600 PSI Idle, 2450 PSI first WOT run, 1550 PSI
second run(MIL) came on. Both WOT runs, IPR was between 60-65%

Fuel Pressue: KOEO and Idling 57 PSI, Revving in neutral, stays above 55 PSI

Watching the ICP at idle, was around 500-525 PSI, Kill the engine and watching the pressure bleed down, it takes around 5-10 seconds to get to 0 PSI. IPR stays at 15%. Is that normal?

I'm running Rotella T6 Synthetic 5W-40, have been for past 70,000 miles. Right now there is no smoking from the engine at start up or wide open throttle. In colder weather, truck always has blown some white smoke for first 10-15 secs on cold starts. Gets worse as temp drops.

 

Just did a little more testing. Truck runs best before it gets up to temp. On a short drive, WOT, the IRP will be up around 50%, ICP will be around 2400 PSI and the Fuel Pressure will stay at 55 PSI. As the truck get to normal operating temp, doing another WOT run, the ICP will struggle to reach 1400 PSI while the fuel pressure and IRP remain the same. Could this be an oil issue? The oil has 100 miles on it. I changed the oil and filter along with the fuel filter right before this trip. Issues started around 60 miles into the trip.

 

Bump

 

Just took the truck for a spin. First start of the day, Starts instantly. HPOP can reach over 3000PSI. As the truck gets warmer, the HPOP pressures decrease and the crank times increase. The scanner shows the IRP % spot on, does that mean it is working or is the scanner just showing what the computer is calling for and the IRP could still be off?

I hate to start throwing parts at this. I need to figure it out before out next camping trip in early July.

Any help would be appreciated!

 

Why are you running 5w-40? That oil is too thin. As oil temps increase, you lose pressure. Go back to 15-40, as Ford recommends.

Have you monitored oil temps?

 

Watched the oil temps today. Everything is good till about 110 degrees. From there, as the temp increases, the pressure decreases. Same goes with cranking time, hotter the oil, the longer the crank. I haven't had the chance to change to 15W-40 but I believe there is a problem elsewhere. I will switch to the 15W-40 but I need to figure out the pressure loss and it might be easier to do with the thinner oil.

 

I was told to run that from the prior owner for the winter months. Never put enough miles on it to justify changing out in the spring. I've been running and towing without issues for past 5 years. I'll change out to the 15W-40 but why would it have been fine before? I haven't monitored oil temps yet but will try check that out tonight and post the results. Thanks for the response.

 

As Joey stated, thicken up the oil and see what happens.

Your IPR duty cycle is way too high(65% is max). I think your issue is going to lie within the IPR or the HPOP itself.

When you are monitoring IPR duty cycle, you are seeing what duty cycle the PCM is commanding, not the actual position of the valve.

 

Try unplugging your ICP sensor and see if the duty cycles stay the same.

Sounds to me like an injector issue. As the oil heats it slips past the injector clearances... Going with a heavier oil is a bandaid to an injector issue. You could run what ever weight oil you wanted, and it will run fine so long as the injectors are healthy.

 

I checked the IPR solenoid nut today, it was snug. I have a IPR rebuild kit coming tomorrow and will clean and try that since its quick and easy. If no luck with that, I'll look into the fittings for a block off.

 

Change the oil... Its not your issue, but the oil nuts will go away. You have an injector issue.

 

Care to elaborate? Do I need new injectors or is there a seal or o-ring kit for the injectors? The oil change will happen, just dont want to mask the problem and then have it reappear when I'm towing the camper with the family.

 

It could be as simple as a set of injector O rings, but I would bet you have internal injector issues on the oil side.

 

agree oil pump will cause this an its more likely to be your IDM inside your drive fender that is where ive been an fix my prob on 2001 2003 my 1997 or 1999 not probs

 

WHAT?

I have no idea what your trying to get across here... This is not an IDM issue.

7.3l are known for injector cups to leak. make sure no coolant or fuel is in your oil also

No, there not known for injector cups to leak. And its not an injector cup issue...

 

I am having a similar issue with my truck. Starts right up cold and takes 10 or more cranks to start when it's shut off at running temperature. My injectors are only a year old. I have installed a new IPR and it hepled some ,but did not cure my hard start completely. I had been running Rotella 15/40 and the truck started great all the time. I recently switched to Shafer's synthetic oil and that is when my truck started the hard starts when warm. I have not switched back to Rotella yet to see if it starts any different. I just figured my HPOP is getting weak. Putting mine on a buddies scanner this weekend to get some readings.

 

Any updates on your truck?

 

Rebuilt the IPR lastnight. No change at all. Will be going back to conventional 15W-40 tonight to see if that helps. I would like to do the block off test but I dont have the fittings needed nor the time to source them. Will post the results of the 15W-40.

 

Just dumped my 100 mile old Rotella T6 5W-40 for 15W-40.... Results are same if not worse. With oil temps above 150, the IPR reads 65% at WOT and the ICP fights to reach 1500 PSI.

 

I've got a Snap-On Solus Pro scanner. Is there anything else I should be looking at to figure this out? If I had a leaking injector, would it show anywhere? It passes buzz tests and cylinder contribution tests, there is no smoking and the engine runs smooth at all times hot or cold. I'm leaning towards the HPOP. I'm gonna have to get a block off set up figured out so I can verify. Everything gets expensive at this point so I don't want to guess.

 

The 15W-40 non synthetic is also causing the romps on cold start. Ambient temps in the mid 70's. Does that indicate anything?

 

If it was an injector bleeding off the pressure, would that cylinder show any effect? Rough running, smoking?

 

I made my own block off tool this morning and did some testing. With the right bank blocked, She started after a few extra cranks than normal, the IPR was jumping between 28-45%. Tried the other bank and got the exact same results. In the tech spec sheet, it says the IPR should be down around 16%. I dead headed the pump, The IPR reached 65% and the pressure only built up to 1450 PSI. At 65% the IPR is maxed out and a dead headed pump should reach near 3000 PSI right? I'll try the new IPR tomorrow with it dead headed and go from there.

 

Ok, looks to be the HPOP. New IPR this morning, with the HPOP dead headed. Cranked it over for about 15 seconds, the PSI reached 1800 with the IPR at 65%. With the IPR at 65% the pump should be able to reach 3000PSI when it is dead headed right?

 

Sounds like the pump is your issue...

I knew it was not oil related, but some people get all caught up on oil...

 

Removed the fuel bowl and HPOP, The screen to the HPOP had some crud in it. Any thoughts on this? I had a turbo go out on me last year, I'm assuming thats where the metal and crud came from. First time the engine has been apart in 176,000 miles. Is it normal to find some stuff on the screen. Here's a picture.