It's time to address this issue head on. Here's where we stand.

A while back I posted an issue with no start hot we thought was ICP Sensor. Nope

Rebuilt IPR and swapped with known good IPR. No change

Looked into AE and ended up purchasing Monday after Easter. Great buy. I enrolled in Dr. Tugly's class and I think I'm getting a B, maybe B+. I've learned more about the 7.3 then I thought I ever would all because I understand, somewhat, what you guys are talking about now.

Diagnosed a few issues; EBP Sensor and pipe, Map sensor, Low fuel pressure, learned about how the IPR works, etc... I've even taken a few diagnostic roadies with the laptop. Eye opening stuff.

My son has been driving the truck (when I'm not fiddling with it) and just plans out his stops carefully. Up until today, that has not been a problem. Temps in the Central Valley of Ca have gone up big time and so has the operating temp of the 7.3 and the OIL TEMP.

Here's where I am today. Fuel-good, air-good, no apparent electrical issues.

COLD - IPR pressure is good and duty cycle seems good (48-50% WOT). Idles smooth

HOT - IPR pressure seems good idle to WOT. Duty Cycle changes as oil warms (67% WOT). Idles rough.

After reading and studying for what seems like days, this appears to be a classic injector o-ring issue. Purchased new, this truck has 260K on it and the motor has never been opened. It's been well maintained and has never missed it's regular oil change with Delo 15W-40 and Motorcraft filter, 3000 miles when on the ranch, 4000 miles when on the highway. (ranch life requires more frequent maintenance). Only chronic issue is a leak at the rear of the pan. Original transmission with John Wood valve body.

Am I headed in the right direction? Do I have all the info needed to make a good decision?

You guys have already been a huge source of information, help and encouragement. I thank you all in advance.

 

Oh my gawd... I can teach? Very astute observations there. Isn't it nice when you feel the light bulb go on? You just reach a point where you say "I get it!"

I'll explain for those who feel like reading - like maybe they're on the toilet... with their phone or tablet.

As sportsdad has learned - the High Pressure Oil Pump (HPOP) must maintain a minimum pressure - or the truck will not start, can run rough, or stall. Oil pushes the fuel out of the injector like a your hand pushes Windex out a spray bottle, so you don't want a weak hand (High Pressure Oil - HPO).

sportsdad was watching the command to the Injector Pressure Regulator (IPR), this is what regulates the pressure out of the HPOP, and he was watching his Injector Control Pressure (ICP) - that last part is the sensor that reads how high the HPO pressure is. If the pressure is low, the IPR command goes higher to compensate. 9% to 14% IPR (475 to 700 PSI ICP) is normal for idle, depending on engine temperature and idle RPMs. 37% to 43% IPR (2400 to 2800 PSI ICP) is normal for Wide Open Throttle (WOT) - that's your right foot reaching for the ground like Fred Flintstone.

About 65% IPR is maximum the stock truck programming will allow (to attain that 2400 to 2800 PSI ICP). The thinking was if you can't get enough pressure with 65% IPR, the other 35% isn't going to get you there either - plus you have a new problem if you go to 100% IPR: The IPR is very slow to react, so once the demand for HPO drops sharply (you let off the testostopedal) - the IPR is jacked up too high to properly compensate for the radical change in oil demand. A throttle let-up will then lead to a huge spike in ICP (well over 3000 PSI ICP), and that's hard on the ware. I call this ICP spike a "Stinky Spike", because I first learned of how this happens on Stinky - the wonder truck.

Once the IPR goes over 50%, you must learn the root cause of the anemic ICP... because this means your High Pressure Oil System has a problem somewhere. It could be a sham (maybe the ICP sensor is lying), a weak HPOP, a control problem (bad IPR), high oil demand (an internal oil leak or a flaw in the non-stock tuning), or air in the oil (weak Low Pressure Oil Pump feeding the HPOP or some other delivery problem).

Speaking to High Pressure Oil issues in 2014 (not 2003) - the most widespread cause of the above on a tuned truck is excessive Fuel Injector Pulse Width. IPR and ICP hardware failure is common on all trucks, aftermarket-tuned or not. After those easy ones, things get a little more "wrenchy" and/or pricey. Bad O-rings on the IPR or HPOP lines can cause leaks, driving the ICP down and the IPR up. Bad injector O-rings is becoming more common with the calendar and odo flipping.

After you've tried to wrench and O-ring your way out of runaway IPR (to no avail), your Buck$Zooka is trembling with anticipation at the opportunity to come out and play. This is when you click that Injector Troubleshooting link in my signature, or start eyeing that T500 HPOP you've always heard about. If your injectors have a lot of miles or a lot of neglect (poor oil or fuel maintenance habits)... these are the prime suspects.

LPOP failure is very rare (to date). HPOP failure is less rare, but still rare. That being said, most people that have updated to a new stock HPOP see at least a small bump in performance, and upgrading to a T500 or the like has made at least a big improvement in ICP at WOT (not necessarily a total fix) - so weak HPOPs are not uncommon. Injector failure in 2014 is very common - just try to find a good injector rebuilder who isn't overloaded with orders, and that's all the verification you need.

Overloaded injector rebuilders - that's a whole other issue. These guys with fantastic reputations in years past are taking a beating now. They have to get so many sticks out per week, that the rebuild and test process is getting rushed... leading to an increase in failed rebuilds. Even with proper rebuilding procedures, the inventory of used cores has more wear on them than they did 5 years ago... so the base stock grows ever-more "contaminated". Even if you go modified-new, the overload-work problem still exists - so be prepared to have at least one stick act up in some way. I've had two modified-new injectors go off-balance or crazy loud within 5000 miles after install, and I know of other members that had similar occurrences.

 

Yes Rich, you can teach. My AE learning curve was pretty shallow at first, but it increased once I married the truck and the computer. Words on a page tend to be theory until applied to what you're dealing with. This is an education I would suggest to any Powerstroke owner.

Now here's the next question, do I pull all the injectors and check cups and replace o rings while I'm in there or just search for the offending one? Remember, 260,000 miles and never been opened. OR, do I pull the motor and spin it and do the pan too? (But my trans has 260K also and may need help in the future which would be a good time to pull the motor).......

Can you tell that I'm a little conflicted about this whole thing?

 

Are you using oil? If you've got bad injector o-rings, you'll either be using oil from the leak, or it will be bubbling up from the base of the injector enough that you can see it with the valve cover removed.

 

I'm not losing oil externally. I don't have oil in my fuel. I do have an oil pan leak so I can't measure oil loss/consumption.

I have yet to remove a valve cover to see a leak. I hope I find a gusher and it's that easy. My concern is, after 260,000 miles, should I just do them all?

 

This problem sounds like it could be your engine oil temperature sensor. Swap yours out with a known good one (if you know someone who could help you out with this) and see if that resolves your problem.

 

Please explain Cutlass. In researching this issue, this is the first I've heard of the EOT sensor being an issue related to no start when warm.

 

Bump. Gotta get back to the first page

 

I too am curious what Cutlass has to say here.

 

If you have the means to pull the motor, I'd hold off until you know what the problem is. Once you pull the motor and do repairs, you have no idea how successful you were until the engine is back in. If you know you have a major issue that's easier to address on the stand (in addition to the oil pan), then this urges the decision along. Injectors or injector O-rings? Truck. Cups, springs, and intake manifold? Stand.

If this were Stinky - when doing O-rings, go big. Inspect everything - coolant pressure test, compression test, cup test (no coolant in motor, use air and spray cups with silicone spray lube). The more you know about what's going on with the truck, the better your future decisions will be.

I have done all of the above, and while time-consuming - it's worth it for piece of mind (or sleepless nights if you have bad news).

 

Sounds like sound advice Rich. I have watched a couple of videos about pulling valve covers and injectors and that doesn't look too tough. I just don't like doing things twice or 7 times. I read your lose injector thread, ouch. I'll start checking out these tests you recommend and drag out the compression and coolant system test equipment.

 

AMEN and for good reasons!!!! At some point you have to say no I can't make that dead line.

 

Back to the problem. I finally got some time to work on this issue with no start hot.

Did a warm compression test. I'm very pleased with the results. Low of 410 on #1 and High of 425 on #6 all others are 420. Leaves me feeling good about doing anything I need to do to this motor.

Pulled the injectors. I hoped to find a gusher, but instead found 8 beautiful injectors with no obvious problems. All 8 cups look perfect from above with no cleaning yet.

I guess next will be a pressure test on the coolant system.

Questions: REMEMBER 260,000 miles

1. What do I do with these injectors. Would entertain the idea of stage 1s, but I'm in Cali and can't forget about the snap (smoke) test.

2. With no obvious broken O'Rings, where am I loosing my oil pressure when hot? I guess it could be the hpop.

 

Internals on old injectors can bleed oil pressure as well. Many people swap injectors and see their ICP rise and IPR fall, but I can't swear to the effectiveness of new sticks from my position - many miles from your truck.