New thought. It’s only at idle and only occasionally, and when warm is the time. I had this issue before the rebuild but I chalked it up to a ICP giving me fits.

I did me the bubble test no problems there, what are the chances of two bad motor craft injectors?? Slim to none I feel like out of the box.

im wondering if I don’t have a stupid oil rail check valve issue. My symptoms match others. It’s really got me thinking ……

 

Earlier I did get it to act up in the driveway once and set the code. The engine was running smooth in park, soon as I put it into R and loaded it against the torque converter I felt the little stumble. Not a complete misfire like when I disable #4 but it’s like a little more vibration like it’s not firing correctly. I couldn’t replicate it but this one time.

Cleared all my codes, went on a 5 mile test drive, did some pulls, monitored data, nothing wacky. Engine is idling smooth as can be. No code this time. I suspect this P0272 maybe coming back hard to say. No white smoke at idle.

Ficm?
Injector?
oil rail check valve?
mechanical engine issue?

I didn’t see this issue on the tow tune. It commands about ~1000 psi at idle. Maybe the injector on #4 is not happy at 640 psi? Makes me wonder…. #6 did not come back. Maybe it was a fluke or a miscalculation by the PCM.

 

After more than 200mls there should be no more air in the system. If the injectors are from a Ford dealership, you should be able to assume good quality.
You should check the cylinder balance with IDS, here you can see pretty much the problem.
In this video you see a dead No.5, No.2 and No.7 are also not optimal, but do not throw codes yet.
Do you have the possibility to exchange your FICM for a knowing good one? Otherwise, the only option would be to swap the injectors with each other to see if the error migrates. And let the EGR valve plugged in.

 

No IDS but I would love a clone. I would probably have to purchase a new FICM. I have a new Ford harness and ficm harness. Buzz test all happy. I can only do limited stuff with Forscan. The more I think about this issue the more I remember it doing very similar stuff before. The common parts to the problem are : PCM, Ficm, and oil rails. The rest of the crap has been replaced during my rebuild.

I have a suspicion it’s these oil check valves on the 03/04 log rails. Gosh I wish I would have checked them out more during the nipple cup seal replacement.

 

With 1000psi oil pressure in idle, I don't think the issue is oil / oil side related.
I'm seing 580-600 psi.

 

it runs 640 on stock tune and 1000 on the custom tune. No oil leaks and my truck hot starts fast.

this is what I’m thinking, it’s an 03/04 issue. There is a check valve of sorts on the oil rail quick connect fitting. It somehow becomes restrictive and chokes off the oil pressure at idle to the injectors. Causes almost phantom contribution codes. I did a bunch of research and my symptoms are very similar. It’s not a full misfire but it’s like a partial. Injectors 4 and 6 are next to each other. I’m willing to take the gamble and try to replace the one on drivers side. There is a TSB about this weird issue.

TSB 082001

https://www.ford-trucks.com/forums/1...ck-valves.html

 

I'm not sure if you're referring to my comments but if you read them, I think you'll see that I typed that I didn't remember "the exact specs" if your comment was referring to mine. Also, you've been a member of this group (and I'm sure others) for probably a few decades so even you should know that there are all kinds of numbers thrown around. Some may call them "specs" while others may consider them "generally accepted" baselines to work from even though they are obviously different things. The latter would be more problematic wouldn't it? Except that some people have decided that the manufacturer's specs aren't what someone should follow for what to use for diagnosis or running values and so on. (See the endless posts about what to do for the 6.0 and other vehicles that deviates from the manufacturer's recommendations or actual specs.) I could take some time to look up some various posts but I doubt I should have to. I'm not saying it's okay or right but I'm just saying that I've seen all kinds of numbers for the fuel pressure values over the years. And not that this is the exact same thing but since fuel pressure is related to fuel injectors, I've seen people say to "never go below x" while others say "never go below y" and 100 different variations. In any case, I don't recall seeing that anything in the 70s was okay. At least not for a "semi stock" build which I will assume this is considered.

 

I copied the text below from the referenced TSB 08-20-01 (sorry for the text size on the headings):
.
.

ERRATIC HIGH PRESSURE OIL SUPPLY

Erratic supply of high pressure oil to injectors may cause a rough running engine. High pressure oil flow can be disrupted by faulty check valve(s) or a faulty injection pressure regulator (IPR) valve.

To diagnose, first perform a slow neutral run up in park / neutral. If the engine runs rough between 1200 and 2300 RPM proceed to Check Valve Diagnosis; if the engine runs rough between 3000 and 4000 RPM, perform PC/ED pinpoint test Q, if the engine continues to run rough between 3000 and 4000 RPM after having validated the ICP sensor and connector, then replace the IPR valve.

Check Valve Diagnosis

1. To isolate the bank with the faulty check valve, disconnect all of the injector electrical connectors on one bank.
2. Perform a Power Balance test. Engine misfires should be constant on the four disconnected cylinders and the operational cylinders should be contributing evenly.
3. Repeat Steps 1 and 2 on the opposite bank.
4. If the operating contribution is erratic on one bank, replace the check valve on that bank.

 

Blicharski1989,
Did you ever get your fuel pressure issue resolved for sure that you were having previously?

This post:
https://www.ford-trucks.com/forums/1...osis-help.html

Is it possible this has anything to do with what's going on now or what contributed to what led up to this whole $9k engine rebuild situation? Perhaps it isn't but I would hate to think that it could have something to do with any or most of this.

 

Back to editing my ignore list.

 

yes it’s fixed and no it’s very unlikely my low pressure at WOT caused my 250,000 mile head gasket failure. Your quite the detective.

 

I’ll need to get IDS for this test. I’m skeptical of the engine running on 4 cylinders but maybe I’m wrong.

have you ever seen this oil rail check valve issue before on an 2003?

I can see if I can get an injector warrantied. Try that and the new check valve. That’s about all I got. Connections are solid. Fuel pressure is good. ICP/IPR are good.

Going to switch my tune back to the tow tune and see if the code goes away. It set the code again this morning within a few minutes of idling.

 

I have never seen it and have only heard of it a few times. From what I recall it very well could have only been 03 engines.

 

gotcha that’s what I figured. It’s the only real link between before and now.

going to change oil to motorcraft today.

I called ford $165 diagnostic fee. I may take them up on that. It would be good to measure base engine compression, power balance, and whatever else they want to do.

at this point, it’s either bad out of the box injector, injector got some crud in it, or that stupid check valve, or an unlikely base engine problem

 

Well the codes are gone for now no more intermittent contribution codes.

total miles on truck ~400

changes: 13 quarts motorcraft 15w-40 and 2 quarts of hotshots stiction eliminator, and a motorcraft oil filter. Changed back from stock to the street tune from blessed performance. Whats crazy is this more aggressive tune is actually running lower EGT than my tow tune which is supposed to be fairly mild. Maybe it’s a difference in injection timing? Maybe cylinder 4 and 6 spool valves were hanging up causing delayed injection?

it’s idling smooth as silk. 640 rpm +- 5 rpm. Call me crazy but the exhaust smells less “diesely”. There was never white smoke when warmed up but it seemed to have a less strong exhaust smell before I rebuilt it. Oil change and 15 mile drive and I can tell a difference. The engine is idling significantly quieter also. Goes without saying these HEUI oil systems are very sensitive to fluids. Maybe I had some gunk in the oil rails? Maybe there was some gunk in the engine?

I talked with the guy that sold me the injectors he will warranty them through Ford for me. I just want to be sure we’re not doing the parts throwing dance. I did order one of those check valves for the oil rail. I’d like to swap that out because it just involves removing the valve cover.

to be determined, sea trails take 3……….