what about the screens in the tank? i was noticing the same thing in my truck yet no codes set. i would get a rare 1211 code when i was "goofing off" on back roads near the farm.

my truck just seemed sluggish.

although it towed my dakota on a trailer just fine through the hills from freemont to sacramento last year.

i dropped the tank and cleaned the screens- now it's a new truck


p.s. it only did it (p1211) when tuned- not in stock mode.

 

Injector O-rings can also be a cause. I'm just going to go with single shots in the spring of next year.

 

Agreed. Especially with a T-500 added, and it still can't keep up. Single shots or hybrids would be the way to go in my opinion.

 

I've got a new ICP, IPR and HPOP (stock) in the last year. My truck throws a P1211 under heavy loads pulling our fiver all the time.

It'll do it in stock tune or the 20T that I usually run in. Power is all there, mileage is good (10 or so towing, 15-18 otherwise), no more black smoke than I would expect under heavy loads. It'll pull 23 psi of boost easily and never really falls flat on its face.

No evidence of bad injector o-rings. I have no clue. I just get used to the CEL coming on during long, hard pulls and use my AE occasionally to make sure nothing else is being added to the mix.

 

Today, I took the truck to an injector shop. They had no clue either. It showed a number 8 injector problem, but they told me that is common and they would not spend the money to look at it.

They agreed there 'may' be bad injector O rings. But they didn't sound too convinced. They also noted my IPR was shooting up to 70-80 and it was way too high.

I mentioned the dirty gas filters and they told me that is unlikely. Other diesel mechanics have suggested I add a quart of ATF for the next few tank fills to clean the screens (and have new fuel filters on hand) because of the detergent effects of ATF.

I'm planning to pull my valve covers this weekend and see if I see any leaking injectors.... My buzz test and cylinder contribution tests seemed find (except what I mentioned earlier).

Oh yeah, I almost forgot. The injector guys theorized I may have a low pressure oil pump that has too big of clearance and is just not keeping the HPOP reservoir full. They suggested a guage to watch it right where you fill the HPOP reservoir. I'll probably throw one on to check it...

 

A good indicator of bad injector o-rings is when under a load, does the ICP drop while the IPR% goes up? I guess it is possible the LPOP is bad, but it's something I'm not familiar with. A T-500 should hold the ICP you need assuming the o-rings are good. I remember a year or so ago on a different diesel website, Bill from PHP and Dave from Swamps got into a good discussion about the relationship of IPR, ICP, tuning, o-rings, and such. It was very educational. I'll see if I can find it.

 

Found it,
The relation between Injection Pulsewidth and Loss of ICP - PowerStrokeNation : Ford Powerstroke Diesel Forum

 

Look at your Fuel Injector Pulse Width. If it goes over 3ms, ICP will tank.

*EDIT* I no sooner hit "Submit" and I see CampSpringsJohn beat me to it by about a minute.

 

OK... I breezed through the link that CampSpringsJohn provided and I saw a lot of blurry images of an oscilloscope, plus a lot of text making a case on the effects of FIPW on ICP. I have something here that doesn't require a lot of explanation (for those who can decipher graphs). This was a stock truck with a tuner towing a load up a steep grade and backing off the fuel every time the EGTs spiked. I think the thing that's also noteworthy is the high EGTs coincided with the high FIPW. Make careful note of the IPR trend in relationship to the FIPW.

 

After studying that graph for a couple minutes, I understand it!! (I'm not my parents smartest child!!) As Pulse Width spikes, ICP drops, but EGT's spike too. So, is it possible the fuel is being delivered under too low pressure causing an uneven burn and spiking the EGT's? Is that what I'm looking at?

 

Yup. Low ICP = slow fuel delivery (and lower atomization) = long burn = high EGTs. I've known this for a while (the root reason for going to AC160/100 injectors), but this data hit my email last month and I've been debating on posting it. This can lead to people seeing a PW spike and assuming the tuner is to blame, but there are many causes for a PW to go runaway. If everything in the truck is 100% and you still get PW spikes, only then can you really suspect the tuner. Does any of this sound familiar?

 

Yes. I must admit, reading that thread from over a year ago, a lot of it was over my head, but I tried to understand it the best I could. I guess I'm a year older, and seeing your graph, it makes sense now. I was having similar issues with my 02. I don't tow anything, but I was noticing a loss of power under hard acceleration, and it was visible using my Edge CTS to monitor the IPR and ICP at the same time. The tunes I had were old, so I had them updated. (swamps) It runs much better now, but injectors are in the future for me. I'm looking at getting a set of 200/30% hybrids and a Garrett 38R. Probably won't happen until next year. Along with that will be a set of traction control bars thanks to someone I know writing about them last week and the better handling and feel they have in their truck!!

A good friend of mine who does a lot of work on my trucks told me that a new HPOO like a T-500 would help with the ICP, but if the problem is in the o-rings, you may as well put that money towards some hybrid injectors. The factory HPOP is more than enough to run them.

 

I asked the diesel injection people as to what healthy stock injector pulsewidth is and the said factory numbers are between 1-6. I see about 2.83 at idle. I see up to 5.5 when I'm heavy into the throttle.

I plan to pull My valve covers today. On a side note I picked up a used tookbox/60 gallon tank. So I have two projects now.

 

The book says 1 to 6. What the book doesn't specify is under what circumstance the PW gets as high as 6: Starting. The oil pressure is at its lowest at that time, so the PW has to go wide to compensate. 5.5 ms on a running truck under a load ain't gunna be cool.

 

So what do most of your trucks pulse width idle at? Mine idles at 2.8's.

Also I got the valve covers off and see no discernible problem with anything. I took a short 1 minute video of each side.