Injector Return test and PRV

[Lebo]

Hi,

Im still working on this P1223 excessive return code after replacing all 6 injectors (BBI stage one new not remans) and connector tubes. My question is, on the injector return test is there a way to isolate just the return going through the PRV? In other words a way to just check the PRV return, not the CP3, and not the injectors? I would greatly appreciate any help.

The last mechanic said he checked everything again, connector tubes, CP3, PRV, FCA, Injector return flow etcetera, and said it all checked good. The new mechanic said the PRV is leaking, even at idle, and that is the problem. However that PRV is only 3 months old and the last mechanic put in a PRV plug to make sure that wasn't the problem. I am getting this P1223 code 8 times in 60 miles while towing and no one can track it down. More to the story but I'll start with the PRV question. Really appreciate the help.

Thanks
Lebo

 

[Ozymandias]

Was this TSB done to your Truck?

https://www.turbodieselregister.com/threads/tsb-18-006-12-and-dtc-p1222-p1223-questions.241426/

Other ways that's might the point to start from.

 

[Lebo]

I’ll check on that Ozy. I’m not the first owner. I’m traveling right now but will get back to you. Thanks

 

[Lebo]

I don't have an answer yet on that TSB but I should know sometime later today. Are you able to isolate the Pressure Relief Valve during the return test or does that return fuel get mixed with the injector return? I'm working on learning this stuff so if it sounds like a stupid question bear with me. I am having a hard time finding any detailed schematics on the common rail fuel system. The reason I ask is after being at the dealership for 2 weeks their answer is my PRV is leaking at a CRAZY price. A PRV I replaced in 15 minutes 3 months ago for $60 when I first started trouble shooting a drop in rail pressure issue. I am thinking they are looking to replace the entire rail. Any way I just want to know how they determined if it was the PRV leaking. Of course, I'll ask but would like a better understanding before I do. They told me they did a injector return test to figure it out. I would like to know if that test isolates the PRV return fuel.

Thanks
Lebo

 

[MGreer]

Lebo,

The Miller 9013 test fitting screws in place of the banjo bolt on the prv, it isolates the prv from the rest of the system. If the shop performed the test thoroughly they should have used this fitting during the procedure. Do a search for "hpcr cummins", it will show a you tube link that has four videos from dca. The fourth video performs the fuel system tests. This is a good set of videos that will help you understand the hpcr system and its tests.
Hope this helps

 

[Lebo]

MGreer,
Thanks a lot man. I really appreciate it. The issues I have had with this truck have been a beat down. Seems to be a combination of things that I think I am finally sorting out with the help of forums like this. I am afraid there is more to the story than just the 1223 code but I'm getting close. I'll do a write up when I get this all squared away because I have learned some nuances that have really given me a headache. The are a lot of "I have a problem" posts but not everyone comes back to post the solution to the problem. I'll be sure to let everyone know what I come up with. Thanks again.

O yeah, I can't find the write up on the TSB 18-006-12. I scrolled through the link that is listed on the TDR home page. Selected the year group but can't find this TSB. Anyone have a direct link? No joy on my Google searches. Just want to read the TSB. Thanks

 

[Ozymandias]

Hi
If you find the time you can Google and find the factory service manual for your truck on the internet as a PDF with something like 1400 Pages.
In there is all the information you are looking for.
Need some time to find but it is there, for free.
Ozy

 

[Lebo]

Thanks Ozymandias.

 

[Lebo]

Just a little follow up for anyone who cares. I went to the dealer today to talk to the mechanic who worked on my truck. He said my injector return flow checked good but that I had some fuel dripping out of the PRV return line during the test. So one mechanic says that the PRV is the problem and the other said it checked out good. I think I am going to put a race plug in place of the PRV to see if I still have a drop in rail pressure as a tie breaker. If that doesn't pinpoint the problem I guess I'll take it to another shop. Called a guy today and he keeps a trailer at his shop with a car on it so he can duplicate an under tow condition. That is when I get the 1223 code most often. He told me he gets at least 2 calls a week from people that are having similar problems after putting in new injectors. He prefers to bench test the injectors vs the return flow test. I really hope it doesn't turn out to be the injectors. This time around I went all in on new ones so I don't think it will end up being them but this code really started popping up right after I had them installed. If it does I'm going to drive it off a cliff. This is really getting old and expensive but I am all in now. I want to find the problem. I think it will turn out to be one of the things we have already checked but maybe misdiagnosed. Only so many things it can be. CP3, Cascade overflow, FCA, PRV, connector tubes, excess injector return, what else?

As far as the TSB 18-006-12. I can't find it online and really have no idea if it was ever installed. However, the truck was flashed with the latest Dodge flash as a last resort and I assume that had to have the 18-006-12. Throttle response, which I have been chasing for years, seems much better after the flash. I asked the mechanic to make sure it was flashed back to stock because it was better then the EFI Live tune. The EFI Live is a whole different story. I think a SMARTY tune was on the truck and the installer didn't flash back to stock before loading it on my truck. I never felt like EFI Live ever took. I could be wrong. I just know the tune wasn't much of an improvement at any setting. As a side note, I was getting the P1223 code before the recent flash. Flash and injectors were both done within about a week of each other which doesn't really help me see if one has to do with the other. I decided to try a stock flash because nothing seemed to fix the sluggish throttle response down low. This re-flash seem to solve that but I can't say with 100% certainty.

 

[sag2]

Search "Injector return flow test". The last post on the second page shows two photos how to test head return using the 9012. The 9013 is requirec to isolate the PRV from the pump and head return.
Sorry I'm at SEMA this week and can't reload all the photos.

 

[Lebo]

Thats Sag2. I think I might have seen that post. I'll look again. Have fun at SEMA.

 

[Lebo]

Another update if anyone cares. So I got my truck back from the dealer and they said my injector return was a total of 30ml for all six injectors. The mechanic said he did the test at idle and ramped up to I think about 20Kpsi. 30ml seems very tight. The previous shop had it in the 140-160 range for brand new injectors. Someone or both are wrong. Also, the dealer said I had a leaking PRV and wanted a crazy amount to change it. I said na, I'll do it myself. I went to check/change it the other day and found out that the last shop left a plug in it. So my question is, how can the dealer say my PRV is leaking if it had a plug in it. The threads are good to go.

 

[Ozymandias]

That's hilarious and thanks for telling us, even if I can not help here I'm always interested in stuff like that to learn from.

 

[PawsWet]

Lebo,

The Miller 9013 test fitting screws in place of the banjo bolt on the prv, it isolates the prv from the rest of the system. If the shop performed the test thoroughly they should have used this fitting during the procedure. Do a search for "hpcr cummins", it will show a you tube link that has four videos from dca. The fourth video performs the fuel system tests. This is a good set of videos that will help you understand the hpcr system and its tests.
Hope this helps

I’d like to review these videos, but couldn’t find them.
Who is dca?
Did not see these videos appear with the search string provided.

 

[MGreer]

Try this link:
DCA was Daimler Chrysler before they changed it to FCA

 

[Lebo]

All right all right. Recap: Losing rail pressure and getting P1223 and P0148 code. I said back in November I would provide a solution to this problem if I ever figured it out so the next guy may not have to go through all the money and difficulties I have gone through. I am not quite there yet but I have the first bit of good news I'v had in a very long time on this truck. I had an HVAC guy out to my house to check on the heat pump and we started talking about our trucks. He recommended a diesel repair place that is, ironically, just about 10 minutes from my house. I took my truck there and after the new mechanic and I talked he said the best thing to do is start over from square one and I agreed. I figured this problem is something very unique or the last few shops misdiagnosed one of the steps in their troubleshooting. The new mechanic performed the following.

1) He did an injector return flow test, came out over specs at 180mil. Apx 500 miles on brand new injectors. .
2) Checked connector tube torque, and found them 1/3 to 1/4 turn loose.
3) Re-did the test and they were under specs at 150mil.
4) Checked the return on my FASS..checked good
5) Did a injector pump return/CP3 return test and it checked good

The previous shop did all the steps above except the lift pump test. They installed the FASS and it is fairly new so I assume they assumed it was good. They also put on a different CP3 pump to rule that out. Said everything checked good.

After performing the above steps the new mechanic said given the history the next thing to do would be to swap out the CP3 and see what it does. Again, I had all this performed at a previous shop and it all came back good to go. When the new mechanic put on one of his CP3 pumps the rail pressure went to 23K. Previously all it was getting to was 19-20Kpsi. So right now it looks like the CP3 was the problem all along and the previous shop(s) misdiagnosed the CP3. I know you have to send off the CP3 to get a valid test on that particular pump but swapping it out with a good pump is a good way to rule it out. The previous shop said they could only get the rail pressure to 20Kpis even with a stroker pump on. I will post back if the CP3 turns out to really be the problem. Only 130k miles on the truck. He told me he wants to drive it a few days and check the PRV with the new pump on. We will see how it goes but I am hoping this is the answer.

 

[Lebo]

I have had my truck back for about a week and have driven to and towed with it without getting the P1223 code. Mechanic (who was awesome) replaced the CP3 pump and so far no P1223 or P0148 code so it looks like that was the issue. Hope it helps someone in the future.

 

[petersonj]

@Lebo, I have been following this thread and I want to thank you for posting the final outcome. It sounds like you have resolved your problem, but I would like to hear how well your engine is performing two or three months from now just to confirm that all is well. Thanks.

- John

 

[Jdorfmeyer]

Great to hear you most likely found the issue!

 

[Lebo]

No problem PetersonJ. I can't tell you how many threads I read that sounded just like my problem but then I would get to page ,2, or 3, or 4 and no closure. No solution. Guy just disappeared and I'm like man I thought this was the one that was going to solve it for me. I'll post back in a few months with an update. Still seems to underperform when I am towing but I went back to a stock tune when we were troubleshooting. I am going to take it back to this last mechanic and get my EFI live back and running. He is a good dude and can't believe he's been right down the street for the 4 plus years I'v been messing with this truck. Crazy