I'm taking the truck into a feller Thursday. He used to be the Diesel Mechanic at a local Dodge dealership till he got tired of their crap and opened has own shop. He worked on my truck when it was still under warranty and really seemed to know his stuff. He always went the extra mile to make sure everything was taken care of and always managed to "overlook" any performance mods that may have shown up.

Upon talking to him, he is thinking it may be some type of solenoid inside the CP3 that controls rail pressure. He's had to change out half a dozen over the years, and while the symptoms aren't a prefect match, he feels it's a good place to start.

He's said he's gonna take electronic readings on the injectors, pump and all the different sensors to try to narrow it down and then call to let me know what he finds and go from there.

I Told him if he finds ANY discrepancies with the injectors, I'm just gonna change 'em all out. He said if it comes to that, he'll change 'em out for $100.00 labor. That didn't sound too bad.

 

I would have to say it hangs because rail pressure hits a spike at those rpms my truck does the same thing

 

I got a call from my mechanic this afternoon with a progress report. While he hasn't 100% completed the diagnosis procedure, He informed me things are pointing toward a bad injector. He was pouring over some Cummins engineering bulletins he has access to (ex-Cummins tech) and found one that matches my truck's symptoms to a "T". Something about one or more injectors leaking too much fuel into the low-pressure return, which throws off the rail pressure sensor (or something like that). The bulletin gave him a list of things to check/eliminate before concluding on a bad injector(s), but he's running out of things to check! He'll know for sure tomorrow.

---AutoMerged DoublePost---

Well, my mechanic just called. The truck failed the leaky-*** injector test. He said the final test prescribed by the Cummins engineering bulletin instructed bringing the engine up to operating temp and measure the outflow from the injectors into the low-pressure return line. Said outflow should not exceed 100 ml per minute for all injectors combined at idle (if I remember him correctly). Well, it was flowing 120mls and that number was rising as the engine got warmer (engine temp dropped as he fought to get the return line off). 160mls is considered a major problem. It is unclear if it is just one injector acting up majorly or if it's 2,3,4 or all 6 leaking just a little bit, but it doesn't matter. I had told him from the beginning that if ANY showed signs of trouble, I was gonna change all 6. Now all I have to do is go out to the money tree in the back yard and ask it to **** out about $4000.00.

 

$4k?!!!

That's crazy. What are they gold plated? Why not send them to Don at F1 and get one of the milder Flux builds for like $1,100?

 

I wish. Problem is you need good bodies for Don, or anybody else, to put their nozzles on. If the bodies are shot (like in my case), then nozzles aren't the answer. Actually, I'll need about $3600.00, give or take. Then I'll get around $1200.00 or so of that back for the cores, depending on who I go with. Then the couple hundred Bill charges for the labor.

 

Call Isaac at USA freedom diesel in MT 866-225-9153 or 406-880-4076 tell him Andy sent you! You won't be sorry!

 

I didn't realize the return flow condition indicated a bad body.

 

Yeah. The way it was described to me by someone on a different forum, the return flow issue is attributed to a "loss of tolerance" inside the injector body (though I may look into that more). I'm not sure what actually causes it though. Not sure anybody really does. All I know is, I've always been really **** about changing the fuel filter, before the AirDog, every other oil change (12,000 miles) and I've used PowerService additive every time I added fuel to the tank to help with lubricity since the EPA decided to push this ULSD fuel down our throats. Maybe that's the reason I got 102,000 miles out of them instead of some people's 60,000?

I've only had the AirDog on about 2000 miles now and haven't changed that filter yet. I always used Fleetguard filters in the stock filter can, though I imagine they were the stock 10-micron units, rather than the 2-micron ones that now seem to be "required" with these common rail injectors to survive.

 

Yup think of it as wear from things smaller than 10m "stock filter" put in a 2micron asap if you want to save your injectors! Once the return goes over 120ml your done! And the parts for rebuilding have not been released by bosch yet! So your stuck buying new ones
or remanned from bosch!

 

I've got a 2-micron filter in the AirDog right now, with a new spare one in the box under the seat. It's all that will ever be used if/when I get the new injectors. (the money tree out back isn't co-operating as of yet)