I bought 6 new Bosch RV275 injectors one year ago (the price was right - $425 for the set) and finally installed them last Friday.  The original injectors operated for 303,000 miles and had never been removed.  They were still performing well – as in smooth idle, good power, and good fuel economy.  I didn’t want to push a good thing too far.  The job went smoothly with the help of this site.  All of the old injector tips were clean considering the miles and years on them. 

 

I did notice however, that there is a black coating of something  kind of oily / powdery (not sure what it is) in the intake area just below the grid heaters.   It is not present in the air horn and the hose from the intercooler – they are very clean.   I wonder if worn valve guides combined with lots of exhaust brake usage could be the cause.  Maybe someone who has had experience with this can shed some light.  The marks are from me using a scraper.

 

I am having a problem with a very small leak with #1 injector line at the injector.   When I removed the injector lines, I did it in groups of three, but I left all of the blue clamping points tight.  When I put everything back together, the connection at the #1 injector showed signs of leaking (wetness on the head around the fitting) on a 5 mile test run.

So, I loosened the #1 injector line at the injector and loosened the blue clamp nearest the injector and then tightened the injector line followed by tightening the blue clamp.  No evidence of a leak on a 5 mile test run.  However, after a 50 mile trip the head is slightly damp around the  injector connection.  I will try again, but this time I think I will loosen the clamps and the mounts and repeat the procedure to get the leak stopped.  If anyone has any tips, please speak up.

I like the performance of the RV275’s.  I immediately dialed the Smarty tune back a setting. 

OEM injectors:                  SW5 – Torque Management 5,  Timing 1, Duration 5

RV275 injectors :                SW3 – Torque Management 4, Timing 2, Duration 2. 

Smarty Settings:

Torque Management (1-6)  Each higher number incrementally reduces torque management at low engine rpm’s.  Example: TM-6 equal zero torque management and allows for high torque at low rpm’s.

Timing (1-4):  Each higher number incrementally advances ignition timing .  (#1 is stock, #2 is stock with after market injectors)            

Fuel Duration (1-5):  Each higher number incrementally increases fuel duration.  (#1 is stock)

The RV275 injectors definitely deliver more fuel.  So far, the tune I am using with these injectors is performing well, lots of torque on the low end easy to drive without smoke.   I am setting the tune as to how I drive with a manual 6 speed transmission and operating engine rpm’s between the 1500 to 2000 rpm range for almost all driving conditions.   

I will post more information as I get some miles on the new injectors and let you know which tune I end up with.

- John

I'm not sure what I was trying to say earlier ^^^^^^ I think I'm losing it or already lost it. Reread my post, now trying to make since of it. Actually having a debate with myself about few things at the moment 

Just adding to the info on the topic of leaky injectors after a change/replace. I had a retired diesel mechanic years ago show me a way of seating the crossover tube to the injector properly. When seating the injector into the head and then installing the crossover tube you should push with your thumb on the end of the tube and at the same time rotate the head of the injector (I use a screwdriver that fits the slot on the head of the injector) counterclockwise the clockwise slightly and you'll feel the tube setting into the head the furthest it can go. Then tighten the injector hold down. Then when you tighten the fuel line nut down it will also seat properly in the head. I've done this on about 20 different injector jobs and always the line nut torques down to 30ft/lbs smoothly and no leaks. Hope this helps someone. 

24 minutes ago, rotohead said:

Just adding to the info on the topic of leaky injectors after a change/replace. I had a retired diesel mechanic years ago show me a way of seating the crossover tube to the injector properly. When seating the injector into the head and then installing the crossover tube you should push with your thumb on the end of the tube and at the same time rotate the head of the injector (I use a screwdriver that fits the slot on the head of the injector) counterclockwise the clockwise slightly and you'll feel the tube setting into the head the furthest it can go. Then tighten the injector hold down. Then when you tighten the fuel line nut down it will also seat properly in the head. I've done this on about 20 different injector jobs and always the line nut torques down to 30ft/lbs smoothly and no leaks. Hope this helps someone. 

 

I was taught something similar that I put into my install video. I don't rotate the injectors but I install the lock bars and don't tighten then down, but in do tighten the crossovers first then the injectors. 

 

I also loosen my blue lock bars too before tightening down the crossover tubes.  

 

It's saved me a bunch of headaches too.

The FSM calls for tightening the injector holddown first to half its torque, then back off the bolts to relieve the tension.  Next, tighten the injector crossover tube nut to 11 in/lbs.  Go back to the injector and begin alternating between the injector holddown bolts and the crossover tube nut until final torque is achieved.

 

@rotohead and @pepsi71ocean, I think that the goal of all of these methods are making the best effort to center the injector crossover tube into the into the injector housing using minimal force for a reliable seal.  I have watched a few videos that don't even consider the importance of this step.

 

- John