Fuel return test

[promisedland]

I had some hard starts [twice in the last year] so i had my shop do a fuel return test... I dont have my notes here, but i will find them.
What is the accepted limit? I 'think' my Ram was a 20oz per min.[??]
I heard 6oz is max....



Thanks for making this forum great!

 

[promisedland]

It is 20oz per min.....
Bump!

 

[MGreer]

I'm assuming the test you had performed was the injector return test.*

 

[promisedland]

Yup, to see how much fuel is returned from the cross over tubes/injectors

 

[cerberusiam]

The correct test is 180 ml in 30 seconds with the engine up to temp, 1200 rpms, and 20k is rail pressure. That is for good injectors, 240 ml or more is hosed. You can live numbers between 180 and 240 if there are not starting issues

 

[promisedland]

So, if i did my math correctly... [30 second test] Milliliters to oz= 240ml = 8.1oz

I had 20 oz per minute

240ml x2= 480ml [1 min]= 16oz....

I will find out on monday about eng speed/rail/etc.......

 

[cerberusiam]

At an idle with idle rail pressure WAAAYYYY over the spec for return fuel.

 

[promisedland]

Grrrrrr!
This test shows fuel leakage from the cross-over tube to injector body? Aye?
[ I had the tubes re-torqued...]
Or does this test show more then this?

I DO have occational starting problems.

 

[cerberusiam]

The test is designed to show injector bypass volume, when that goes too high the injectors are worn out internally. You should have no leakage on the cross over tubes it will show up in that test if it exists. Hard to tell if it tube leakage or injector wear unless you replace something. High return flow will cause slow\no start conditions because it takes longer to build rail pressure with the leaks. Too much leakage and it doesn't build the required pressure to fire the injectors.

 

[TCDiesel]

This is the touch tone to use At idle 03-04 60ml per minute is perfection..04.5-07 5.9 at idle 68ml per minute... testing injectors at Higher pressures can be misleading in truck... You need to compare the incoming fuel vs the return of the CP3, your return rates on the injector can be low BC low volumes of combustion fuel available, Generally if the idle pressures are above 80-90ml per minute you will experience long cranks, over 100ml per minute will require either to start in most cases.

Factor in the Tubes leakage as cerb mention really distorts the reading. If the LV/PRV leak excessively that just adds to the higher pressure distortion rates. Use low pressure return rates...

 

[promisedland]

Looks like i'm way over....
If i would just replace the tubes; are they reusable? = [ if i then get new injectors.]

I have had a few hard/sputtering starts
Normally, my truck starts great, not long crank times

I have some white smoke at cold [winter] starts

I have plenty [in my opinion] of haze at light/med throttle

My mechanic says he hears a slight miss/unevenness at 1200~ rpms

Thanks for your input!

 

[TCDiesel]

Tubes can be reused in most cases, once they are removed you can inspect the tubes for anomalies and scaring if they check reuse them. The tubes will only cause low rail pressure issue.. they will not cause smoke or looping, surging or sputtering.

 

[cerberusiam]

New tubes can be reused as long as the pocket in the injectors is not deformed or notched that would ruin the tube end. They are really meant to be a one time use but can be used again if you TQ them a little more than spec when reused.

If you have white smoke on start and hazing the injectors are done, the tubes won't help that. Best to replace tubes and injectors at the same time.

 

[TCDiesel]

O forgot to mention We make our own tubes for 6.7/5.9... I got fed up with the occasional problems with Cummins 6.7 tubes in 5.9.

 

[promisedland]

Thanks TC!
I have been pondering injectors for a while,*
50hp is what i want... Bms 50 sac has been on my list,.. Is the sac clean running? i want 400rwhp smarty tuned power for DD and towing.*

 

[TCDiesel]

OE is still your best bet, BMS just had a price increase and another BIG one is coming. Bosch World Wide has decided that Franchise laws requires BMS to increase pricing. I like OE stuff better then BMS.

 

[cerberusiam]

The BMS50's are very clean stock tuning, better efficiency with some tuning. To run the 143 degree tips which are really the best you need a little tuning to make them shine. OE is fine but the VCO nozzles are noisier and not as strong. If BMS is going to jack their prices then grab a set of the 143 50's ASAP. With good filtration and fuel will likely be the last set of injectors you buy for that truck and they will support some power mods nicely.

 

[TCDiesel]

BMS is original intend was to promote BOSCH race products, to Off road Race ONLY sales, The network of dealer sales to general public, violates Franchise, Tariff and Judicial laws. If Bosch world wide did nothing they were facing legal action, Even Bosch North America is fed up with BMS, Now that Bosch has lost GMs new D-Max contact, they will have plenty of support to fix BMS.

Obviously, the laws/Rules concerning Bosch products world wide are complicated sophisticated and complex.

 

[p-Bar]

BMS is original intend was to promote BOSCH race products, to Off road Race ONLY sales, The network of dealer sales to general public, violates Franchise, Tariff and Judicial laws. If Bosch world wide did nothing they were facing legal action, Even Bosch North America is fed up with BMS, Now that Bosch has lost GMs new D-Max contact, they will have plenty of support to fix BMS.

Obviously, the laws/Rules concerning Bosch products world wide are complicated sophisticated and complex.

TC what is D-Max doing for their HPCR system?

 

[TCDiesel]

Its My understanding DENSO ,IMO its just a shot over the Bow.

The whole BOSCH distribution network is screwed up..Example: Owners buys 2016 Ram/GM/Ford pulls the Injectors out and has them sent to X company or buys x nozzle, Installs them truck runs like crap, he takes it to the dealer and dealer says Injectors bad >>> Now according to BOSCH Franchise rules the License seller has to remove all BOSCH marking (except part) and place there Name or Label. OK the Tech remove the injectors sends them to FCA ...FCA forwards to BOSCH for warranty BOSCH eats the expense on Product altered or denies Claim. The area REP stated to me that the After market world was costing BOSCH 20+ million yearly in warranty Claims in N/A.

BMS dealers have NO obligation to BOSCH N/A . The authorizes Seller BOSCH certified is required to followed the rules or standards by legal agreement , And Just BC the seller/Dealer Claim authorizes doesn't Mean they are authorizes for everything, Most authorizing is Drive thru service ,Not Seller or Distributor... Heck I have found these drive thru service centers buying BMS stuff claiming Authorized seller... Big lie.