Millage loss with stock injector replacement

[alewis]

Hi guy's, anyone experience this one. I have a 06 5. 9 with 96k on it. Driving normally (for me) the overhead always would show 19-23. I started to get a shutter sometimes at idle at stop lights, took it to the dealer , was told it needed injectors, had injectors replaced, shutter problem seems to be gone but so is my millage now I'm at 13-17. The mechanic , a well respected factory trained one that has allot of experience with these trucks , told me this is normal and that i need to hook on to something heavy and give it a workout and the millage should improve. I dont really ever pull heavy but I'll try it if this sounds logical to you more experienced guy's. Thanks for the help.

 

[HBarlow]

No, that is not logical or truthful. I can't diagnose your problem, but pulling a heavy load is not going to influence the injectors.

 

[Rascal]

The overhead readout isn't very accrete. Would like to know what the milage was before and after the new injectors with a manually calculated mileage.

 

[MChrist]

Alewis, first, welcome to the forum. Second, the overhead mpg readout is commonly referred to as the OLM (Overhead Lie-O-Meter).
Hand calculating is the only way to tell how your mileage is doing. Mine will say 28-30 on a trip, when it is actually 21. 22 on the OLM is closer to 15.
Now, I'm not a mechanic. . so I can't swear that pulling a load will "break-in" the new injectors... but that's a new one to me. I don't really see how.

 

[cerberusiam]

... and... . If the dealer installed reman injectors it could actually have pooched the mpg. Only way to verify is do a hand calculated run to get actually numbers.

 

[CSkal]

I agree with all of the statements above. My OH used to show mileage at 27-29 MPG with stock injectors. Once I replaced my injectors with DDP 50's, my OH started showing 21-23 without changing driving habits. My mileage has not dropped when I compare hand calcs of before and after injector replacment.

 

[MChrist]

CSkal, how do you like your DDP 50s?

 

[SWithrow]

Called my local Dodge dealer and was quoted $600 to R&R one injector with a reman. They did not have a price for new injectors.

I performed this task over a year ago (Fairly easy task) with 6 new injectors and cost was half what the dealer quoted.

 

[HBarlow]

IIRC, the overhead fuel mileage guesser doesn't actually calculate fuel mileage or even fuel flow rate but a combination of throttle pedal opening and miles traveled.

Perhaps the old set of injectors was leaking so required less throttle pedal opening. Your new or rebuilt injectors don't leak so require greater throttle pedal opening to provided the same acceleration and road speed.

Only hand calculation before and after can actually determine your actual fuel mileage and would require several tanks full to get an accurate number.

 

[RKerner]

I agree with all of the statements above. My OH used to show mileage at 27-29 MPG with stock injectors. Once I replaced my injectors with DDP 50's, my OH started showing 21-23 without changing driving habits. My mileage has not dropped when I compare hand calcs of before and after injector replacment.

CSkal, how do you like your DDP 50s?

Stainless bodies or standard? When I called DDP they recommended SS but a guy has a hard time ponying up for them. Sorry for the hijack.



When I pull heavy, my empty mileage goes up a little for a while until I short trip enough to put a fresh layer of carbon on the pistons and combustion chambers.

 

[alewis]

Thanks for the info guy's, I have not hand calculated but just a comparison from before and after. I will do the math when I get home from my deployment.

Thanks again.

 

[TCDiesel]

SS (Stainless Steel) CR Injectors DO NOT exist. Any company referring to the NEW version and Selling on the platform of stainless steel is not in tune with CR Bosch injectors or its a another sellers pitch.

 

[TCDiesel]

Shiny material is not a good indicator of raw materials.

 

[CSkal]

I like my DDP 50's, I just have a little bit of rattle (timing?) below 1800 RPM without boost. I am thinking of getting a Rokktech sensor as I have heard that adjusting the timing a little bit can help with the rattle. Injectors were pricey as a six pack, but still cheaper than the remans that Dodge was quoting. Oh, and they were NEW injectors with the 50 HP tips. I have not heard good things about the remans from Dodge.

 

[JMarketos]

To OP- hope I'm not adding more mud to the water, but...
[1] Agree with others, do the hand calcs to check.
[2] Is there any chance while the truck was in for injector work, maybe the dealer did a "free update" and re-flashed the ECU, and now you're running a different fuel map than before?

 

[Scooby]

You do hear that some heavy towing will help break-in "the engine"... but by 98K miles - that should be taken care of by now.



I know that after I tow my fiver, my truck feels like a sports car! The engine also seems to be quieter. But I imagine that's more related to the fact that I just jettisoned a 13,000 lb. anchor!

 

[alewis]

As far as I know no reflashes were done , just dodge rebuilt injectors were installed and valves adjusted .

 

[steved]

Typically when they do a flash, they include a sticker under the hood indicating so.

 

[CSkal]

Typically when they do a flash, they include a sticker under the hood indicating so.

That's how it is suposed to happen, but the reality is that it does not always occur. Maybe only flashes that affect federal emissions require a stocker?

The flash is a good point; I hadn't thought of that.

 

[steved]

That's how it is suposed to happen, but the reality is that it does not always occur.

The reason I qualified that statement with "typically".