2013 Prostar Plus Question - Need your opinion

Thanks Heavyd! Is there any shop you recommend for international trucks with maxxforce in them?

 

Only International dealers knows them the best. That is who I recommend. I know not all dealers are the same and you guys don't like dealers in the first place, but in a case like this, you are stuck. The techs at Freightliner will have no clue what to do with a Maxxforce and probably simply refuse you anyway. Sorry, I cannot recommend a specific dealer.

 

Hey Heavyd so I just picked up the truck from international dealer after spending $1400 more for computer diagnostic only and they installed new fuel filter assembly with the new filters. I just test drove it and the problem still exists. That's why I was skeptic about their diagnostic, because they only spent 30 minutes on the truck without driving and no snap test to figure out the problem. The truck still cant pass 58-60mph after 10 minutes of initial start and go. Now they want to show it to the manager on Monday to see what they want to do. I would think that they do this every day and they would know their stuff. Grrr I'm so frustrated. It's been 10 days without a load. I'm starting to feel the affect.

 

Yes, I understand your frustration. They should be eating this first repair bill. Which filter housing did they replace? The fuel pressure regulator is part of the high pressure fuel pump and not serviceable. This is seems like a dealer that doesn't get into too much Maxxforce or tries to avoid them.

 

The way they diagnosed it, that didn't make any sense. I was expecting them to test drive. None of the codes are related to the issue or anything to do with fuel pressure regulator. It seems the issue is intermittent and they should have test drove it. The change the one with fuel seperator filter.

 

Hey Heavyd! So here is the new update. The service writer said that he will work something out about returning the money back for the wrong diagnosis and putting back the original fuel filter housing back on,but the manager said today that he doesn't know why would he say that because it needed that part and now he's saying that it needs the new fuel pump because of the these 2 codes SPN 3055 FMI 15 and 3055 FMI 0. He said without even testing it again he knoew for 99.99% that it needs the new fuel pump.

 

Question heavyd! If the fuel pump is bad would I get the first 5 to 10 mins of good power and then it starts to derate? I can go 70+ mph normally for the first 5-10 mins every time I shut the engine off.

 

Hey Heavyd! I really appreciate all your help. So here is the new update. The service writer said that he will work something out about returning the money back for the wrong diagnosis and putting back the original fuel filter housing back on,but the manager said today that he doesn't know why would he say that because it needed that part and now he's saying that it needs the new fuel pump because of the these 2 codes SPN 3055 FMI 15 and 3055 FMI 0. He said without even testing it again he knoew for 99.99% that it needs the new fuel pump.

 

I would ask them to check for aerated fuel first. This is installing a clear test line between the low pressure pump outlet and inlet to filter module, or from the primer pump outlet to the low pressure pump inlet, what ever is easier. This clear test line is something every dealer has. If the fuel is aerated, it could cause your issues. However, those codes do and can come up with a failing pump.
3055-0 is fuel rail pressure exceeded maximum and usually happens with air in the system as pressure has exceeded 34,000 psi.
3055-15 is fuel rail pressure below minimum with maximum commanded, or basically not high enough when commanded to be high. Weak or worn pump can no longer make good pressure under high loads and high demanded pressure.
3055-17 is another code that gets logged with failing pumps, it is fuel rail pressure above maximum with minimum commanded, or pressure is too high after being commanded to be low. This is usually logged with 3055-15 and is a dead give away the pump is bad. What happens is during maximum engine load the ECM has to command the pump to full pressure in order to maintain the pressure it wants. To do this, it commands the fuel pressure control valve for maximum pressure. This valve is duty cycle control by %. The more it is turned on, the lower the pressure and more it is turned off, the higher the pressure. With a worn out pump that valve is basically shut completely off to get the most pressure out of the pump. Since the pump is worn it can't deliver the pressure the ECM wants and therefore the 3055-15 code gets logged. For example, ECM wants 32,000 psi, but pump can only deliver 26,000 psi and logs the code. Then, as soon as you let off the throttle, the pressure demand goes down but since the ECM has fully off that control valve it takes a split second before it responds and starts to lower the pressure. So the ECM now wants only 7,000 psi but the pump is still putting out 26,000 psi. Since the pump now over shoots what is commanded, it logs the 3055-17 code. It could be over shooting with a pressure spike above 34,000 psi to be logging the 3055-0 code but you still should see the 3055-17 in there to confirm the pump is bad.

This is one of those problems that requires the pump and engine to be a full temp to reproduce. When cold it won't happen because the clearances inside the pump are tighter. This will come and go too as you drive it. Once you idle it and let it cool down a bit from cooler fuel running through it, those tolerances close up again to provide good pressure again until the next heat and high demand cycle.

 

you are the best heavyd! Could an air in the airline cause the loss of power after 5-10 of driving every ignition start. I did see soda like little bubbles in the little fuel cup by the manual fuel pump.