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i am have power problems, i can't pull any hill. do you have any suggestions on how i can get more power
Optional Information: Make: peterbilt Model: 379 Year: 2001 Engine: cat Already Tried: new turbo, boost sensor, tune up,
Hi. Thanks for using JA! I will try and help you out.
There are several things that can cause low power. The first two that come to mind is low fuel pressure and low boost caused by a leak in the air to air cooler.
Your engine should maintain a pressure between 75 and 90 psi at all times. If it drops below 75, the engine will have low power. There is a plug on the fuel filter housing you can use to check pressure. If it is low, I would suspect a failed fuel pressure regulator. I see this a lot. The regulator is located underneath the filter housing. IT is about a 1 inch looking plug. If the regulator is OK. I would next suspect a weak transfer pump.
If the fuel pressure is OK. I would next suspect there is a leak in the air cooler of the engine. I see this a lot as well. To verify, you will need to pressure test it. You can cap off one side and put 30 psi on the cooler and then spray with soapy water. If there is a leak, you will see it.
Please reply back if you need more help.
i read that a lot of people are having power problem and they are flashing there ecm and changing there turbo, have u heard anything like that
Yes. I have seen folks uprate the software in the ECM and if needed, change the Turbo.
However, I would have the fuel pressure and air cooler checked first. If there is a problem with one of these, uprating the Horsepower will not help. If the Fuel pressure and the air cooler are OK, uprating the software in the ECM will help.
Reply back if you need more help.
my engine serial number starts with 6nz but they say i have a MBN engine, is that possible
No that should not be possible.
There should be a sticker on the valve cover of the engine that shows the serial number. If the sticker is missing, there should be a metal tag on the block underneath the turbo.
Both the 6NZ and the MBN were released at the same time in 2001. Then in 2002, they stopped making the 6NZ and the MBN was in full production.
Maybe when they run the vin number of the truck, the Peterbilt system is telling them it's a 6NZ. If that is the case, there system is most likely wrong.
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