Medium and Heavy Trucks
Have Truck Repair Questions? Ask an Expert
Thanks for asking your question and requesting me. I will try and help you out.
Does the yellow check engine light come on when this happens? Or no light just low power and hesitation.
Thanks for the information.
Since the check engine light does not come on, I would suspect 1 of 2 things are causing your problem.
The first is low fuel pressure. If there is a low fuel pressure problem, the check engine light will not come on and the engine will have low power. Your engine should maintain a fuel pressure between 65 and 85 psi. There is a plug beside of the secondary fuel filter that is used to check the pressure. If it is low, I would first try the fuel filters if you haven’t already. If it is still low, you may have a failed fuel pressure regulator, which is located on the back of the cylinder head. I have replaced a ton of these for low fuel pressure. It is kinda a known problem. You could also have a weak fuel transfer pump or restricted hand primer pump, if your engine has one.
Second would be worn injectors. This has been known to happen overtime. If the fuel pressure turns out to be OK. I would suspect the injectors. I have seen this a lot.
Please reply back if you need more help or have more questions. I am happy to assist.
The only other possibility would be a sensor reading wrong. Like a boost pressure sensor or intake air temp sensor. They have been known to read wrong and cause the engine to have low power. If the sensors are reading correctly. I must suspect low fuel pressure or the injectors.
Hey. I just wanted to see how things were going. Please let me know if you need more help. I am happy to assist. If my information was helpful, please leave a good or higher rating so that I receive credit. Thanks.
Ok sounds good. Thanks for the update.