Medium and Heavy Trucks
Have Truck Repair Questions? Ask an Expert
Hi, my name is ***** ***** I will be glad to try and support you today. First I would like to welcome you to Just Answer. Could you tell me a little bit more about the unit you are working on? What is the make and year of the bus and engine that you are working on.
One quick thing to check would be the ECM fuses, if one or both of them are popped then the unit will crank all day and not fire. Any other fault codes or symptoms that you have noticed?
No unfortunately there isn't a manual way to check the fault codes. Is there a red or amber engine light staying lit on the dash all the time?
Please check at the batteries if there are two blade fuses? If they are not located there you can check around the starter area. These two fuses feed the ECM power and if one or both have popped it can cause the symptoms you are experiencing.
Check all fluids carefully, sometimes if the ECM is programmed a certain way it can cause the engine to not start if the coolant is too low, or it doesn't sense oil pressure.
Let me know what you find out of those two checks first. The HP pump is a possibility but could hopefully be something much more minor than that.
Thank you Sir, I know you had mentioned fuel pump suspected. There should be a connector on the top of the fuel filter housing to test fuel pressure. Are you able to hook a gauge to that housing to check what fuel pressure you are getting? Second would be to remove your fuel return line and put it into a bucket, when cranking see how much is coming out.
I am unsure of what your abilities or tools are so please let me know if you are able or unable to do those checks. We can attack at a different angle.
No problem Sir, Please keep me posted! Thank you!