Have EGT & boost gauges. No Diag. Trouble Codes (DTC) come up. Pull 16k lbs 5th wheel trailer/toys w/ this dually. Used to go fast up hills (60), now going (25). No one can diagnose problem w/ absense of DTC readings. Have to really watch the gauges now to avoid EGT. New turbo is expensive, so hoping there's an easier solution or at least concrete diag. before spending a fortune changing out everything and still risking not solving the problem. Turbo bad? High Pres. Fuel Pump? Waste Gate? Anyone have this issue? Help!

 

How's your fuel pressure?

 

How do I test my high pressure fuel pump to see if it's going bad?

 

With a stock fuel system the easiest way is to just listen to it. When you turn the key, before you start it, you'll hear it running. Sounds like an angry beehive when it's not pumping right.

Any drastic changes in fuel economy, extra smoke, poor running, or any other symptoms?

 

Won't hear it before start, only after engine is turning. Fuel delivery has been less and less. Used to smoke and run well, now it doesn't.

 

Why won't you hear it before it starts? That is when it is most audible. You may need to have smebody else turn the key over while you stick your head under the drivers door...closer to the pump.

 

Also....your fuel pump is electric. Unless your 7.3 is older than a 97 model

 

7.3 is hydraulic rather than electric so I won't hear it(QOUTE) ITS ELECTRIC

 

Went to check under hood as suggested, hear slight hum in valley and after a few secs, slight growl behind left front headlight, that's it.

 

Not under the hood. Under the truck. You fuel pump is mounted on the inside of the frame rail underneath the drivers side door. However, if all you hear from it is a slight hum then it is highly probable that the pump is operating normally.

 

Anything else to check? How to test high pressure fuel pump?

 

when was the last time u changed the fuel filter,and is the lid on the filter housing tight!

 

1,000 miles ago, and yes, it's tight and not leaking.

 

well low boost could be a leak and high egt could be a clogged muffler are pre filter on exhuast if you have one? just wait mybe others well chime in!

 

Have been desperately checking for leaks. It's cleaner under the hood than in the cabin! heehee. Exhaust, everything seems to be leak free. Have had a few people look at it now and no one can seem to find anything that could be causing the problem. It's had constant maintenence, etc., so there's very little wear anywhere. I know the low pressure, electric fuel pump is fine, but how do I test the hydraulic activated high pressure fuel pump? Could that be it?