Loss of boost ( and power )

[WestTN]

I just washed my truck and took it out to get all the water out of the calipers and discovered I have lost some boost pressure since earlier in the day. My boost gauge shows a peak pressure of just under 20 psi that quickly fades to about 17. 5 psi. Earlier it was slightly over 20 psi peak fading to about 19 or 19. 5 psi. This is not at high rpms where de-fueling would be the cause. The air filter is fine. No changes have been made to the engine at any time. I am halfway through a tank of fuel, so I doubt it is plugging the fuel filter. Total mileage is 9799. Fuel mileage has never been great.

 

[KatDiesel]

Checked all your hoses and clamps on the intercooler and intake system? Boost leak sounds possible to me. Have you ever checked your fuel pressure out of curiosity? Some people say when thye change lift pumps and get their fuel supply back, they gain boost as well due to the healthy supply of fuel.

 

[brucew]

loss power and boost

if your loss is accompanied with a hissing sound might be a loose clamp associated with the turbo. i lost power while towing only to find out 2 of the 3 aircraft type clamps were loose. i received the help from someone at this web site and sure enough they were correct.

 

[WestTN]

Thanks to all for your input. Unfortunately the mystery continues. I've checked the clamps and all were tight. I tried the truck again under the same conditions and the boost is back. I'm starting to wonder about fuel pressure.

 

[pwr2tow]

When you washed your truck did you wash the engine compartment and did you use high pressure water.



Ron

 

[WestTN]

pressure wash

Emphatically NO! I washed a computerized car engine once with a pressure washer. It took about six months to undo all the problems caused by that 5 minute wash. If you ever plan on pressure washing, I recommend you start with the service manual to help locate all the connectors, remove them and apply dielectric grease to all contacts before using the pressure washer.