New to the forum so take it easy. I'm looking for a list of items to inspect or service to return to 20 MPG.

I purchased a stock 2001 F250, 5 sp w/ 210K miles on the clock. Last August through October I was able to get 20 MPG driving mostly highway. The MPG was as low as 14 on winter blend fuel. Now that it is warmed up I have 225K miles on the clock and my MPG has returned to 17.3. Where did my 2.5 MPGs go. I liked getting 20 MPG.

Same oil brand, same tires, air filter and fuel filter replaced 10K ago. Recent repairs include EPBS tube clean-out and intercooler boots. When I get after it hard and stand on the brake, I can get about 17 psi boost at 3K rpm using a guage "T" into MAP hose. Truck runs great but seems a little underpowered at lower rpm (<2000).

 

Are you hand calculating mileage, or using the Lie O meter on the over head?

 

You gotta love the Lie O Meter! Today mine said 28 mpg YEA RIGHT!

 

All hand calculations.

 

Welcome to the forum. I would check the up pipes around the back of the turbo for leaks, if its still stock the gaskets could be leaking.

 

Welcome to FTE....Have you changed you fuel filter lately?You may need to do the in tank mods.May have some restricted socks in the tank.Sometimes if the EBP sensor is plugged it will not read and some have gotten better mpg's after cleaning that.

http://www.guzzle7pt3.com/ebps.php

http://www.guzzle7pt3.com/hutch.php

 

Not sure where you are located but could you still be getting winter blend fuel? Or some amount of it still in the stations tanks? Your mileage may still come up some more if that is the case. Maybe double check all the boots again for leaks. Make sure you are checking the two boots on the intake plenums also.

 

Im having the same problem. Looking forward to what you find out.

 

subscribing

 

I checked the up pipes this evening and they are soot free. When I did the EBP sensor tube cleanout I verified the gate at the turbo was free.

It could be the fuel tank unit. I'll take a look at that in a couple of weeks after I run the tank lower on fuel. If I have a fuel tank pick up problem wouldn't a diesel truck loose power on a long hard pull like a gas unit?

 

Just looking at my dash fuel gauge it is obvious the mpg is unaffected by the return to regular (non-winter blend) diesel. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
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I haven't ran the tank empty enough yet to make the tank mods. Maybe next weekend. <o></o>
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I was able to verify the exhaust pressure at the EBP sensor. It should be 34 psi max and the most I could get was about 23 pis at 3000 rpm loaded. The epv rotates freely and is rotated fully ccw with engine off (arm retracted).<o></o>
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I verified the ICP operation with an Ohm meter. The ICP output voltage was .8 Vdc idle (should be .88-1.19) and 3.4 Vdc WOT loaded. I assume the low reading at idle is volt meter error but is worth watchng closely.
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I previously measured about 17 psi boost at the map sensor. <o></o>
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The fuel supply pressure at the filter bowl pre-filter port is 60 psi. I replaced the fuel filter last month. <o></o>
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Next I'll be focusing on temp sensor and fuel rail pressures. <o></o>
Do you have any other areas that may cause reduced mpg and not set the engine light.<o></o>

 

The fuel pressure left head fuel rail measured 60 psi at idle. I'm not going to bother checking the right head cause the truck runs so good. The tank is pretty empty so this may be the weekend to check out the fuel tank.