Fuel mileage

[7.3dofbft]

hey guys im a noob here, but I did read in a tech article about poor fuel millege on a 7.3 powerstroke and it was due to the copper o rings on the injectors. I think Marc was the poster of it. I have a 99 F250 PSD 7.3 have had it for a year, truck runs perfect never had a problem except 10-11mpg. I have added 4" full exhaust, Diablo Sport chip, then switched to SCT X cal 2, does not matter still same exact millege each time. Like I said starts up every day , no smoke coming out at startup or during regular excerating , of course when I gun it she puffs out like a normal diesel. So I am going to try what he had posted in the tech article about checking fuel pressure on rail at start up etc, he said he went from 11mpg to 19mpg after replacing the copper o rings. Anyone know if the process of replacing them is too much for a moderate mechnic ability? Thanks...

[mschn99]

i didnt post it, Mike OB did. The problem is a possibility, but if you are uncomforatable AT ALL pulling injectors on these rigs, it should not be attempted. The possibility of hydrolocking a motor and bending connecting rods is VERY high if anything isnt done correctly.....

[7.3dofbft]

ow ok, Mike did, sorry bout that Marc, I hope this is my problem, I guess I will take her to the dealer to see what they say, I have no problems at all with the truck except 10-11mpg thats just horrible.

[LPstroker]

What was the link to this article? I would like to read it. Do you know off hand?

[7.3dofbft]

yeh the tech article is right here on this forum ,

http://www.powerstrokeforum.com/foru...ead.php?t=1542

[Banshee34]

Originally Posted by *******

Actually, I didn't think of that. I am going out of town this weekend again and it will be to a place where I know exactly how far I am going (235 miles). So I guess I'll just top it off when I get there and see how many gallons it takes. I was going off the odometer on my last trip. Could have been off.

So how did your mileage turn out???

[LPstroker]

Thanks Buddy

[tiny]

Originally Posted by 7.3dofbft

yeh the tech article is right here on this forum ,

http://www.powerstrokeforum.com/foru...ead.php?t=1542

Does anyone know where the easist place is to hook a fuel pressure gauge to do this test?

[jtomasik]

I have a Banks power kit (it's the one that adds about 140hp to the motor), and I get just under 17 with mixed highway/city driving, sometimes on the throttle, and sometimes nursing it. I was down on tire air pressure about 10psi at the time. I've since watched my tire air pressure more closely, but I haven't re-checked my mileage. Probably time to do that.

[splitpile]

So at what rpm does the fuel mileage really get affected?
200, 2100, 2200 more or less rpm's, NOOB just wanting to know