dirty injectors

[ludwigs32]

I have been trying to diagnose a fuel consumption issue(its very low like 8-10 mpg). I have performed routine maintinence on the vehicle. New tires, I use lucas every other fillup and that seems to improve my mileage slightly, but not consistently. (14-16 mpg) I have to replace the rear u-joints, will do that this weekend. Could dirty injectors be the cause?


thanks for the help...

[AFBLUE]

Give us some info on the truck?

[AFBLUE]

Give us some info on the truck? Year? Mileage? Trans? Mods?

Did you just buy this truck, and you are getting sub par mileage, or has you been watching it decline, or was it instantly you lost MPG?

Checked the Fuel filter, Air Filter?

Where are you located?
If they switched to winter diesel you will see an instant 1-2mpg loss.

[ludwigs32]

This is a 2002 f-250 superduty w/ a 7.3 psd and a shortbed with a supercab that I purchased in May of '06 with 40,000 miles on it. It has 90,000 ish miles on it. Im not sure exactly what trans is in the vehicle but it came with a hypertec transmission tuner? That allows me to change the style of shift from soft to firm, or vice versa. I currently have it set to a firmer shift because that setting tends to make the truck shift earlier giving it a lower rpm sooner. I have a K&N intake and a 4"exhaust. The tires are 275/85/16 AT series tires that I put on March of '08. I replaced the rear u joints in April of '08 (and they're junk already and i need to change them. When I had the tires put on the they said I have wear on my upper and lower ball joints ( so they could not give me the free alignment that came with the tire purchase) I noticed no play but it does pull slightly to the left. I change the fluids and filters regularly. When I first purchsed the truck it got 19-20 mpg and it seems about a year ago my mileage started to fluctuate as low as 14-15 mpg. since then I have gotten as high as 22 mpg on one tank of fuel that was a highway trip to ceadar point this last summer. Currently, I get 9-10 with the occasional 15-16 may be 18. I do ALOT of city driving MT and loaded . I even tried blaming the man for watering down my fuel to no avail. So I MUST be missing some other clue or combination of clues. I also burned about 3 tanks of off road in it, then I read that was bad so I changed the fuel filter and started running sunoco diesel thru it.
Thanks for reading

[bockhold]

whats your diff?

[tims02ford]

You might need new ones i do and i'm getting the same in mpg

[Phiber Optik]

How can you tell?

Cylinder contribution test?

I'm in a similar boat, I get 300 miles per tank, (100L - 26.5 GAL) = 11MPG with diy intake, 4" exh, 33x12.5" and 3.73's with an auto driving light footed unloaded. I was thinking maybe it's the torque convertor...

[AFBLUE]

Originally Posted by tims02ford

You might need new ones i do and i'm getting the same in mpg

I am lost.....New what?

[dubl_t]

AF, i think the dude meant new injectors.
MPG is a funny character. It seems no 2 trucks will get the same, even when set up similar. and careful what you "read" about what others are getting, some lie even if they don't mean to. and don't believe the guy who tells you he's getting 20 some plus with an automatic (but i AM getting 18 ).
If you suspect "dirty injectors", try emptying the fuel bowl, filling with Stanadyne, and running that.

[bockhold]

what hasnt been asked was what was he getting b4 he saw the mpg drop.