Check your intercooler boots. I had been trying to find my mileage problem for MONTHS! Had no fuel leaks, no signs of anything wrong just HORRIBLE mileage.

Got on a dyno last Saturday with Mid-TN TDR chapter, well this dyno lifts the truck up in the air.... 2nd run someone was hollering BOOST LEAK!

Got out the flashlights and started looking.......passenger side boot at the 'cooler was in horrible shape, and the rest of my boots were a little loose. Tightened them all up, and replaced the one boot and noticed a DEFINATELY throttle response change as well as mileage! No #'s to report yet because I still haven't went through a full tank with it fixed but I found my problem!

Oh yeah....I could still hit 45psi if I floored it.....so no signs of a boost leak anywhere until the truck was in the air!

 

Mine definitely has some problems. I am getting about 12-14 city, not much better highway. I'm guessing it has something to do with a poor plate setting (crooked?) and the fact that my afc is slid all the way forward (for more pre-boost fueling.) Since I rarely get on the go pedal, I rarely get much boost. My conclusion is that I am burning my fuel too inefficiently. Does this sound right? As an average, I cruise around town between 35 and 45 mph with a pre-turbo egt reading of about 450-550.

Can someone smarter than me help???!

 

Whiff, have you checked the clamps on your boost boots? When we bought our '97 they were very loose.

 

Por mileage

Check first for a plugged catalytic converter , fuel filter, or air filter

Check for loose or cracked boost line to the AFC housing on the Injector pump

If diesel produces clouds of white smoke when first started, check fuel injection timing

Defective Injector Pump Fuel Overflow Valve

Defective fuel shutdown solenoid can restrict fuel supply.


Check fuel pressure

Check for a turbo/wastegate problem -

Fuel pre filter screen clogged - screen should be checked every 24,000 miles.

 

how should I look for boost leaks in the hoses? easiest method ?

 

Look to see if there are any places that are rubbed through, cut or torn. And tighten the clamps (8 of them) with a 7/16 or 11mm deep socket and end wrench.

 

Thanks for the help. I'll check the boots. Cat isn't the problem. I hate cats. Had to part company with her. I'm thinking maybe it's in the boost line. I don't have a fuel pressure gauge. Maybe it's time I got one.
Thanks for the help all!