fuel economy problems

Check your fuel filter, see if there is any bubbles in the fuel and the level. Sounds like you may be sucking air some where. With the winter additives you will see a drop in fuel economy. Is your oil temp getting up to operating temp, 190-200? If not then your running cool, Diesels need to operate around 195. You may have water in the system as well. Put some additve in it like howe's or lucas. Your fage on your information. These are some of the things I can think of, air filters good?

 

After you check those things then there are several other things to check out. 5 mpg isnt typical for that detroit. I am just finishing up some repairs for a detroit getting 5 mpg (mine) and have replaced fuel pump, fuel line check valve and now doing all 6 injectors after having an overhead done. My fuel lines are fine (look for wet spots on them) and CAC is ok.

 

plugged air filters. and a slowly dieing turbo was my poor fuel issue.

 

Y'all never even asked him what motor year ect??

 

5.1 is what I get with mine. A Fleet air filter made no change, neither did an EGR Tuner. My gut says the exhaust is restricted so that's next. I do suspect that the only real solution is a full EGR delete.

Or just buy something with a pre-ACERT CAT.

 

OK.hope it will work.

 

Wow!!!!!I have a 60 seies det with egr system. Pulling 2 48' trailers loaded I get 5.3-5.7mpg. Single I'm over 6. In the warm months I can range from 6.8 to 7.8. Depends on the wind, how heavy and the terrian. Boardhauler I'll have to say something wrong.

 

It does great on the dyno & shows no codes.

I pull a curtain van on the west coast, 77-80K all the time, big hills & lots of roller coaster 2 lane road. I was still expecting 6 or close to it. For 5 years before I bought this truck I was driving 379's with C-15's in the same application and getting 5 with them. I'm not a happy camper.

 

We don't need no stinking details around here. We're truckdrivers!