ISX 435 CM870 horrible MPG

[Rawze]

Some info on the crooks that hang out in in effingham...
http://rawze.com/forums/showthread.php?t...9#pid13279

Just be warned.

===

Fuel mileage issues are not usually hard to solve on ISX engines. One of the more common ones, besides the obvious boost or CAC leaks for the CM870 is the EGR valve getting mechanically stuck open.

What is the boost peaking? -- Pyro?

When is the last time you used algicide to rid the engine and tanks of algea?

Overhead valve adjustment and overhead cam inspection?

Injector leak test? -- Followed by a cylinder cut-out test to ensure each cylinder can run the engine by itself (running whole engine on only one cylinder at a time).>?

Delta-P replacement?

Inspected the exhaust and muffler for exhaust restrictions?

Pressurized the whole engine for intake, EGR, and exhaust leaks?

Just some starting points. A fuel mileage that bad should be easy to find. it has to be something severe. i have even seen peterbilt and KW trucks that like to get a fuel line leak to the tank on the passenger side right above the exhaust and drip drip drip fuel and it evaporates as soon as it hits the exhaust. Driver complaining about 3 or 4 mpg max.