poor m1009 mileage

[bigflew]

MY mileage on my 86 m1009 went from 20 to 15 in the last month also seems harder starting and smokes more at start up. seems to run good otherwise. The glow plugs seem to be working(volt meter shows a drop in voltage when glow plug relay turns on) (also the belt squeels when glow plugs are working. its always done that and tightening belt or replacing did not help.)the air filter seems ok but will replace anyway. Im wondering if I have an injector leaking or a injection pump problem?
any help would be great.

 

[Westech]

the cucv injection pump is kinda a pile of crap. Most owners will have to replace the pump in the first couple years of being back in full time service. A good thing to do is rebuild the Fuel injectors at the same time. The kits for all 8 cost around 65 bucks. If you can change a spark plug you can rebuild the 6.2 injector. Its that ez.

 

[91W350]

Are they blending fuel there already? The winter blended fuel does not have as much energy as good old #2 diesel. It would be early for us, but your area might be subject to much colder temperatures, much earlier in the year than we are. I have been getting #2 at the local CO-OP as they do not blend their fuel until it is really cold out. One of our local truck stops sells #2 diesel much later than the other five truck stops do. Glen

 

[bigflew]

probably not the fuel blend its been doing this for a month or more also started good last winter the few times i started it.

 

[rhinob]

What kind of driving are you doing mostly? I'm getting 16 mpg with mine, but that's purely in-town driving.

 

[southdave]

Like westy said pump and timiing

 

[kipman]

Pump and timing, mine dropped off to 14, new pump and injectors, feels like a new truck, will spin the tires in gravel now,

 

[chief1983]

Is IP timing something I should mess with, without a dyno to test my results? I read about that in an old 4x4 magazine I had, that advancing the timing on a worn chain got them another 10% of their horsepower back. But I don't have a way to verify results other than to check the exhaust for excess smoke.

Also, what's currently a good way to get my IP handled? Find a new one somewhere, or find someone to rebuild mine? What's a good place to send mine if that's the way to go? I'd love to get back to the 20mpg I've heard these M1009s can achieve, and I'd really love to have it in good shape for the cold weather.

 

[ranchhopper]

Check the fuel and air filters either being restricted will really affect MPG and they will make the engine smoke more if they are getting clogged..

 

[bigflew]

Looks like im looking for an injection pump
thanks

 

[Wolf.Dose]

The injection pump is not a very reliable peace of technology, however the fuel consumption over 20 mpg might have other problems, too. If the cluches in the THM400 start to slip, the fuel comsumtion will jump from 20 to 15 mpg easily, which I experianced. Change your transmission oil. If slightly dark and /or smelling somewhat burned, rebuilt your transmission! Caution, the differnece between normally changed transmission oil and burned one is very small! Compare with your transfer oil. The transmission oil should have after some 40000 miles almost the same colour. If darker, a transmission problem. I know, what I'm talking about after 14 years with a M1009 and 372000 km.
Wolf

 

[southdave]

Good point wolf.....