Loosing Mileage
In Sept I drove my 6BT /Getrag/NV205 72 GMC 1-Ton 4x4 w 4:11's on 35"s from central California to South East Iowa.
On the road trip, I had a mechanical problem in Evenston WY that DieselCruiserHead helped me out on. It was a stuck thermostat that did not show up until 7,000 elevation.
I was doing mostly 58 - 62 mph. Those of you who have drivin I-80 know that from Cheyene WY it is pretty much all down hill to Iowa. Round trip I got 19.6 mpg.
I had no other issues with the rig. Ealry Nov I went out to start my truck and I had fuel coming out of the injector pump in places that it should have not been.
I pulled the pump and had it rebuilt at the local Diesel Injector/Pump rebuild shop. I reinstalled the pump and set the timing correctly. The pump was rebuilt to standard specs, no upgraded springs, plungers or anything. It is outlined in this thread.
I just drove my rig pulling my trailer with a Land Cruiser on it about 1,800 miles over last weekend. Visalia to Calico to Eureka and back to Exeter. I burned 3 quarts of oil during the entire road trip.
Dring the road trip, I averaged 7 mpg. Doesn't matter if I was pulling a trailer with a Land Cruiser on it or jsut pulling an empty trailer.
It puffs very very little white smoke at start up and during throttle up when it is still warming up. When pulling my trailer with a rig on it and the first ecceleration going up a hill I see a vapor cloud come out of the tailpipe but only if someone is behind me with their lights on. You cannot see the vapor cloud in the day time.
My first thought was a cracked head but I'm not loosing any anti freeze at all. There is no "pressure" coming out the oil fill hole like it has a scored piston/stuck ring. There is very little oil residue coming from the crank case vent pipe. After a hard pull through some mountain passes, I pulled in for a fuel stop. After sitting about 10 minutes there was a spot about the size of a nickle under the crank case vent hose. I double checked everything and found no leaks anywhere.
Any suggestions? Am I expecting too much from my rig?
Thanks