HMMWV DB2 Injector pump fuel rate turn up observations

[dilvoy]

I recently installed a HMMWV DB2 Injector pump into a M1009 CUCV Blazer. These vehicles have the same 6.2 engine as the HMMWV, so I thought I'd do some experimenting. I installed a New DB2 that I removed from a new engine. I switched over the top cover to one that had the 12v fuel shut off and cold start advance solenoids. While I was at it, I turned up the fuel rate by 1/6 of a turn. Lets say that I took the fuel rate screw from 12:00 to 2:00. I made no other changes to the vehicle except for changing the fuel hose from the fuel filter to the injector pump. It's been driven for four weeks now and what a difference it has made. My Nephew and Father told me that it drives like a different vehicle. I noticed immediatly that it had more torque and the highway driving was superior as well as hill climbing. Even loaded, it can accelerate up a steep hill while driving on the highway, where before it might only keep speed with any added throttle application. Much less throttle is needed to cruise at highway speeds, so possibly there is no mileage penalty, but I have not checked fuel consumption. Infact I don't care as the drivibality is so much better. I have not noticed any other problems like overheating except that a U joint started vibrating a couple of days ago. The vehicle had the original U joints that don't have grease zerks and the vehicle has 69,000 miles, so I think the added torque hastened the inevitable. When I changed the joints, the one that failed had no grease and the other had just a bit in the caps. I did notice that there is some black smoke visible when hard on the throttle. I guess it's over fueling, so maybe a little less of an adjustment of the fuel rate screw would give the same performance without the black smoke. It's just a slight bit of smoke and just shows up for an instant, so I'm not going to do anything about it.
If I had known about the increase in power with this adjustment before, I might have kept driving my humvee while I amassed the parts for my conversion. Unfortunatly I diden't and was worried about not being able to catch someone in a Geo Metro or some other low power vehicle that might have hit and run me, so I parked the slug.

[Kurt Lesser]

George,

Is this the little allen head screw that you can see through the bottom of the solenoid cavity in the injector pump? Did you have to rotate the engine by hand to move it into a position where it could be seen? I vaguely remember looking at this years ago.

Thanks,

[dilvoy]

Yes it is. I did it from the side by removing the little side cover. I did it before I installed the injector pump so it took all of two minutes to do the whole job. I'm not shure that you can do it from the top hole without removing the little parts that are in the way, because there is not a straight shot at the hex screw. Maybe with one of those allen wrenches with the groove around the end for a wobble effect would get in there.

[hmrbri]

hey guys,
here's an article i found a while back on the subject.
http://hometown.aol.com/achrismas/myhomepage/index.html
b

[Ted Gates]

Great article for I was going to mention "what about egt?" What should be the egt on a 6.2? Mine might already be running a little rich since she snorts a tiny bit of black smoke on acceleration. I would like to install an egt but would like to hear from others what sensor make they used...

Ted