Well, I had a Cummins mobile tech come out and take a look at the engine computer. It turns out some of the "features" defaulted to some very bizarre values. One of the problem values was "Maximum switched engine speed", which had a value of 1205. So, the tech simply upped the value and wala, the engine now revs correctly! I had the tech set some of my other features/parameters as well. The computer also indicates that the engine has already been reprogrammed to its maximum 450hp setting. (sweet!)
Before the tech left he says "so, you want to take it for a drive so I can make sure no other fault codes come up while we are moving"? I of course said "Sure!". So, I disconnected shore power and took off down the drive way. Imagine my complete surprise when the tranny (Eaton Autoshift) was already in 3rd by the end of the driveway! Wow, it works! I can't believe it did autoshifting like it was supposed to! I mean, all that work over the past 5 months and my wiring was correct on the very first try. SWEET! Man, I'm so excited now I almost forgot to slow down for the end of the driveway to make the turn onto the street! We went around the short block and the tranny performed flawlessly. It is in 5th gear before 20mph and all shifts are supper smooth and fast.
We stop in front of the house again and the mobile tech finishes setting some other parameters for me like my diff gears and tire rotations/mile. Then, he offers to ride again while we make sure all the final changes are okay with no new codes being set in the computer. So, off we go for a 3 mile loop. We speed up and high range is selected with no fanfare (5-6 gear change). Then stop for a stop sign. The next shift from low range to high range "hunts". The next stop light and as we accelerate the tranny gets hung up between high and low range and we drift to a stop. I try all kinds of things to get it out of "no mans" land, but no luck. Then in a moment of genius (my own delusion!) I decide to pump down the air tanks. Dumping the air does the trick and after building my air pressure back up again the tranny is happy to go back in 1st. Start going and it hangs up again between 5th and 6th. Dump my air pressure and restart.... Then I decide to not allow the tranny to go to high range and stay in 5th all the way back home. Boy, 5th sure is slow --- about 23 mph at 2200rpm!
So, tonight I tear apart the range select valve and cylinder assembly to find out why it is getting hung up. I have a bad air leak out of the range select valve and I think if I solve that air leak the range split shift should work correctly again.
Of course, after all that I had a hard time going to sleep last night. What an exciting day after all that hard work to have it run the way it is supposed to. Those Jake Brakes are cool too!
Now, due to so many shifts before 20mph it is a little slow off the line. Each shift is fast, but there are still a lot of shifts. Get it up into 6th and higher and put the foot into the throttle and you can really feel the engine come alive. Wow, does it accelerate fast! I can't believe how different that 4-stroke behaves from the old 6v92. It sounds different, accelerates like nothing I've ever experienced and cruises along at 1200 rpms! The one time I had high range without problems I hit 43 mph and the tranny was running in 9th gear with the engine loping along at 1200rpms. It was not lugging at all and when I put my foot into it just a little you could feel the jolt in the backside as it poured on the power. Gotta get that high range valve working right so I can get on the freeway and see how it handles the hills!
