| Author | Message | ||
| J.C.B. (Eagle)
Registered Member Username: Eagle Post Number: 116 Registered: 12-2000 Posted From: 209.183.34.44 Rating: N/A |
I have a DD6V92TA I had an air leak at the cylinder where you adjust the RPM's for full throttle. The RPM's are at 2100 now that the air leak is fixed but I would like to raise it to about 2300 RPM's as it performed better with the air leak than it does now. "No I am not going to deliberately start the air leak back" In the cylinder there are 3 washers about 1/16 of an inch thick and about 5 washers real thin. I need an educated guess as to how many washers to remove and which ones. | ||
| Donn Reeves (Donnreeves)
Registered Member Username: Donnreeves Post Number: 5 Registered: 3-2007 Posted From: 69.115.76.219 Rating: N/A |
I have never seen the setup you are refering to. On all the MUI 6V-92's that I have seen, there is a housing on the side of the governor held on by two bolts.Under that housing there is a large nut that adjusts the no load speed and a theaded stud that ajusts the idle. There is no air or washers involved that I have ever seen. Donn | ||
| J.C.B. (Eagle)
Registered Member Username: Eagle Post Number: 117 Registered: 12-2000 Posted From: 209.183.34.44 Rating: N/A |
This is a Mechanical engine. | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 380 Registered: 7-2006 Posted From: 68.205.165.5 Rating: |
I'm no DD mechanic, but..... My MC9 air throttle cylinder has threads and a locknut, but no washers. Screwing it in until the idle rises slightly, then backing it out about 1/2 turn, seems to provide full throttle when I expect it to, and remain returning to idle. It would seem to me, that removing a couple washers on yours, but be equivalent to running mine in a turn..... For whatever "that's" worth....................... (?) | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 197 Registered: 8-2006 Posted From: 76.168.69.233 Rating: N/A |
JCB, What Donn means by MUI is "Mechanical Unit Injector." Your engine has six of them. I have never seen what you describe either, so this is a WAG. G is for guess, and I can't print what the A stands for and be polite! It sounds to me like you are describing the high idle cylinder, as it does push on the fuel rack. But, it OPENS the rack, so that probably isn't it. Well, after some more thinking about it, and in line with your description of your symptoms, do you have an air throttle? Next question, when did air leak from the cylinder? The shutdown cylinder only has air pressure while the engine is shutdown, with air in the bus, the high idle cylinder is only charged in high idle, and the air throttle only has pressure while the foot pedal is depressed. So, to keep Sean happy, here is a GUESS of what happened, and a SUGGESTION on how to fix it, based on my ownership experience of two Detroit mechanical engines, and several years of running repairs on 50 12V71T mechanical engines: It sounds to me like you are describing an air throttle actuating cylinder, and when you replaced it, it now doesn't move the governor arm all the way to the full throttle position. If you do indeed have an air throttle, and this was the case, have someone floor the throttle, with the engine off, and air in the bus. Make sure that the air cylinder pushes the governor arm all the way to the end of its travel. If the cylinder runs out of travel before the arm gets to full travel, you can legitimately move the washers that position the cylinder? This will give you full THROTTLE, WITHOUT CHANGING MAXIMUM RPMs, which I strongly suggest you do NOT do! HTH+LOL, George | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 198 Registered: 8-2006 Posted From: 76.168.69.233 Rating: N/A |
JCB, I was interrupted in the middle of typing my post, so John got between us. It looks like both of us reached the same conclusion, which is good. Don't move the cylinder in too far, as it will end up increasing the idle speed, as posted above! George | ||
| J.C.B. (Eagle)
Registered Member Username: Eagle Post Number: 118 Registered: 12-2000 Posted From: 209.183.34.44 Rating: N/A |
I do not have an air throttle. I tried to upload a couple of pictures. But that didn't work so I will email them to you as an attachment. There is an air line that attaches to the side of this cylinder and with a cylinder type piston inside the air opening is behind the piston. I ran the adjusting bolt in and out and it did not effect the rpm's what so ever. JCB | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1251 Registered: 12-2000 Posted From: 67.181.189.94 Rating: N/A |
JCB - The cylinder you're talking about is one of two located on top of the governor housing - one is for fast idle, the other is the engine shut-off. If you only have one, and no fast idle, then it's the engine shut-off solenoid. Neither affect the high and low governor rpm settings. Do you have a Detroit Diesel shop manual for your engine? Setting the rpm is thoroughly outlined in DA BOOK. FWIW & HTH. . .  | ||
| Chris Peters (Chris_85_rts)
Registered Member Username: Chris_85_rts Post Number: 29 Registered: 11-2006 Posted From: 66.194.150.45 Rating: N/A |
It is my understanding that max RPM is controlled by the govenor internal to the engine (not really inside the block, just not something in plain view). My understanding is max RPM no load is 2300 and max RPM load is 2150. | ||
| J.C.B. (Eagle)
Registered Member Username: Eagle Post Number: 119 Registered: 12-2000 Posted From: 209.183.34.49 Rating: N/A |
OK guys I dragged out DA book and it is an air operated governor for low and high idle speeds. RJ This one bolts on to the governor toward the front of the coach with two bolts and has an adjusting bolt in between the two bolts. I have ran the adjusting bolt in and out and it does not affect the engine what so ever. The load rpm's is 2100 and slow idle is 650 and fast idle is 1250. I guess I will leave well enough alone. Thanks for everyone's input. JCB (Message edited by eagle on June 18, 2007) |
