| Author | Message | ||
| Buddy Matthews (Bud4104)
Registered Member Username: Bud4104 Post Number: 10 Registered: 2-2007 Posted From: 76.107.218.199 Rating: N/A |
I just got another 4104 the previous owner did not seem to know much about the engine. I have found that the rack will not move - Does anyone know the best place to start looking for the problem. I removed the shutoff cylinder and now I am thinking disconnect the governor from the rack - if it still does not move start looking for stuck injectors? | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 631 Registered: 10-2006 Posted From: 72.66.179.36  Rating: N/A |
Have you taken the valve cover off? You should be able to move the rack by hand and see what is working or not. | ||
| Tim Hoskinson (Tdh37514151)
Registered Member Username: Tdh37514151 Post Number: 256 Registered: 9-2004 Posted From: 65.25.139.50  Rating: N/A |
Hi has this bus been sitting for a while? If so it is quite common for moisture to accumulate just under the valve cover and rust the small rack and pinion gears in the injectors as well as the pivot points of the linkage. I have seen this many times on old heavy equipment that sits for long periods of time. In some cases you can remove the valve cover and lube the racks and linkage with a good penetrating oil to free the up. If the racks are badly stuck you may have to replace the injectors. Best of luck Tim | ||
| Merlin Westphal (Merlinpv)
Registered Member Username: Merlinpv Post Number: 3 Registered: 1-2009 Posted From: 75.244.238.58 Rating: N/A |
Injectors are frozen only way to cure that is rebuild them as there is no lube in the diesel anymore this kind of thing will happen if they sit idle for long periods. | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1221 Registered: 12-2000 Posted From: 74.4.63.215  Rating: N/A |
"Injectors are frozen only way to cure that is rebuild them as there is no lube in the diesel anymore this kind of thing will happen if they sit idle for long periods." This happened to a 102A3 that was at my place. He had injectors & bearings replaced. The bus was only driven about 60-70 miles after the rebuilt injectors were installed and sat at my place for about 2 years. When it would not start we pulled the valve covers and found stuck injectors on both heads. So, those rebuilt injectors with 60-70 miles on tham had to be rebuilt again. Jack | ||
| Buddy Matthews (Bud4104)
Registered Member Username: Bud4104 Post Number: 11 Registered: 2-2007 Posted From: 204.9.32.4 Rating: N/A |
Thanks for all the info. I have pulled the valve cover and the control tube will not move. I did put penetrating oil on the racks so I'll go see if that did anything tomorrow. I am thinking if the control tube still won't move, I could remove it and see if it is one or all injectors that are stuck. Then I just have to fix the problem | ||
| Jim Blumenthal (Jimblu)
Registered Member Username: Jimblu Post Number: 13 Registered: 11-2008 Posted From: 141.156.33.61 Rating: N/A |
But try the easy inexpensive things first. There is a single cotter pin and clevis pin that attach the rack to the governor. No adjustments necessary if all you do is remove/replace the pin and move the rack. Do not crank the engine with the governor disconnected unless you know what you are doing. It could run away. | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 850 Registered: 8-2006 Posted From: 74.32.83.4 Rating: N/A |
Remove 1 fuel line on each injector and fill with alcohol or acetone disconnect the rod from the governor like Jim said put a pair of vise grips on the tube by the yoke move in back and forward easy and they will break loose the products above will evaporate no need to worry about the engine running away when you start it. good luck | ||
| Jim Blumenthal (Jimblu)
Registered Member Username: Jimblu Post Number: 15 Registered: 11-2008 Posted From: 141.156.33.61 Rating: |
As long as you reconnect the governor and the rack is at idle! Make sure the shut down shutter on the blower is working. If you don't know what run away means, you don't want to find out.  A Detroit is not like a gas engine with a carburetor. (Message edited by jimblu on February 12, 2010) | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 851 Registered: 8-2006 Posted From: 74.32.83.4 Rating: |
people do it different Jim when I start a new rebuilt I never connect the governor up I always control it with vise grips on rack. It is a common practice the world of 2 strokes DD good luck | ||
| Jim Blumenthal (Jimblu)
Registered Member Username: Jimblu Post Number: 16 Registered: 11-2008 Posted From: 141.156.33.61 Rating: N/A |
I'm not saying something is not the correct way, just something to not do if you don't know what a runaway Detroit is. I was working on another mechanics mess recently and was glad I had freed the shutter. It had been stuck. | ||
| jim bullard (Jimatcat)
Registered Member Username: Jimatcat Post Number: 1 Registered: 12-2009 Posted From: 75.223.240.36 Rating: N/A |
identify the fuel lines on the head... 1 will come in from a filter and the other will retuen fuel to the tank... remove both... get a small 12 volt inline fuel filter, with appropriate hoses to plumb into the head... buy a gallon of laquer thinner... pump as nesessary, tapping on top of each injector with a small hammer.... eventually ( like after 15 minutes of circulation) the gunk that has an injector stuck will "melt" out and your rack will be free... pump diesel thus now, replace the hoses and start the engine... have a pair of vicegrip pliers on the rack to contol it, in case you need to kill the engine... done this several times to engines that have been sitting... works every time... | ||
| Jim Blumenthal (Jimblu)
Registered Member Username: Jimblu Post Number: 17 Registered: 11-2008 Posted From: 141.156.33.61 Rating: N/A |
That sounds worth trying, be aware the injectors have very fine metal screen filters in them under one of the jumper tubes. They can clog and severely restrict performance. Use a good diesel filter, not one of the glass strainers for a car or outboard. You test them by removing the return jumper and cranking the engine. Fuel should gush across the engine compartment. If only a few inch squirt comes out there is a problem. I wouldn't check them with lacquer thinner in the injector though, it comes out at 50PSI and doesn't provide lubrication. As always, use caution with flammable materials! (Message edited by jimblu on February 12, 2010) |
