Have a cat 943 with a black smoke problem. It has been checked out but can't find the issue. The smoke is constant and to me it seems like it bogs a lot. I purchased it from a friend of mine and he had an engine put in the machine. The place that did it charged him $13k to do it. But I found out that they are also a caterpillar graveyard. The only thing I can think is they pulled an engine out of a 953 that I think would have been a turbo engine and put it in this 943 without the turbo. Is there any way to identify if they did that without data plates or stickers. I can't find any and I don't see a serial number on the engine.
Give a Serial Number for the machine and post a load of photos of the engine. Some good photos of the fuel injection pump would also not go amiss.
I think you need to check the underspeed override linkage It is the linkage that comes out of hystat and connects to throttle linkage with throttle in hi idle notch remove top bolt of linkage going to hystat when you pull up on leaver on hystat you will feel a little spring pressure the bolt should go straight in at the begaiing of the spring pressure if it doesnt adjust rod The 943s and 953s the throttle linkage is connected to a bracket bolted to engine flywheel housing there is a lot of play in bolt holes it can really screw up the underspeed override adj
IMHO the first thing the OP should get hold of is a Service Manual, because he is going to need it. Making the adjustments on those hydrostats needs a clear head and clear instructions.
the form is senr3193 systems operation testing and adjusting
I can probably track down a copy somewhere. I dunno about you I'm still a bit worried about the story regarding the engine as described by the OP. All I know about the hydrostats is that the engine should be right before digging into the drive system. I can't help but feel that diving into powertrain adjustments at this point might just be putting the cart before the horse, so to speak. Thoughts.?
I always eliminate engine issues first. Stall tests!
I would bet it would stall ! high idle to zero rpm soon as you pull it in gear If they have you scared of adjusting anything remove the top pin or bolt from under speed override linkage get your self a piece of mechanics wire pull up on linkage till you feel the light spring tension tie the wire to bottom of cab to hold it there Then try the machine ! The under speed valve is what controls the load on engine.The under speed over ride is there so you can move machine at less than high idle,not work it! When its in override pumps do not use the under speed valve to control load on engine! so if you cap the brakes to put tractor in stall the under speed will be the whole way up giving you max imput to servo valves with no chance of dropping the under speed to back pumps off! That is why it is blowing black smoke and lugging
But does it stall hydraucally also? Flutter or anything abnormal. Strange sounds? Different smoke under 1\2 load? All the more reasons to investigate and have all the necessary information to move forward. Hence why I said all of the stall tests would be in order before twisting a wrench on anything else.
Ok here is the deal the pumps in the hystat have way more flow than the poor little 3204 engine can handle at full pressure when tractor is in under speed over ride and you have brakes locked to put tractor in stall soon as you try to put it in drive it tries to take drive pressure to 5500 pounds with the under speed out of the system it will not move the pumps towards min angle ! The poor little 3204 will fall flat on it's face. I'm not calling for anything wild as far as adjustments Adjustments to external linkage is usally where you start. Since the engine was changed I know the linkage bolted to bell housing has a lot of play in bolts and if you pay no att to where it is when bolts are tightened it will be in over ride when its at full throttle.
The machine will still push decent put as I'm pushing I'm constantly having to decrease speed and let the motor catch up. Even without pushing anything if I pull the lever back to full speed it will slowly start to bog and I have to decrease speed as I go to let it catch up. Once I get at half speed or below it seems fine. But still blows black smoke consistently even at idle.
When the machine is operating the drive pressures will be less than the 5500 max why you have to keep moving the control toward slow speed is when it's in over ride the under speed valve is pulled up the whole way it changes the fulcum point on the linkage and gives maximum movement to servo valves that causes servo cylinders to move swash plates towards max flow,flow and pressure equal horsepower when it get to right combination it will start lugging engine. When you get below half speed the comb of drive pressure and flow is most likely less than your engines hp. If the tractor was working with the under speed valve it uses a venturi to make a differance in pressure in the oil flow comming from charge pump it basically monitors engine speed. The two pressures go to the underspeed valve witch change the fulcrum point of the linkage with engine speed allowing pumps to be controled for flow and pressure keeping it at your horse power so there is no lugging . as for the black smoke at idle any one change inner air filter?
Here are pictures of the allegedly new engine. Has about 500hrs run time. All air filters are new
We had a couple 943s that the cust complained about them being weak after we did all we could to hystat to get all the pressures right he still didn't like it we ended up turning the rack up to max cat would allow those tractors would put a black haze out but they ran a little better I still beleve the under speed over ride adj is most of your problem
If it smokes even at a idle I would say that elimates the hydrostat have you checked the timing
Judging from your pictures I would start with a full service of fuel filters, air filters and oil change.
it goes back to what the @orangepeanut said in the first post - "he had an engine put in the machine. The place that did it charged him $13k to do it. But I found out that they are also a caterpillar graveyard. The only thing I can think is they [might have*] pulled an engine out of a 953 that I think would have been a turbo engine and put it in this 943 without the turbo." * - my opinion I have zero practical experience with these hystat loaders but IMO it would be sensible to eliminate any possibility that the engine is the problem before proceeding further. I may be wrong in that assumption......
Someone in this thread has eliminated an engine problem
I know it looks pretty dirty but all that was done 100hrs ago. The job it was on was very dusty. It was doing the same thing before and after the service
I need to dig into the differences between the engine arrangement for the 19Z and the one for the equivalent model of 953 a bit more. I’m sure it is likely to be not as simple as just a fuel injection timing change between the two. I would bet money that the internal fuel injection pump/governor settings could well be different, possibly even different hard parts in the FIP. Additionally the injector nozzles could be different. I will investigate and report back.
I have no hope for you people pulling one pin wiring over ride linkage up and trying it
I will try this
Welcome back Bluox!
Did you work at Murrysville?
yep
Fred? I was out there a year on the other shift I do believe
yep again
We have two problems going on here IMO. 1. An underspeed problem. May or may not be caused by a linkage adjustment OR an engine RPM issue. 2. A black smoke problem. The engine should not make a lot of black smoke*, no matter how much or how little load it is under. *It may make some smoke at startup or under sudden acceleration.
The 3204 in my 931B is just like Cmark says, black smoke sometimes when starting or quick acceleration after changing direction. Machine has the throttle on the shifter so very easy to decelerate when changing direction. My machine has 3 ring pistons so 2 ring pistons may have a little more smoke. The engine in the OP's machine is a higher HP version based on the larger oil cooler.
I think he might have passed.