Hello All First time post. I have a Cub Cadet UTV (aka Massey Ferguson MF20MD) with a Perkins 403C engine and CV transmission. The engine is also known as a Cat c0.7. I know that the engine is used in many other vehicles and plant so I'm hoping that someone here may have some thoughts on my problem. The UTV starts and runs fine, but gives out gray/black smoke constantly. More smoke under load, less at idle, but all the time. The engine is otherwise good. Compression OK, injectors cleaned, new filters, no excessive oil or water consumption. I think the engine is over fueling. I also think that previous owners may have adjusted something to try and fix a bad starting problem that I fixed with non-return valves in the fuel hoses. Is there a safe adjustment that affects the fueling over the whole load range of the engine? The other thing that happens is that the engine loses power when pulling away after idling for a few minutes, then it recovers and pulls normally again. Best regards..............Jonathan
Loosing power under load...your anti-drain valves may present restriction, or lift pump check valve(s) may be worn. If it was built without your drain back valves, you've just band-aided the problem. As for fueling, I got this From here https://avsmanual.com/i.caterpillar/i02785739/ You may need to use Google translate.
There is washable screen under here
Overfueling is not really a thing with diesels. If you give it more fuel it goes faster. How exactly were the injectors "cleaned"? Usually you just replace them.
BV.. I was just getting ready to ask that exact question.. If u used a wire wheel to knock the carbon off.. there’s a better than average chance u ruined the spray pattern.. Are these the type that screws into the head.?? & there’s a tiny pin that sticks out of the end of the injector.?? If yes, u definitely ruined the spray pattern..
TPG, I know the 403C well and it is the little Perkins/Shibaura 3 and 4 cyl - very similar to the Isuzu IDI 3 and 4 cyl with PFR pumps. Unless there is a different fuel system for the UTV from the gensets I work on. It is amazing how long they will run badly and smoke, and when you put a new set on you wonder why you waited so long.
Thanks all for the replies. 1. The engine's mechanical lift pump is blanked off and a solid state electrical pump is fitted instead. This is as it came from the factory and is shown in the Cub Cadet workshop manual so it seems correct for the application. The electric pump has been swapped with no effect. I will try to run without the NRVs and see if it changes anything on the power loss, but the smoking was there before the NRVs were fitted. 2. The injectors were cleaned by a local specialist with a good reputation among local tractor and plant guys. I believe he uses an ultrasonic bath and then tests them for flow and pattern under pressure. No mechanical cleaning is involved like wire brushing. 3. The engine runs fine (apart from the hesitation/power loss), it just smokes. 4. I'll try a set of injectors. Thanks again................Jonathan
I was wondering if you tried new injectors i have a cub cadet giving me the same problem