Hello,
I have a '92 Cummins L10 engine with a PT fuel injection pump. The engine is running kind of rough when I give it some throttle. I am leaning toward the fuel system as the problem.
I am thinking that air is somehow getting into the fuel system or the injector(s) maybe bad. I looked from the suction side of the fuel pump to the fuel tank and didn't see any visible fuel leaks. Also, I found that this engine isn't like the smaller Cummins 5.9 engines. All the injectors are inside the cylinder head assembly on this engine. There is a pressure fuel line that goes from the fuel pump to the head and a return fuel line that goes back to the fuel tank.
Here are some questions I am having and would like to hear your opinions.
1) What is a good way of checking that air is getting into the fuel system?
2) I have read that air maybe getting through the aneroid. I was wondering if this engine has an aneroid. If so, where is it located.
3) Is their a test I can perform to determine which injector is the potential problem?
4) Also, what is a good way to remove carbon build up from the injectors without removing the injectors? I was reading a Cummins manual and it mentioned about reverse flushing. Here is what it said:
** Loosen all injector adjusting screws one turn from the bottom or one and one-eighth turns from the set position. Lock with the jam nut after completing the required turns.
** Start the engine and accelerate with maximum throttle from idling to high-10 to 15 times.
** Readjust the injectors to their standard setting.
5) But I don't know where the injector adjusting screws are located. Do I have to remove the valve cover and get to the head assembly to get to these screws? The manual didn't have a diagram of where the screws are located.
Sorry about the long post. I have been trying to troubleshoot this problem and couldn't find a probable cause. I am posting this message as a last resort before I take it to a qualified diesel mechanic.
Thanks for your time and hope to hear from you soon.