I have a 3QM30 with 5500 hrs. A few years ago the injection pump was leaking
diesel so I took it to a local shop (in Mexico) to have it worked on. I told them not to take it apart, just to replace the 'O' Rings that were leaking.
Unfortunately, the translation didn't go over and they pulled the whole thing apart. They couldn't get
parts, so I had a friend hand carry a set of
seals, barrels/plungers and
delivery valves down from the US. Cost on the
parts was about $500 USD. The lab (if you can call it that) put it back together and it ran well enough. Later in
Hawaii I had it checked out and they said it was pretty tight, so the
Mexico guys did a reasonable job.
The injection pump on the 2QM is very similar to the 3QM (it has the same parts, but two plungers instead of three). I'm not a
mechanic, but if I were you and I suspected the injection pump had a problem I'd have it tested first. This will run you about $100-$150 USD depending on who does it and they will tell you if it needs to be worked on. A lab that can do the testing can probably handle the
rebuild too. The
rebuild is not something to do yourself.
Good luck!