If you have a second cable running off the injector pump, it should be for a excess fuel device to help it when cold starting
Don't think they ever fitted anything that flash to the 2.25 diesel, they had hand throttles as atandard to increse the revs when cold manually. On cold winters days they will sound a bit rough when cold. If your landy was converted to diesel like mine chances are you won't have a hand throttle so might need to keep it on fast idle with your foot. The second cable on the pump is the stop cable so make sure that is able to move fully into the run position. If your landy has servo assisted brakes then there will be a buterfly valve fitted on the air intake operated by an overly complicated accelerator linkage. I dont have one so don't know much about them apart from they are not the easyest things to get working right and doubtless a warn linkage could cause it to do funny things.
I think Idle speed on the diesel is about 650rpm I think (with the engine warm and the handthrottle at the min/disabled position). Its easily to ajust as its one of the bolts that limits the accelerator control on the side of the pump (the one the leaver is sprung against, if it doesn't spring onto it properly then that could cause your problem, you'd need to ajust the linkage). The other stopper bolt for this arm is the engine max speed control which should have been set to 4200rpm and sealed in a tamperproof sleve so it doesn't look like a bolt. wether its still sealed will depend on if someones wanted to play with it. Mine used to idle really fast and it anoyed me so I tryed setting it to what the book said (I have an optical tacho) but I thought the proper speed was too low as everything vibrated loads. Think its just below 700rpm now but it sounds spot on.
Make sure your diesel filters are clean, that can make a differance (though usally when under load) and I think there is a gause filter on the inlet banjo to the injector pump too thats probubly never been cleaned.
