Picked up a 91 last weekend. Don't know anything about diesels. This is my first one. I read through the 1st generation sticky stuff and left me with more questions than plans. I haven't had time to look over the engine good yet. I wouldn't know what to look for if I did. How can I tell what the previous owner did. He died and his wife didn't know anything other than he worked on it alto.

 

Congrats on your new purchase. Look at the top of your pump If a little plastic cap is still on top it's probably stock. What are your plans for this truck?

 

Just a work truck, but I hear you can get more out of them without getting into trouble.
I read the article on tuning the pump. Are you talking about the cap on the smoke screw? The cap on the power adjustment screw is mia.

 

Yea you can get a bunch of free hp just my tweaking your pump and yea the cap on the smoke screw is what i was talking about it's usually mia if your pump has been turned up at all. If you have read the sticky notes then you probably already know how to turn up your pump. If you have not well everything you need to know about it is in there.