Bought a '95 F-250 4x4 a little over a month ago, I knew it didn't run, but figured for $1400 I couldn't really go wrong.

The guy I bought it from told me that he had recently had 3 injectors replaced, and that the shop that did the work told him he had 2 more that were on their way out. A couple months after he had them replaced the truck starts running really bad. He figures another injector or two have gone bad, so he parks it until his wife finally makes him sell it. So, I haul this thing home and start tinkering when I can find the time.

1) It only came with one battery in it, so I bought a new battery for the other side. They've been living on the charger since I brought it home. Both batteries are showing over 12 volts.
2) Showing fuel in both tanks.
3) When starting, my scanner shows somewhere between 150 and 180 rpms.
4) After cranking on and off for about 20 seconds the oil gauge will start to read pressure.
5) Buzz test sounded good to me on all 8 injectors.
6) HPOP reservoir is full.
7) Fuel bowl is full, fuel looks clean. I did drain some fuel from the bowl using the drain, and it fills back up after cranking.
8) Glow plug relay makes a loud whine, but it's 80-90 degrees outside, so I wouldn't think glow plugs would be an issue.
9) Pulled the ICP sensor and found oil in the connector. Replaced. Scanner shows around 50% IPR duty cycle when trying to start. I'd like to check exact pressures, but I can't figure out how to on this specific app (car gauge pro).
10) Decided to pull both valve covers and see what was going on. All 8 injectors seem to be spitting oil from the spouts at about the same rate.
11) I am getting some white smoke from the rear of the engine. Assuming my downpipe is probably cracked or rusted, but haven't located the source yet.

Any thoughts on where to go next? And thanks in advance!

 

I would still short the gpr for a minute just to make sure its not the gpr.