As long as you got a good luminosity probe, particularly of interest is the MT160 which is for the 6.9/7.3 and the GM 5.7/4.3. If it is not cracked you did quite well. It looks like it was well cared for. With that meter you're not totally screwed if the luminosity probe is broken as long as the pulse adpater works, because with the 1480 you can do pulse or luminosity timing. Pulse is what most guys here use, and they shoot for 8.5* BTDC at 2000 rpm per your meter following all the offset directions and whatnot. If you use the luminosity method that lumy probe has to work and you set the timing based on ATDC numbers. Towcat says that 1-2*ATDC at 2000rpm is usually about right and he really knows his stuff. I set mine at 1.5*ATDC at 1400 based on the Haynes book, worked fine. The thing is luminosity may be more accurate it will vary based on fuel quality. The 1.5* number assumes fuel with a cetane value of 47 or more which I felt like I could assume with my B100 biodiesel but a lot of rotgut fuel may be closer to 40 which is supposedly the minimum value in the US. The pulse timing is not affected by fuel quality and variation so that is why many prefer it, plus no expensive, obsolete MT160 to break. Hopefully this will show you where your fuel problem is, I'm betting you'll find your timing is WAY off.