Injection pump or pmd
 

i have been trying to find out what contacts to use for getting the reading for a "94" gmc w/a 6.5td, I know, use a paperclip ... to which terminals??? I am trying to figure out if i need an IP or just a PMD, big price difference. One shop said IP, another PMD... I am still a little new to the whole 6.5 kenundrum... HELP