I went out today to help Mike (Doogie) figure out why his truck wouldn't start. We were figuring an injector hung open as it won't build rail pressure. Anyway, before I headed out, I checked Mitchell for how to disable the injectors for a compression test. Mitchell says "Disable the Fuel delivery system, by removing the IGN 1 relay". Well, first off, there is no IGN 1 relay. The closest thing is the relay marked 5 and "ECM" under the Diesel list of variables (It IS listed as IGN 1 under the Gas list). Pulled that relay and it wouldn't crank 
. So I gave up trying to figure out what would do the job and we just disconnected all the injectors. What a PITA! So, how the heck do you disable the injectors for a compression test? On the LB7's and LLY's, you can just pull the connectors off the FICM. Not so much on the LBZ's & LMM's.
. So I gave up trying to figure out what would do the job and we just disconnected all the injectors. What a PITA! So, how the heck do you disable the injectors for a compression test? On the LB7's and LLY's, you can just pull the connectors off the FICM. Not so much on the LBZ's & LMM's.
