NW KS/ SC ID | todd67648 - 1/14/2023 20:45
It's been a long time since my 6.2/6.5 days. I cannot think what the direct problem may be, but will offer a couple ideas. I believe I had a hard starting 6.2 in the 80's and could not find the air leak. I ended up putting a one way aluminum check valve in the rubber line you speak of (that are showing the bubbles). This helped my problem Another option is look at the fuel transfer pump wiring arrangement. 1988 and newer have an electric pump in the frame rail, that will only turn on when oil pressure is signaled. (A safety device in case of a roll over/crash or similar). For testing purposes, you could wire it key hot and let it pump up pressure for a bit and see if that helps. I know the OBD port has a wire that runs directly to the hot side of the electric fuel pump, but I cannot recall what wire it was. I remember you supplied 12v + power to that port on the OBD port, the pump was live. Good luck.
95 and older electric lift pump had to have oil pressure present to engage, 96+ does too, but does have a prime function that runs the lift pump when the key is turned on, I believe Ecm controlled feature. |
6.5 diesel question for GM Guy or others
