[THEFERMANATOR]

Originally Posted by Skools Out

ok will replace the oil pressure switch when i get home the oil pressure switch is original it has 230,000 miles on it. what do ya mean take out the pump? you mean replace again?

The DS-4 injection pump doesn't like to run hot as it is cooled by the fuel flowing through it as well as lubricated by it as well. They really need a minumum of 2PSI at all times to make them live and function properly. When teh lift pump fails it causees it to run under vacuum and can cause teh injection pump to fail as it will eat up the internal seals. Normally it took out the PMD/FSD before any pump damage occurred though in a stock application. Also pin F of the ALDL plug can be jumpered to 12V+ and make the lift pump run for testing purposes, or you can check it for power while it is running to see if the pump is getting power.

The pic is upside down.