I have a 1997 Chevy S-10 4WD/ Auto/4.3; has anyone found that a faulty oil pressure sensor causes the ECM to shut down the fuel pump?
Started the truck cold on a morning a couple of weeks ago, drove about 2.5 miles and it just shut down. Wouldn't start again. Felt and sounded like it was out of gas, so I borrowed a gallon, poured it in and tried again, cranked but would not start. Thought gas level might still be too low somehow so went and bought 5 gallons and a can of cold start. The added gas did nothing, but when I cranked the engine and sprayed the cold start into the air intake, it sputtered and started. Good, thought that was it and drove away another 1/2 mile when it happened all over again. This time no amount of cranking, ether, battery jumps, etc. produced anything. Three hours later we towed it home. I could hear the fuel pump coming on, but no start. I found almost no pressure at the fuel line test port, concluded the filter was probably clogged, changed it, found better volume at the test port, but not much better pressure. Still no start. Changed the pump figuring the problem was either with the pump or the pressure regulator and thought the pump an easier fix. Still no start. Fuel pressure reading at first key on/engine off cycle was about 5lbs. Cycled it again and it rose to about12lbs, again and pressure rose to 25lbs. Did this again and again until at about the 5th or 6th time it arrived at something over 60lbs briefly then fell to 52lbs, where it remained. If it fell at all after that it was very slowly. I had been told that the injector required 61-65 lbs pressure to fire. So I concluded the pressure regulator was at fault. Replaced the regulator, started the truck, checked the fuel pressure again with engine running and it read 52lbs! Fine! Some wrong info; Gave it gas and the RPMs went right up. Problem solved. Thought a test drive was in order. Drove about 2.5 miles, the engine died, and here we are again. It seems to me that something is turning the fuel pump off after the engine has been running a little while. Could it be the oil pressure sending unit is sending a bogus signal to the ECM and triggering this problem?