I have a 1996 k1500 Z71 5.7L vortec motor and yesterday i had noticed that my oil pressure was kind of low, so i checked the oil and noticed that someone had stole my oil cap, so i poured a quart of oil in and went and got a cap this morning. well on my way home i had noticed it was seeming kind of sluggish, i started to climb a hill and i lost all oil pressure and it started to run way ****ty. i got to my driveway and it died, i coasted into the driveway and let it cool down. i checked the oil and it was low, so i just poured a quart in and tried starting it. it turned over then started and died. still no oil pressure. any help would be great i really need it!

 

The oil pressure sensor contains the sensor part for the I/P cluster and switch part for the fuel pump. Since they both seem to agree ("no oil pressure" in the I/P cluster and fuel pump not powered on), it's probable that you actually don't have any oil pressure. Check to make sure the electrical connector didn't fall off the sensor (located next to the distributor, takes three wires colored TAN, ORG, and GRY). If not that, maybe there's a problem with the oil pump or pickup.

 

so update... i change all the plugs. (they needed to be changed anyways) i go it started... with help from the gas pedal, and it said there was like 40 psi on the oil pressure gauge, then it just quit. it died, now it just turns over and over...

 

check the pcm for DTCs, if nothing is present MAKE SURE you have oil pressure, from what your first post said it sounds like to me you have a bad oil pump, but not after your second post.....

 

well now that i think about it it makes sence. no oil no oil pressure. running it without the cap couldve somehow helped get the oil out. and when i added the quart it wasnt enough.. so after it died and i added more oil it said there was once again pressure.. then maybe did the no oil issue destroy the motor? i hope not... it was new this summer.

 

i would change the oil and filter to make sure you have a known quanity of clean oil and clean filter,cut the old filter open to see if there is lots of metal and also what does the oil in there now look like after draining it, what is the oil pressure now?

 

the oil in it right now is black, i know i need to change it.. when i had it started it said 40 psi... im afraid to look in the filter... im almost positive that there is going to to be shards of metal in the filter and in the oil... there was no known knocking sounds. and it still turns over.. so its not froze and its not dumping oil out of the engine so theres no hole in the block.. ill definetly get it in the garage and start working on it though. ill post back here when i get results.