One time I drove 25 miles into town and it wouldn't start after stopping at a parts store. The oil pressure gauge indicated max pressure, so I am sure the jumper was working correctly. Later in the day it will start and run fine. I also got an accurate wiring diagram from an auto elec. Did your pumps have a wire harness, and was it installed? I forgot to mention that I Did find the ground and it was a little worse for the wear so I replaced it and sanded the frame where it attaches it did have continuity so it was not compleatly bad. There did not seem to be any pressure in the fuel lines and the fuel pump did not kick on when I turned the key on.
In both cases though, the fuel pump remains energized through the oil pressure switch until the oil pressure drops below 7psi. I have a similar problem. A new fuel pump replacement for Chevy K2500 is just what you need to alleviate both concerns. I used a vacuum cleaner and rag to clean it. The relay pin numbers did not match with the wiring diagram in the 88-98 Haynes manual I have. My truck has not started on two occasions, most recently yesterday.
They were a lot of fun. Electrical supply to the pump is defective. When I jumpered 87 to 30, nothing happened and the 12v was present on 30 then. I am wondering if it takes a little time for the tank to build up pressure or if I need to double check the o-ring on the fuel pump assembly to make sure it seated correctly. I opened the connections to the fuel filter and let some fuel out.
It is very common for the connection between the harnass and the fuel pump to fail. I hope by replacing the pressure regulator and ground connection my problem will be fixed. What pins at the dash board connector for the instrument cluster could be used to test the sending unit? When the tank is full it reads full and it goes down as the tank level goes down. I am suspecting the fuel pump or fuel pump relay. Electrical problem V8 Four Wheel Drive Automatic 169000 miles Truck will not start on occasion, mostly first thing in the morning. Sure hope that you get this figured out. I would not discount the oil pressure switch.
The sending unit is pretty reasonable on partsgeek. Two days ago it wouldn't start early in the morning, but ran fine later in the morning and has run fine ever since. Runs fine now and no service engine light. Please run some tests and get back to us so we can continue helping you. Putting the bed back on took about 20 minutes with pneumatic tools.
Since I live in San Diego and the truck hasn't rolled over a 100K miles yet, there was just a little dust above the tank. Not sure if this means that it takes 100 miles for the computer to run a complete scan after clearing out all codes. I did manage to get a better wring diagram out of a 1998 Motors manual at the San Diego public library. I hope by replacing the pressure regulator and ground connection my problem will be fixed. I tried to see if there were any fault codes, but the scan tool says all the diagnostic checks had not been completed. I'll post updates as I proceed.
Final thoughts: 1 A complete scan was accomplished at around miles. One note about dropping the tank; there were three lines to disconnect quick-connect fittings and a electrical plug on top og the tank. I have an 88-98 Chilton wiring diagram which has been very little help. I thought maybe a voltage problem since it stated with the old pump some times and others i would have to cycle the key. There are no safety systems for turning off the fuel pump, inertia switch etc.
Is it easier to remove the truck bed to service the sending unit? See post 2: Low voltage, low amperage, low fuel pressure all point to electrical wiring problems. Gm Fuel Pump Relay Testing — Youtube, size: 800 x 600 px, source: i. Also keep in mind that not all vehicles use the oil pressure switch to power the fuel pump. Ok, I have a 1998 chevy k2500 with the 5. I'll replace them for good measure. I would also check pressures after a month and see how they look compared to todays readings.
It starts later and is ok, but seems to crank a little longer before starting. Update 4: 1 I unbolted the bed 8 bolts and disconnected the wires for the lights and the ground wires for the gas filler neck. Not sure if I need to run the truck for a while of if there is a problem with the scan tool. I will double check the connection. If I make up a jumper wire for the pump test connector a head of time at least I will have the capability to get it running in short order. Also, by pinching the return line the psi jumped to the mid 70s before i let it lose.
The tank is only a quarter full. If you choose to change out the plug you will need to splice in a new plug to the wiring harness. Engine cranks but doesn't even attempt to kick over. May want to look into that. All 8 bolts were real easy to get to. If you have noticed your truck jolting unnecessarily after you accelerate and then resuming its regular performance ability, your ride may be suffering from a faulty fuel pump.