OK my car quit running yesterday, started her up drove about two blocks and she died. Checked for fuel pressure and there was none at all. I switched the relays for the AC and the fuel pump to see if it was a bad relay, still no fuel pressure. So I went and got a new fuel pump, installed it and still no fuel presure. figured well maybe the filter is plugged up so I took the line off of the fuel filter and there is no gas comming out of the tank. The car has a half tank, new fuel pump (checked and rechecked to make sure everything is hooked up right) and i am not getting and voltage to the pump. I went and picked up a new relay thinking maybe i over looked somthing, shecked the fuse for the injectors and pump and its not blown. So I am totally out of ideas. Any ideas are gteatly appriciated.
KevinP (Stabby McShankyou) wrote:
and I'm NOT a pedo. everyone knows i've got a wheelchair fetish.
can u hear the pump even come on when you turn the key?
No it doesnt make a sound. I checked the connection where the fuel pump harness plugs into the body harness and there is no power there, which totaly cofuses me because there is pwoer to the fuse and there is a brand new relay in place.
KevinP (Stabby McShankyou) wrote:
and I'm NOT a pedo. everyone knows i've got a wheelchair fetish.
If it's wired the same as a '93, the relay only supplies the "priming" +12volts from the ECM for 2-3 seconds, to energize the fuel pump relay.
This is necessary to start/spin the engine and build up oil pressure to change over the contacts in the oil pressure switch. [Once started, the relay can be removed and the engine will still run!]
[So you won't see the "Normal" 12volts until the oil pressure switch contacts change over.]
Also, if you did not check for voltage in the first 2-3 seconds of switching ON the ignition there will then be a ZERO volts reading [ECM supplied voltage has gone after 2-3 seconds.]
The Oil Pressure switch, which also operates the dash oil light, then supplies the Fuel pump from the ignition switch and fuel pump fuse when the engine is running.
[i.e. If you lose oil pressure the fuel pump is switched OFF by the oil pressure switch contacts switching OFF the +12volt supply.]
If you have, as in a '93, a fuel pump test connector in the engine bay you could use that to test for a 12volt supply to the pump.[It would prove it as far as the engine bay, anyway.]
It should show +12volts to Ground for 2-3 seconds when the ignition is switched ON and then +12volts when the engine is turning over fast enough to change over the oil pressure switch contacts.
Ignore all of this if the later models have a different system
Hope some of it helps
Alont
I tested the lead at the fuel pump for the 3 second power source and there is nothing. I am not sure if there is a check lead in the engine compartment (it's a 2002 LS with the Ecotec). I an going to pull the box out that houses the relay to see if there is a fuseable link in there anywhere that may be burnt. I know there is oil pressure i have a gauge and just when I am cranking it over it reads about 40psi.
Is this possibly a symptom of having a bad oil sender on the enigine?
At this point I am at my whits end. I am usually pretty good with car for being a shacetree mechanic. But this one has me stumped.
KevinP (Stabby McShankyou) wrote:
and I'm NOT a pedo. everyone knows i've got a wheelchair fetish.
ok you checked the relay..
how about the fuse right next to it?????
Yes all fuses and relays are good.
KevinP (Stabby McShankyou) wrote:
and I'm NOT a pedo. everyone knows i've got a wheelchair fetish.
You could try to:-
1. Remove the Fuel Pump relay, insert a test lead from the voltmeter/multimeter to socket #1-other test lead to ground-- switch on the ignition, you should have +12 volts here from your Fuel Pump fuse.
2. If 1. is good jumper the relay base sockets 1 and 4[In my info, 1 is 12 volt input, 4 is 12 volt output to the Oil Pressure sender] then check at the fuel pump connection for +12 volts
3. If still no voltage, leave the jumper in the relay base, then (Note the connections) and remove C and D wires on the oil pressure switch--check for +12 volts wire C to ground
4. If test 3 is good jumper oil pressure switch wires C and D and you should have +12 volts at the fuel pump connector.
[Assuming the wiring from the oil pressure switch to the fuel pump is OK] If you now have voltage the oil pressure switch is defective.
Good Luck
Alont
My suggestion: Check the resistance of the fuel pump to body connector.
