Fuel pump not running

[mreperf]

My 97 Seville decided not to stay running this morning. As soon as it started it stalled, and after cranking for about 10 seconds I opened the door an bent down to listen for the pump when I turned on the key and heard nothing. I checked the relay and fuse, both good. I've heard of a plug that can be hot wired to bypass everything to the pump. Does it exsist and where? The car devolped a surge or hesitation under exceleration and when I would lift off the gas a little bit and it would smooth out and excelerate normal. Never got around to checking pump pressure before it died. I did head gaskets, inserts, crank sensors and oxygen sensors while it was out about 20,00 miles ago. Thanks

[mreperf]

My 97 Seville decided not to stay running this morning. As soon as it started it stalled, and after cranking for about 10 seconds I opened the door an bent down to listen for the pump when I turned on the key and heard nothing. I checked the relay and fuse, both good. I've heard of a plug that can be hot wired to bypass everything to the pump. Does it exsist and where? The car devolped a surge or hesitation under exceleration and when I would lift off the gas a little bit and it would smooth out and excelerate normal. Never got around to checking pump pressure before it died. I did head gaskets, inserts, crank sensors and oxygen sensors while it was out about 20,00 miles ago. Thanks

Three days later it decided to start so I brought it to work and put a fuel pressure gauge on and found it as 35 lbs and when i rev it up a little it drops a few lbs. It also gives a code P0231. Probably just need to change the pump. Do you think the lower than norm fuel pressure has to do with surging when excerating or maybe the harder than normal starting when hot (ok when cold)?

[KHE]

My 97 Seville decided not to stay running this morning. As soon as it started it stalled, and after cranking for about 10 seconds I opened the door an bent down to listen for the pump when I turned on the key and heard nothing. I checked the relay and fuse, both good. I've heard of a plug that can be hot wired to bypass everything to the pump. Does it exsist and where? The car devolped a surge or hesitation under exceleration and when I would lift off the gas a little bit and it would smooth out and excelerate normal. Never got around to checking pump pressure before it died. I did head gaskets, inserts, crank sensors and oxygen sensors while it was out about 20,00 miles ago. Thanks

Three days later it decided to start so I brought it to work and put a fuel pressure gauge on and found it as 35 lbs and when i rev it up a little it drops a few lbs. It also gives a code P0231. Probably just need to change the pump. Do you think the lower than norm fuel pressure has to do with surging when excerating or maybe the harder than normal starting when hot (ok when cold)?

The low fuel pressure definitely has something to do with the hard starting/hesitation.

[WinoBot_Beta]

Had that problem last summer.

Was worse on hot days and sometimes couldn't get it to start after the car was warm.

New fuel pump saved the day!

...

but took half of it.

[Cadillac Jim]

P0231 Fuel Pump Feedback Circuit Low Voltage

I did a quick check and Rock Auto seems to have a better variety and lower prices, without the endless list of fuel pumps that won't work on your car.

[bigmoparjeff]

When you have the tank down, I'd invetigate the low voltage to the pump code. A bad pump usually doesn't cause the voltage to drop below normal. GM has a lot of problems with bad connectors at the top of the fuel pump. When you buy a complete "fuel pump module", often they come with a new connector pigtail to splice on.

Jeff

[Cadillac Jim]

The circuit diagram and description in the 1997 FSM, page 6-419, shows that P0231 is set when the voltage across the fuel pump is low. This may not be a bad fuel pump, in fact it sounds like a bad relay. Check the FUEL PUMP fuse (20 Amp) in the engine compartment fuse/relay center, and the fuel pump relay in the same fuse/relay center. The power to the fuel pump relay comes through a PNK wire from the fuse to terminal B3 on the relay connector and goes to the fuel pump on the WHT wire on terminal A1 on relay connector, which also goes to the PCM and is the wire that has low voltage on it to throw the code. The relay coil ground is on terminal A3 of the relay connector. Power for the relay coil comes from the PCM on a DK GRN/WHT wire to terminal B1 on the relay connector.

The code is thrown when you try to start the car and there isn't enough voltage to the fuel pump. You should get a message on the DIC when the code is thrown. This code likely means that the fuse or relay are bad. If it happens in the first year with a new car, many 1997 year model cars, including mine, had a problem with the wiring that may have been a short; if so that would throw the P0231 code and display a message (mine displayed no messages).

If you use a meter to check voltages and grounds, be careful of the WHT and DK GRN/WHT wires that go to the PCM. It's marked static-sensitive, and a cheap or really old meter (read: plug-in VTVM in OHMS mode) can pop the PCM if used on terminals that go to modules. The FSM says not to "back-probe" connectors with meters, which is using meter probes on disconnected connectors that hook up to modules on the other end; you can do this if you are careful that your meter is designed for sensitive solid state circuits and make sure that you and the meter are grounded.

If you do get a new fuel pump, get one that includes the "wiring harness" which is the wires that go into the gas tank, as bigmoparjeff says. At least one of these is included on the list at Rock Auto. If you get a bare fuel pump, get the harness wires separately.