fuel pump issue

**Fastdak** · 05-21-2016, 04:52 PM

I'm needing some help. I have a 98 trans am and I'm not getting fuel psi.
Checked vats- good
fuse and relay- good
Just replaced sending unit with a new OE.
Can anyone tell me what the 4 wires are. It has a purple, black, black- white, and gray.

**pajeff02** · 05-21-2016, 05:42 PM

I will have to grab Volume 2 from the garage for a schematic -- just probe the connector for power and ground for starters. Make sure you have the key kicked over into the run position when you check for power.

**pajeff02** · 05-21-2016, 05:45 PM

Here it is:

Purple - Fuel Level Sender

Gray - Supply Voltage

Black - Ground

Black/White - Ground

**Fastdak** · 05-21-2016, 06:15 PM

Okay, thank you. I did find out that I was wasn't getting 12 volts after priming. Tried a jumper wire and gave the gray wire 12v. I now have fuel coming to the rails, but will start, stumble, and die. I don't have a fuel press gauge but a friend is bring his over to check fuel pressure. Any advice would be greatly appreciated.

**pajeff02** · 05-22-2016, 02:55 AM

If the battery has been disconnected our cars always run like crap when you first fire them. Mine always stalls and I have to restart it, but then it runs fine. Check your fuses and relays (just swap the pump relay out with another one temporarily). If you do not have voltage back at the pump the issue has to be further up the power supply circuit somewhere.