I want to start the old neon a few days ago. It was only about 5°F out and when I turned the key to the on position, the fuel pump cycled as normal, only it wound down slowly. The car started, but died after about 5 seconds. I thought that it would be pretty straightforward, bad fuel pump, right? Not the case. After checking all the fuses and relays, and checking for 12v+ at the fuel pump connector, I removed the gas tank and fuel pump today.

I figured that before I shelled out $250 for a new fuel pump, I would try to hook it up manually to a 12v car battery. The fuel pump works fine.

I put it all back together, and checked all the fuses and relays yet again. The fuel pump still won't turn on when the key is turned. The only thing that I can think of is that it's not getting 12v negative at the fuel pump. When I tested for voltage at the fuel pump connector, I grounded the negative wire of the meter and only check for positive voltage.

It's freezing cold out and snowing, and I spent 12 hours today taking the tank and fuel pump out. I'm done for the day, but I'll check for 12v negative and positive at the connector tomorrow. Any ideas would be greatly appreciated, though.

 

Just thought that I would add that I've had this car for about 10 years now and have never had a major problem with it. I've had to replace the cam position sensor a couple times and had a cracked radiator at one time, but that's it.

Also, on the off chance that I do not find 12v negative at fuel pump connector, any ideas on what would cause that? With the way this job has been going, my guess is that I will find 12v positive and negative at the connector and still be stumped and stuck

 

Yep, good power at fuel pump connector. Maybe a bad connector? I'm stumped. I'm going to wire in a darn switch and just turn it on and off manually pretty soon

 

If the car doesn't start it will only prime the pump for a few seconds so you need to check it during that few seconds for power. If you show ground on both wires with it plugged in then its a power issue. If you did indeed get power at the pump check the fuel pressure up front to make sure it making it there. If you do get fuel at the rail check injector spray/pulse. Next check for spark.

 

Thank you for the input, but it's definitely at the fuel pump. With the connector disconnected from the fuel pump, and multimeter hooked up to the connector, I get a good 12v for the first two seconds when I turn the key on.

With the connector connected to the fuel pump, when I turn the key on I cannot hear the fuel pump cycle at all. Always been able to hear it in the past.

I took the fuel pump out of the tank, and hooked it up straight to a 12v battery and it ran fine. However, with the fuel pump back in the tank and tank back on the car, I've tried hooking up 12v to the fuel pump at the connector and nothing happens.
I'm leaning toward either a bad connector or bad fuel pump. I would just hate to shell out $250 for a new fuel pump and still have it not work.

Going to remove the tank again tomorrow, and retest the fuel pump and connector. The only thing that I can think of is that maybe the fuel pump is just working intermittently and I just got lucky yesterday when I got it to run off of the car.

Doing the key on and off three times, the only error codes I get are 12 and 55.

 

It was a bad fuel pump. It was only working intermittently. New fuel pump is installed, and it's running again