Got in the ol Neon the other day. It fired up at first and then completely died. Cranked it over a few more times and nothing. My initial felling is the fuel pump has gone out.

Today I check the pressure port on the fuel rail and it confirmed my initial feeling, zero fuel, not even when the engine is cranking.

So I'm wondering if possibly I got lucky and it's the fuel pump relay? My Chiltons manual hasn't been much help in troubleshooting the fuel pump relay. I do have a chassis electrical schematic, but no numbers to reference.

With my trusty amp clamp, I can test continuity on the terminals and find I do have continuity between terminals labeled as 87a and 30.

What does this mean and what can I do to further isolate the Fuel Pump Relay?

Thanks!

 

Well, I finally got around to replacing the fuel pump. Went with a Spectra Premium replacement I bought from Rock Auto. Had to drop the tank which wasn’t too bad. After I got it all back together, I turned the key to accessory and heard the pump prime, win one. Then I started the car and confirmed the correct fuel pressure at 49 psi, win two. The only issue is the fuel gauge is pegged at the full mark. Great! Is it ever possible to be three-for-three with projects like this? Just wondering if filling the tank and driving the car might help lubricate and loosen anything up that might be stuck? Everything seemed to work freely when I installed it.

After a while, I took the car on an errand. Going off memory, the fuel tank is around 1/3 full, so plenty room for fuel slosh. During the drive I made some erratic maneuvers to see if that would do anything to free the fuel level sensor if that is the issue. It didn’t do anything. When I got back home, I decided to check the resistance of the old sensor which was 69.3 Ohms at the top of the sensor stroke. As the sensor drops to the bottom of its stroke, the resistance goes up exponentially until my meter won’t read the greater resistance, my meter is just an amp-clamp, nothing fancy. So I compared the reading of the old sensor to the new one. I measured 71.0 Ohms on the new sensor still installed on the car. So, I’m thinking this may be more evidence the fuel level sensor may be stuck at the top of its stroke. Still waiting to hear from Spectra to see what they might advise me to do.

(A) Will I have to remove the pump and inspect the sensor function further?

- OR -

(B) Should I first try to top off the fuel tank to see if that will work to budge the float loose?

Ideas?

 

I would go with B. Is the fuel gauge the only issue on the cluster? You could try reflowing the connections in the back.
https://dodgeforum.com/forum/1st-gen...er-repair.html

 

Who knows but I really doubt it's the cluster or the wiring. A couple years ago I did have random issues with the whole cluster in that all the instruments would stop working altogether. I took out the cluster and had a friend that owns a computer shop solder up a few solder joints on the cluster printed circuit board as shown in your link. After that, no issues.

So the whole cluster works fine now, it's just the fuel gauge stokes to the top of the full mark when the key is engaged. Plus I had zero issues with the fuel gauge before I replaced the fuel pump assembly.

Also, knowing the resistance of the old sensor at the top of it's stroke (69.3 ohms) compared to the resistance of new sensor (70.0 ohms), makes me think the new float level sensor is jammed at the top of it's stroke.

Right now with 1/3 tank, I should be able to measure resistance of the float level sensor in the 100s of ohms as resistance increase as the level drops. But instead, I'm reading 70 ohms.

 

Could be secend gen fuel pump . If I recall they read backwards full when empty empty when full. But I could be wrong.

 

Well, today I worked up enough ambition to take out the pump again. Had the darn thing out in about 15 minutes and the problem was found immediately. The fuel level sensor which is supposed to be attached to the float rod with three plastic clips had come loose. Either it didn’t get properly attached at the factory (China) or it came loose during shipping. That’s all it was and it feels great to be done.