1988 Ford Ranger Custom - Fuel Pump not working

[noahc00]

Hello, I'm wondering if anyone has any suggestions on approaching the problem with the fuel pump not turning on because me and my dad are stuck and don't know what it could be.
I'll list below the actions I took first before creating this thread.

Actions Taken Before the Problem Started:

1. Replaced the fuel pump assembly unit - I got the entire assembly unit replaced because the truck was in need of a new one, but the old one was still working fine

Actions Taken after the Problem Started:

1. Replaced the inertia switch - Suddenly the fuel pump wasn't turning on and I looked into it online to see what might be the problem. I found out it was the inertia switch and replaced it. The truck was running well again and it was the best feeling ever knowing that something I tried doing to fix the problem finally worked instead of taking it to a mechanic.
2. Replaced the Fuel Pump Relay - I looked at the fuel pump relay and it was utterly corroded, but somehow still working and I decided it was better to replace it now than have it suddenly die on me when I'm out and about. I feel as though I crossed the wires and after replacing it, I tried to start up the truck, but this was not successful. The fuel pump was back to not working again and I didn't know what to do so I let the truck sit for a while since I got busy with other things
3. Replaced the ECM - I had time and started looking into it again and found that the ECM might be a problem so I bought a plug-and-play from Rock Auto and tried starting the truck but this was also unsuccessful. I was stumped and let the truck sit for a while again.
4. Took it to a mechanic - I finally decided to take it to a mechanic to look at it and they were able to fix it. It turns out the fuse for the relay was bad and the wiring was wrong.

Main Concern:
After the mechanic fixed it, I got it towed home because of the expired tags. I started the truck at the mechanic shop and it worked fine, but when I started it that same day at my house after getting it towed back home, it died on me, but in a way where the idle for the truck started getting lower and lower like as if the fuel pump was slowly shutting off. Eventually, it didn't start again and I was back to square one. That's when I decided to replace the EEC relay today because it was also corroded, but still no success.

NOTE: I'm aware that the recommended thing to do would have been to call the mechanic and take it back to have them look at it because it did occur immediately after they worked on it. However, I'm unable to constantly get the truck towed to the mechanic and the cost for them fixing the fuel pump relay was around $270 . I really don't want to pay that much for them to fix it again when I might be able to work on it with my dad. Plus, taking it to a mechanic takes the fun out of working on it yourself and learning something new that can help others when they're stuck and the same thing.

Next Steps I Plan on Taking:

1. Electrical Tests and troubleshooting - I'm gonna look into other things with the electrical that I can do before doing something bigger like dropping the tank to look at the fuel pump because that's gonna take quite a bit of time and money for me to do
2. Drop the Tank - If the above step doesn't lead to any solutions, I will go ahead and drop the tank to look at the fuel pump
3. Take it back to the mechanic - If all else fails, I will bite the bullet and take it back to the mechanic

Any recommended steps that you guys know of to approach this problem would be greatly appreciated. Also can the fuel pump short out if the wires are crossed at the fuel pump relay?

 

[rusty ol ranger]

Im assuming this is a 2.3L?

Can you hear the pump running? Or are you assuming its not?

First thing i wouid do at this point is check for 12V at the fuel pump.

Does it have 2 fuel pumps? Im not sure on an 88. But 87 and back had a lift pump in the tank (low pressure) that fed fuel to a high pressure on the frame rail. You need 12v to both.

 

[noahc00]

It is a 2.3L.

Before, I was able to hear the fuel pump running, but now I can't hear it run.

It does have 2 fuel pumps. One in the tank and another outside the tank.

Do you happen to know how I would test to see if 12V is at the fuel pump?

 

[rusty ol ranger]

It is a 2.3L.

Before, I was able to hear the fuel pump running, but now I can't hear it run.

It does have 2 fuel pumps. One in the tank and another outside the tank.

Do you happen to know how I would test to see if 12V is at the fuel pump?

With a voltmeter on the hot wire running to the pump

Youll have to have someone turn the key on (dont crank it) as you are hooked to it, because after 5 seconds or whatever the prime period is the relay will cut power to it.

 

[noahc00]

Oh ok, will do. Thank you, sir, I appreciate it.

 

[alwaysFlOoReD]

It's 2 seconds for the cut out. And I believe you can jumper a wire in the obd port to cause the pump to run full time. The port is under hood passenger side near firewall usually buried where you can't see it. There is an article in the tech section on reading codes, it should say how to jumper the port.

 

[rusty ol ranger]

It's 2 seconds for the cut out. And I believe you can jumper a wire in the obd port to cause the pump to run full time. The port is under hood passenger side near firewall usually buried where you can't see it. There is an article in the tech section on reading codes, it should say how to jumper the port.

Forgot about that. Good call

 

[noahc00]

It's 2 seconds for the cut out. And I believe you can jumper a wire in the obd port to cause the pump to run full time. The port is under hood passenger side near firewall usually buried where you can't see it. There is an article in the tech section on reading codes, it should say how to jumper the port.

Thank you as well, I appreciate the assistance. I'll definitely be looking over the article.