420A Help! Fuel pump no worky worky

[Captain miko]

I have a 1999 Mitsubishi Eclipse with a MegaSquirt MS3. I was trying to fine-tune my IAC valve, so I was cycling the keys on and off. I noticed the fuel pump isn't priming anymore. I've changed the pump and tried to manually turn on the pump via the ECU. The relay clicks, but there's no priming, and no noise from the fuel pump.

Thank you.

 

[Justin DuBois]

I have a 1999 Mitsubishi Eclipse with a MegaSquirt MS3. I was trying to fine-tune my IAC valve, so I was cycling the keys on and off. I noticed the fuel pump isn't priming anymore. I've changed the pump and tried to manually turn on the pump via the ECU. The relay clicks, but there's no priming, and no noise from the fuel pump.

Thank you

Find the high voltage side of the relay, and measure if you have 12V input - If so - trigger the relay and check the output side. If no Volts to/from the relay, then no volts to the pump. Look for a blown fuse or circuit breaker.

 

[Captain miko]

Ok I can try that. But where is the fuse location? I've spent 2 days looking for it

 

[Justin DuBois]

On a stock wired car, the fusible link is the main fuel pump fuse, and the MFI relay turns it on.
There is a fuel pump drive connector where you can push 12V direct to the pump to test just the pump

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[steve]

Since you're using a MS3 is it safe to assume this is the 2GNT with the 420A or is the the 2G Turbo that is having this problem?

 

[Justin DuBois]

Since you're using a MS3 is it safe to assume this is the 2GNT with the 420A or is the the 2G Turbo that is having this problem?

Ah, good point - the profile picture is a Turbo 420a - so not stock at all.

 

[Justin DuBois]

Ah, good point - the profile picture is a Turbo 420a - so not stock at all.

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[Captain miko]

Since you're using a MS3 is it safe to assume this is the 2GNT with the 420A or is the the 2G Turbo that is having this problem?

Find the high voltage side of the relay, and measure if you have 12V input - If so - trigger the relay and check the output side. If no Volts to/from the relay, then no volts to the pump. Look for a blown fuse or circuit

Yes its a 420a with an aftermarket turbo. But I don't do wiring haha so I'll try my hardest thank you.

 

[steve]

Just to be clear this was working and you're getting power to the fuel pump relay but not to the pump or are you getting power all the way to the pump but nothing from the pump?

Was it doing the same thing before you changed the pump?

Have you tried jumping pin 8 to pin 2 at the relay effectively bypassing it?

 

[Captain miko]

I haven't test the relay all I know is I can hear the relay clicking when I turn the key to the on position. Honestly I haven't done any electrical testing I've only listened to the relay click and look for fuses

 

[steve]

Do you have a multimeter and do you know how to use it? If not we can help with both.
If you do we can explain the diagram and how to check at each point to diagnose what might be going on.

You do need to answer all the questions that we ask because that's how we can make sure we are asking the right ones.

Just to be clear this was working and you're getting power to the fuel pump relay but not to the pump or are you getting power all the way to the pump but nothing from the pump?

Was it doing the same thing before you changed the pump?

Have you tried jumping pin 8 to pin 2 at the relay effectively bypassing it?

You answered the last one and I assume you don't know the answer to the first so we need to work on that. Please answer the second question.

 

[Captain miko]

Yes i do and I kinda know how to use it.. but hold on what do you mean you can help with both? Lol if I didnt have one would you send me one? And yes to answer your second question it was doing the same thing so that why I changed it thinking that it was a burnt pump but when I changed nothing happen it was still acting the same way

 

[steve]

Yes i do and I kinda know how to use it.. but hold on what do you mean you can help with both? Lol if I didnt have one would you send me one?

Nope, but I'd gladly send you an amazon link if you needed.

 

[Captain miko]

I was able today to test out the relay using a relay tester and the relay seem to be working normally

 

[Justin DuBois]

I was able today to test out the relay using a relay tester and the relay seem to be working normally

If you have power to the relay, and then you trigger the relay, does it read 12 v on the output side of the relay switch? is 12v going to the pump? If you have 12v at the relay, now go check at the connection to the pump. See if 12v is going into the tank. If you have 12 everywhere with the relay on, but the pump does not spin - then finally, the pump should be pulled and tested.