2G Fuel issues - no start, possible bad fuel pump?

[Ashton3D]

I had a theory that adjusting the fuel pressure regulator and trying to start may tell me if it's either the fuel pump bad, or the fuel pressure regulator bad. Adjusting the fuel pressure regulator did not help at all though so I decided to try something else.

What is the fuel pressure output when using the test terminal for the fuel pump?

I decided I'd try to adjust the FPR and then try the test terminal, the results didn't change.

Right when my dad used the test terminal I heard the fuel pump running, then after it took a few seconds and the pump climbed at a mild pace to .5 BAR (~7 psi). I'm not sure if this proves that the fuel pump is weak or if that's all the test terminal puts out.

When trying to start the fuel pressure doesn't climb at all, it stays at zero. It may climb if we kept cranking it for longer but we didn't this time, last time it didn't start no matter how much we cranked it and nothing has changed past me cleaning the FPR.

So, summary. What's the normal pressure from the fuel pump test terminal, and does it mean anything that mine only went to .5 BAR and it took a while to reach there? Is this the sign of a bad fuel pump?

 

[pauleyman]

I had a theory that adjusting the fuel pressure regulator and trying to start may tell me if it's either the fuel pump bad, or the fuel pressure regulator bad. Adjusting the fuel pressure regulator did not help at all though so I decided to try something else.

What is the fuel pressure output when using the test terminal for the fuel pump?

Same as when the car runs.

I decided I'd try to adjust the FPR and then try the test terminal, the results didn't change.

Right when my dad used the test terminal I heard the fuel pump running, then after it took a few seconds and the pump climbed at a mild pace to .5 BAR (~7 psi). I'm not sure if this proves that the fuel pump is weak or if that's all the test terminal puts out.

It does does not prove anything.

When trying to start the fuel pressure doesn't climb at all, it stays at zero. It may climb if we kept cranking it for longer but we didn't this time, last time it didn't start no matter how much we cranked it and nothing has changed past me cleaning the FPR.

So, summary. What's the normal pressure from the fuel pump test terminal, and does it mean anything that mine only went to .5 BAR and it took a while to reach there? Is this the sign of a bad fuel pump?

Not necessarily. Could just be a leak at the pump inside the tank. This seems very indicative the problem is in the tank.

 

[Ashton3D]

Same as when the car runs.

It does does not prove anything.



Not necessarily. Could just be a leak at the pump inside the tank. This seems very indicative the problem is in the tank.

Is there a gasket or something in the tank (on the fuel sending unit?) that would've likely gone bad after sitting in gas for ~20 years?

 

[evil_eagletalon]

Remove the pump and inspect. If not evident issues are found replace it they are under $150.

Idk what “test port” you speak of but if its a fuel pressure test port on the rail then you should be reading way more then 7 pounds. They idle at 43. My car builds 40 while cranking.

 

[Ashton3D]

Remove the pump and inspect. If not evident issues are found replace it they are under $150.

Idk what “test port” you speak of but if its a fuel pressure test port on the rail then you should be reading way more then 7 pounds. They idle at 43. My car builds 40 while cranking.

It's E on this diagram. The official name is "Fuel pump check terminal" you power it with 12v and it activates the fuel pump.

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[evil_eagletalon]

Yea so you are running the pump at all times so ya your pressure is low. Or your gauge is bad. Pull the pump. If it is aftermarket then they are installed to the pump hangar with a rubber section of hose that can split with age. If its original pump replace it consider it an upgrade.

 

[Ashton3D]

Yea so you are running the pump at all times so ya your pressure is low. Or your gauge is bad. Pull the pump. If it is aftermarket then they are installed to the pump hangar with a rubber section of hose that can split with age. If its original pump replace it consider it an upgrade.

It's a Walbro but it's been sitting in fuel for a long time. It was brand new before sitting but I feel it could've gone bad.

I have pulled it a few times, no obvious issues. I had to pull to drain old gas and to replace filter and visually inspect.

Attached is an image of the old filter sock. Guessing it's not a good sign, the internal are probably clogged or something...

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I see no reason why the gauge would've gone bad, I doubt it. It's a Greddy gauge but was also new before sitting and it does function so.

 

[pauleyman]

It's a Walbro but it's been sitting in fuel for a long time. It was brand new before sitting but I feel it could've gone bad.

I have pulled it a few times, no obvious issues. I had to pull to drain old gas and to replace filter and visually inspect.

Attached is an image of the old filter sock. Guessing it's not a good sign, the internal are probably clogged or something...

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I see no reason why the gauge would've gone bad, I doubt it. It's a Greddy gauge but was also new before sitting and it does function so.

If it's been sitting for years now I say yes the pump is likely bad. Or more correctly gunked up from old gas and there is no saving it.

 

[92AWDHX40]

Sitting with bad fuel is definitely not good get that addressed.

 

[steve]

Walbro installs have been problematic since day one. If you're pulled it a time or two it could be leaking right back into the tank like Paul mentioned.

 

[99dsmer4g63]

Be sure the o ring is seated correctly in the fuel pump hanger. Make sure the fuel pump is fastened correctly and firmly.

Change the filter in the bay if you have not already. It’s a lot easier to test the fuel pump with ecmlink than using the check connector too IMO.

-Daniel