84 SE 2.5 Fuel Issue (Page 1/1)
Csell2 AUG 10, 10:20 PM
Hello everyone! This is about my fixer upper 84 SE.

Background: The fuel pump died while the car was sitting after getting it back from my local mechanic (who decided that they didn't even want to look at it).

I replaced the fuel pump with one from rockauto (photo related). Which I now once again have pumping noises (runs after key is turned to on, and when the oil pressure switch activates after cracking for a few seconds).

However no fuel is making up to the throttle area; disconnected the fuel filter and just have the line open with nothing coming out. When the line is disconnected near the fuel tank down below there is a good flow when the pump is active.

I checked the line with a helper and throwing compressed air through the line and seems to be no blockage or debris. Additionally there are no fuel leaks anywhere, so I don't believe there are any cracks or failures.


My only hypothesis is that the pump is bad/defective/cheap and isn't able to provide enough pressure to push the fuel up the line. Other than that I'm lost once more, any help or advise is appreciated!
Patrick AUG 10, 10:44 PM

quote
Originally posted by Csell2:

When the line is disconnected near the fuel tank down below there is a good flow when the pump is active.



"Good flow" means little. Fuel pressure required for the 2.5 is 9-13 psi.


quote
Originally posted by Csell2:

My only hypothesis is that the pump is bad/defective/cheap and isn't able to provide enough pressure to push the fuel up the line.



Because it's such a hassle changing the fuel pump in a Fiero, it's always advised to buy a decent fuel pump, not the cheapest one that can be found.

How secure was the hose connecting the fuel pump to the assembly in the tank? The short length of hose that came with the pump was probably also crap. That hose needs to be submersible fuel line.

If the pump is able to pump fuel out of the line closer to the tank, but absolutely nothing comes out of the line beyond the filter when connected (and the filter is good?), I'd suspect a blockage possibly created by a kink somewhere.

[This message has been edited by Patrick (edited 08-10-2023).]

theogre AUG 10, 11:22 PM

quote
Originally posted by Patrick:
That hose needs to be submersible fuel line.

Yup. J30R10 intank fuel hose. https://www.fiero.nl/forum/Forum2/HTML/146240.html and other threads

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