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Fuel injection snafu

horid_minda
horid_minda
in Fuel Injection

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Posted
comment_548215

Well I recently put a new inline fuel pump in my 1982 280zx 2+2. I put 4 gallons of fuel in it and tried to crank it over it's getting fuel to fuel pump but not past the fuel damper. So my question is what are my options is it possible I'm not getting enough pressure in the tank could the fuel damper be bad if so could I just remove it and run a rubber fuel line straight from the pump to the aluminum fuel lines and cut it completely out. Car sat for 10 years so my thinking is I need to replace entire fuel lines. I cleaned had tank and sending unit with paint thinner put new fuel pump and filter on it but still no fuel to rails any help be greatly appreciated

 

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comment_548216

How do you know it's getting to the damper?  Or through the pump?

The simple test for blocked lines would be to disconnect them and blow through them.  There are no check valves to worry about.  Disconnect at the fuel filter then disconnect at the pump.  If it's not blocked gravity will drain the line so have a container handy.

Might be as simple as having the pump wired backward.


  • Author
comment_548217
How do you know it's getting to the damper?  Or through the pump?
The simple test for blocked lines would be to disconnect them and blow through them.  There are no check valves to worry about.  Disconnect at the fuel filter then disconnect at the pump.  If it's not blocked gravity will drain the line so have a container handy.
Might be as simple as having the pump wired backward.
I pulled the hose that went from the pump to the damper loose and gas came out that was at the pump I pulled hose loose at filter nothing came out I turned the key so the pump ran and nothing still came out I pulled the line from the damper to the aluminum fuel rail under the car loose at the damper and it was bone dry the rubber hoses are clear I pulled them off and blew through them.

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comment_548220
6 minutes ago, horid_minda said:

I pulled the hose that went from the pump to the damper loose and gas came out that was at the pump I pulled hose loose at filter nothing came out I turned the key so the pump ran and nothing still came out I pulled the line from the damper to the aluminum fuel rail under the car loose at the damper and it was bone dry the rubber hoses are clear I pulled them off and blew through them.
 

You didn't say that you ran the pump and saw fuel coming out of it.  I always go for full confirmation, avoid assumptions.

There's not much to the damper.  People do run without it.  But if you're pump is wired backward it won't matter.

Either way, you can remove or bypass the damper just for a test of the lines.

  • Author
comment_548221
You didn't say that you ran the pump and saw fuel coming out of it.  I always go for full confirmation, avoid assumptions.
There's not much to the damper.  People do run without it.  But if you're pump is wired backward it won't matter.
Either way, you can remove or bypass the damper just for a test of the lines.
So pull the line off at the pump and give it a whirl then go from there right on I just assumed cause I had gas coming out when I took the line off it was working

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comment_548222
3 minutes ago, horid_minda said:

I pulled the hose that went from the pump to the damper loose and gas came out that was at the pump I pulled hose loose at filter nothing came out I turned the key so the pump ran and nothing still came out I pulled the line from the damper to the aluminum fuel rail under the car loose at the damper and it was bone dry the rubber hoses are clear I pulled them off and blew through them.

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When you say damper, do you mean to fuel pressure regulator (FPR) on the fuel rail above the injectors or the pulsation damper on the side of the pump? You mention disconecting it from the rail.

Can you run a hose from the pump into a bucket or container and do a run test. That will tell you if its pumping. A normal 280zx pump will pump about 2-3 liters a minutes. If it's wired in reverse it will be about 1-1.5 liter. That can be different with after market pumps,but you can reverse the wires and see if it  pumps more or less.

 

20180429_211020.png

comment_548223
5 minutes ago, horid_minda said:

So pull the line off at the pump and give it a whirl then go from there right on I just assumed cause I had gas coming out when I took the line off it was working

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It might have just been leaking through the pump, backward.  There's supposed to be a check valve that would not allow that, but, as I said, I always confirm.

If you posted a picture or told what kind of pump it was we could give more suggestions.  

  • Author
comment_548226
When you say damper, do you mean to fuel pressure regulator (FPR) on the fuel rail above the injectors or the pulsation damper on the side of the pump? You mention disconecting it from the rail.
Can you run a hose from the pump into a bucket or container and do a run test. That will tell you if its pumping. A normal 280zx pump will pump about 2-3 liters a minutes. If it's wired in reverse it will be about 1-1.5 liter. That can be different with after market pumps,but you can reverse the wires and see if it  pumps more or less.
 
20180429_211020.thumb.png.43b9a9fac028b33c1250aaab8673709a.png
I mean the pulsation damper and I tried a test run at the fuel filter with no luck I'm going to double check everything when I get home

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comment_548229

The original pumps have two different size terminals to prevent reversing the wires. I would start there, check the flow is good and the move forwad from there. Connect the damper to the pump and run damper to a container and test again to see the flow is still the same.

Simple process of elimination.

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