Fuel pump pressure
#1
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So ive been wondering why my 460cc injectors are maxing out at 5lbs. First i checked and verified that my practically new fuel filter is not on backwards. Next i bought a fuel injection pressure kit. I attached it to the line that goes towards the fire wall which i am almost positive that this is the feed line. Turned the car on and went at looked at the gauge while running and it read 0 psi.
![Name: P6040001.jpg
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Next i opened up the fuel tank lid inside the cab and switched the lines to see if i was feeding through the return line. I was not as the car would not start.
![](http://i692.photobucket.com/albums/vv283/SKmetalworks/P6040002.jpg)
Just now i finally got off my lazy sunday *** and went at tested the pressure Directly above the fuel pump and turned the key to the on position and guess what.. only 15 psi for a walboro 190 FP
Is this what its suppose to be?
![Name: P6040001.jpg
Views: 183
Size: 101.3 KB](https://www.miataturbo.net/attachments/megasquirt-18/205335d1501251779-fuel-pump-pressure-p6040001.jpg)
Next i opened up the fuel tank lid inside the cab and switched the lines to see if i was feeding through the return line. I was not as the car would not start.
![](http://i692.photobucket.com/albums/vv283/SKmetalworks/P6040002.jpg)
Just now i finally got off my lazy sunday *** and went at tested the pressure Directly above the fuel pump and turned the key to the on position and guess what.. only 15 psi for a walboro 190 FP
Is this what its suppose to be?
#3
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From what ive heard pressure on stock fuel pump is around 40 psi @ idle.
Heres the 2 pressure i just took for some eyes
Key in ON position
![Name: P6070008.jpg
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Cranking
![Name: P6070009.jpg
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Could my fuel pump be bad? or not connected correctly?
Heres the 2 pressure i just took for some eyes
Key in ON position
![Name: P6070008.jpg
Views: 118
Size: 73.1 KB](https://www.miataturbo.net/attachments/megasquirt-18/205333d1501251768-fuel-pump-pressure-p6070008.jpg)
Cranking
![Name: P6070009.jpg
Views: 111
Size: 73.4 KB](https://www.miataturbo.net/attachments/megasquirt-18/205334d1501251768-fuel-pump-pressure-p6070009.jpg)
Could my fuel pump be bad? or not connected correctly?
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Thanks for the input. Its a little to late to be workin on the car right now. Ill have hit it again tomorrow.
Any idea what the voltage is suppose to be?
Im pretty sure its not leaking although i will double check that
Any idea what the voltage is suppose to be?
Im pretty sure its not leaking although i will double check that
#9
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That said, however, something is clearly wrong with your fuel pump. With the pressure gauge connected directly to the output, you should be seeing 100 PSI, not 10. Could be the pump itself, could be a leaky union between the pump and the rail inside the tank, could be an electrical problem.
Ideally, you want to measure the voltage across the pump itself (one probe from the meter on each of the two wires at the pump) rather than from the pump to ground. Reason is that this will account for any problems in the pump's ground as well.
As ftjandra said, voltage should be within a few tenths of battery voltage.
#10
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So this evening i got my fuel pump out of the tank and saw this
![Name: P6110010.jpg
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Size: 118.1 KB](https://www.miataturbo.net/attachments/megasquirt-18/205290d1501251534-fuel-pump-pressure-p6110010.jpg)
The o ring was visible which was causing a leak
![Name: P6110011.jpg
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Size: 121.4 KB](https://www.miataturbo.net/attachments/megasquirt-18/205291d1501251534-fuel-pump-pressure-p6110011.jpg)
Fuxerd up
![Name: P6110012.jpg
Views: 103
Size: 122.1 KB](https://www.miataturbo.net/attachments/megasquirt-18/205292d1501251534-fuel-pump-pressure-p6110012.jpg)
even fucked up without the flash
![Name: P6110013.jpg
Views: 132
Size: 96.7 KB](https://www.miataturbo.net/attachments/megasquirt-18/205293d1501251534-fuel-pump-pressure-p6110013.jpg)
Used some fuel line and stuck the tit of the FP in it and then jammed it in the hole and was real snug (which i like
) Finished with a little clamp and eureka
65 psi with a leak on the gauge and the fuel cap open
![Name: P6110001.jpg
Views: 103
Size: 78.2 KB](https://www.miataturbo.net/attachments/megasquirt-18/205294d1501251534-fuel-pump-pressure-p6110001.jpg)
Decided to rip out my old IC setup
![Name: P6110002.jpg
Views: 93
Size: 135.8 KB](https://www.miataturbo.net/attachments/megasquirt-18/205295d1501251534-fuel-pump-pressure-p6110002.jpg)
Heres whats goin in
![Name: P6110003.jpg
Views: 108
Size: 122.8 KB](https://www.miataturbo.net/attachments/megasquirt-18/205296d1501251534-fuel-pump-pressure-p6110003.jpg)
Thanks for the help guys
![Name: P6110010.jpg
Views: 97
Size: 118.1 KB](https://www.miataturbo.net/attachments/megasquirt-18/205290d1501251534-fuel-pump-pressure-p6110010.jpg)
The o ring was visible which was causing a leak
![Name: P6110011.jpg
Views: 108
Size: 121.4 KB](https://www.miataturbo.net/attachments/megasquirt-18/205291d1501251534-fuel-pump-pressure-p6110011.jpg)
Fuxerd up
![Name: P6110012.jpg
Views: 103
Size: 122.1 KB](https://www.miataturbo.net/attachments/megasquirt-18/205292d1501251534-fuel-pump-pressure-p6110012.jpg)
even fucked up without the flash
![Name: P6110013.jpg
Views: 132
Size: 96.7 KB](https://www.miataturbo.net/attachments/megasquirt-18/205293d1501251534-fuel-pump-pressure-p6110013.jpg)
Used some fuel line and stuck the tit of the FP in it and then jammed it in the hole and was real snug (which i like
![wink](https://www.miataturbo.net/images/smilies/wink.gif)
65 psi with a leak on the gauge and the fuel cap open
![Name: P6110001.jpg
Views: 103
Size: 78.2 KB](https://www.miataturbo.net/attachments/megasquirt-18/205294d1501251534-fuel-pump-pressure-p6110001.jpg)
Decided to rip out my old IC setup
![Name: P6110002.jpg
Views: 93
Size: 135.8 KB](https://www.miataturbo.net/attachments/megasquirt-18/205295d1501251534-fuel-pump-pressure-p6110002.jpg)
Heres whats goin in
![Name: P6110003.jpg
Views: 108
Size: 122.8 KB](https://www.miataturbo.net/attachments/megasquirt-18/205296d1501251534-fuel-pump-pressure-p6110003.jpg)
Thanks for the help guys
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