No fuel pressure when starting

VADER

Little engine that could
Like the title says, I go to start, and pump primes, but gauge directly on fuel rail shows no pressure and car will just crank. Obviously it won't start due to lack of fuel.
A little background. This is the time starting since replacing the fuel tank and the starter. I did unplug the fuel pump harness at the back, but did not disconnect the fuel lines. I have added about 5 gallons into the tank.
The mini starter does seem to work and crank the motor. I am thinking maybe I have a pinched fuel line but also wondering if the starter wires might affect this if not tight enough, or maybe someone I missed one, but I don't think I did.
I never had any issues with pressure before.
Thanks
 

TexasT

Texas, Where are you from
Are you sure you hooked the lines on top of the sender back where they need to be? If it is sending fuel somewhere else it isn't going to the rail.
What about the oil pressure sender, is it In good shape and functioning?
I see where you didn't disconnect. Did this car run before the tank replacement?
 

Jerryl

Tall Unvaccinated Chinese Guy
Not a whole lot of detailed info, for detailed response. Here is some speculation from what I understand as "pump runs but no rail pressure":

*Hoses at hanger reversed.
*Pump polarity reversed.
*In tank hose leaking.
*Defective pump.
 

VADER

Little engine that could
sorry, I left out some info. I can access the fuel pump from the top so I just removed the ring and let it sit in the trunk. I just have to unplug the Hotwire but I don't undo the fuel lines. I haven't started in some time though. It wouldn't start but the starter wasn't cranking over so I replaced it.
 

ScottHeidinger

Active Member
What Hotwire kit? The recent Hotwire kits I’ve used use the stock wire harness to trigger the fuel pump relay in the back of the car. If you hear the pump run but don’t get pressure at the rail check the polarity at the pump. Some of the kits have the polarity backwards on the pump to harness connector. You should be able to take the grey wire in the harness by the alternator and test the pump by applying power to that jumper. Putting voltage to the grey wire should trigger the fuel pump.


Sent from my iPhone using Tapatalk
 

Anthony P

sharing knowledge with those who care to listen
^^^^what Scott said
 

Attachments

  • Tach(GRN) & Fuel pump primer connections.JPG
    Tach(GRN) & Fuel pump primer connections.JPG
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VADER

Little engine that could
I am revisiting this, first chance in some time to work on. My battery is low at 10.5 volts right now, I need to charge it. I ran a voltmeter, and I am getting same voltage up to relay, but after relay it goes to 6.5 . I put some deoxit on it since the harness had corrosion. Fuel pump wires in tank look ok. I haven't tried the jumper yet, but I question the relay.
Also, would the starter connections gave anything to do with the pump if they are loose?
 

VADER

Little engine that could
So, finally got fuel pressure, it was the in tank hose right at the pump itself as someone suggested above. Still trying to start it though.
 
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