Fuel pump running constantly

[latemodelracer2]

What would cause fuel pumps to run constantly when the key is turned on? You can hear them come on with key on and stay running full tilt entire time key is on. Car previously had a return style setup on it but I Have swapped pumps, check wiring on fpdm, back to stock lines, tune is basic email tune for pulley only. On the computer it shows fuel rail pressure at 74. Fuel pump voltage from table shows 15.00. Fuel pump duty cycle is at .50

 

[hotcobra03]

Maybe it's wired backwards,
Pump is running but wrong direction,

Have you pulled fuel line to see if gas is flowing when it's running.

 

[smashedheadcat]

It’s programmed to run full time if the entire fuel pump voltage table is 15 volts.

 

[DSG2003Mach1]

 

[latemodelracer2]

It’s programmed to run full time if the entire fuel pump voltage table is 15 volts.

i flashed a basic canned tune to the car and it didnt change the voltage. Is the voltage table adjsuted deeper in the tune than a basic tune?

 

[01yellercobra]

Where did you get the tune from?

 

[latemodelracer2]

Where did you get the tune from?

I had a extra x4 and used the canned tune it had on it. It does it with the canned tune and the stock tune on the computer. I’ve verified no chip in the computer, double checked wires vs my other car sitting beside it. Just go through swapping fpdm with no change. I’m getting the same voltage on the green wire 11.9, blue with orange stripe 6.5, and the wire red stripe has .03-.05 both cars.

 

[smashedheadcat]

i flashed a basic canned tune to the car and it didnt change the voltage. Is the voltage table adjsuted deeper in the tune than a basic tune?

I apologize for the delay. I’m sorry, but I don’t know what parameters were changed in the email tune that you have. As for depth in the tune, I’m not sure. The fuel pump voltage table is just one of the many things that can be adjusted/modified.

I’d to make sure the fpdm wiring is correct then see if your tuner can build up another basic tune for you.

 

[DSG2003Mach1]

If the pump is running constant with key on it’s either the tune or how it’s wired. Including a possible jumper at the relay

 

[Black306]

With the key off and the FPDM unplugged, check for continuity between pin 3 on the FPDM plug and ground. If there is continuity, you have a short on the negative side of the fuel pump circuit.

 

[NotSatisfied]

Did it run normally before?

If it did- bad relay or ground.


Sent from my iPhone using svtperformance.com

 

[hotcobra03]

E3B025009.pdf

Shared with Dropbox

www.dropbox.com

E3B025011.pdf

Shared with Dropbox

www.dropbox.com

Diagram

 

[latemodelracer2]

With the key off and the FPDM unplugged, check for continuity between pin 3 on the FPDM plug and ground. If there is continuity, you have a short on the negative side of the fuel pump circuit.

All good on this. I have a couple data logs off sct if anyone wants to take a look at them.

 

[Black306]

All good meaning no continuity?

I’ll take a look at data logs.