Scott Y
Well-known member
Summary:
Fuel pump operates normally when started via DSMlink with the engine not running, but starts making strange noises after engine is started. I put about 1000 miles on this configuration, and one day out of the blue the noise started. At first I thought it was something loose in the exhaust.
Fuel System
- intank Jay Racing uberBosch 044
- rewired with 8gauge
- 6an line to stock rail, Aeromotive AFPR, stock return line
- full tank of E85
- tank is spotless inside
Electrical Info:
Voltages
Engine not running, pump engaged via DSMlink
V(battery) = 12.14VDC
V(pump) = 11.86VDC
V(pump running) = 11.39VDC
Engine running
V(battery, engine@idle) = 14.39VDC
V(battery, engine@4000rpm) = 14.45VDC
V(pump) = 14.10VDC
V(battery, engine@idle) = 25.8mVAC
V(battery, engine@4000rpm) = 29.7mVAC
ECU caps replaced in 2000.
Troubleshooting steps already performed:
- Return line removed from tank and fuel directed to jerry can: No change
- Fuel pressure adjusted via AFPR as high as 60 @ idle: No change
- Power line run external to car from battery to fuel pump: No change
- Power line plus new ground from sending unit independent of car harness: No change
- Different known good battery: No change
- Known good battery sitting on floor, connected to (+) & (-) of pump, car harness disconnected from pump: pump runs perfectly! Of course, the pump cannot be controlled via the ECU. The pump was running while connected to the 2nd battery , then the engine was started.
Video of the behavior
Ignore the low fuel warning light, I probably hurt the sensor as I've had the sending unit in and out of the car at least 10 times and it's a wrestling match every time . The tank is known full.
I've been fighting this one for weeks and it is putting the hurt on me.
Fuel pump operates normally when started via DSMlink with the engine not running, but starts making strange noises after engine is started. I put about 1000 miles on this configuration, and one day out of the blue the noise started. At first I thought it was something loose in the exhaust.
Fuel System
- intank Jay Racing uberBosch 044
- rewired with 8gauge
- 6an line to stock rail, Aeromotive AFPR, stock return line
- full tank of E85
- tank is spotless inside
Electrical Info:
Voltages
Engine not running, pump engaged via DSMlink
V(battery) = 12.14VDC
V(pump) = 11.86VDC
V(pump running) = 11.39VDC
Engine running
V(battery, engine@idle) = 14.39VDC
V(battery, engine@4000rpm) = 14.45VDC
V(pump) = 14.10VDC
V(battery, engine@idle) = 25.8mVAC
V(battery, engine@4000rpm) = 29.7mVAC
ECU caps replaced in 2000.
Troubleshooting steps already performed:
- Return line removed from tank and fuel directed to jerry can: No change
- Fuel pressure adjusted via AFPR as high as 60 @ idle: No change
- Power line run external to car from battery to fuel pump: No change
- Power line plus new ground from sending unit independent of car harness: No change
- Different known good battery: No change
- Known good battery sitting on floor, connected to (+) & (-) of pump, car harness disconnected from pump: pump runs perfectly! Of course, the pump cannot be controlled via the ECU. The pump was running while connected to the 2nd battery , then the engine was started.
Video of the behavior
Ignore the low fuel warning light, I probably hurt the sensor as I've had the sending unit in and out of the car at least 10 times and it's a wrestling match every time . The tank is known full.
I've been fighting this one for weeks and it is putting the hurt on me.