erratic fuel pressure help!!

[2GFWDbeast]

erratic fuel pressure making it difficult to tune with ecmlink. Anyone have an idea of what it could be. The car is tuned on E85. I have not changed out the fuel filter.

YouTube - 004

 

[3kgt2nv]

what fpr are you using?

 

[Cory-CR]

I'm assuming since there's a gauge present that you have installed an aftermarket FPR?

I would never discourage the change of a fuel filter, but it could also be something going on electronically with the pump that is causing it to not put out a steady flow of fuel.

I'd do some DVOM probing at the pump and see if power going to it is steady or if it bounces up and down as well. Also look up testing for the fuel pump and make sure the readings are in spec.

 

[aba60620]

My first impression would be that your fuel pressure regulator's diaphram has a hole or tear in it, or possibly a clogged fuel filter. Either can cause that condition

 

[3kgt2nv]

Could also be vibration making the guage inaccurate. If the gauge is old and the spring is "tired" it could cause that also.

 

[2GFWDbeast]

I just install a fuel pump rewire kit but it was doing that before. I do have a aftermarket fpr its from bone head performance. Its 4 years old tho. We tested the fuel pump with the ecmlink. when the car was not running we turned on the pump using the ecmlink to see it was flowing right, and it was steady. When the car is on the fuel is all over the place.

On the ecmlink its trying to correct the fuel and its adding and subtracting may to much. Could a faulty o2 sensor cause this?

 

[3kgt2nv]

Is the pump pulling the same voltage with the car running or is it spiking also? If its spiking voltage at the pump thats most likely your issue. Fuel pressure would not fluctuate due to a 02 sensor. it should stay at where its set.

 

[2GFWDbeast]

hmm no i never tested for voltage how would i go about doing that.

 

[3kgt2nv]

Get a volt meter and probe the fuel pump connections with the car running. it should read one constant number. If it is bouncing your getting some kind of draw off the voltage of the fuel pump. if you did a rewire it may be done incorrectly or it may have something drawing power off the same wire.

 

[Cory-CR]

Get a volt meter and probe the fuel pump connections with the car running. it should read one constant number. If it is bouncing your getting some kind of draw off the voltage of the fuel pump. if you did a rewire it may be done incorrectly or it may have something drawing power off the same wire.

Exactly what I was trying to say.

 

[2GFWDbeast]

Get a volt meter and probe the fuel pump connections with the car running. it should read one constant number. If it is bouncing your getting some kind of draw off the voltage of the fuel pump. if you did a rewire it may be done incorrectly or it may have something drawing power off the same wire.

Are there other things that are ran off the fuel pump power to? Or are you just saying other things in general.