What are the correct fuel system specs?

Heya guys, what are the correct fuel system specs for a 96 chevy 4.3L vortec c1500?

What's the prime fuel pressure, Idle Fuel Pressure and correct voltage?

I'm reading 60 psi prime, then 55 psi idle and drive and getting 13.3v at the pump power wire

 

1. Ignition "OFF" for 10 Seconds.
 2. With ignition "ON," engine "OFF" and fuel pump running, pressure should be 415-455 kPa (60-66 psi).

Power voltage should be system voltage. 13.3v is good.

 

Ok so my fuel pump is not performing under specs then. I just got this truck back from the dealership, its running great, but I wanted to double check the specs since its under warranty.

They told me it was performing perfectly when they gave me the keys

What should I test and check to find out why the pump is running low PSI, (a brand new pump/motor)

Its got a new fuel filter (PSI was exactly the same with old filter)

Voltage to the pump is good, we know that. So its not being starved for power

Something is burning out all my fuel pumps. They all last about 6 months. This is fuel pump #4, and this time I had the dealership figure it out. They repaired my fuse box and said the contacts were melted and too lose with the relay causing the pumps to burn out.

Now I got a warranty on my pump motor.

All the grounds are clean, I checked them all on fuel pump #3

And here is a look at ol betsy, 380k miles still sounds like a sewing machine

How does she look?

 

wrote:

What should I test and check to find out why the pump is running low PSI, (a brand new pump/motor)

Voltage to the pump is good, we know that. So its not being starved for power

Something is burning out all my fuel pumps. They all last about 6 months. This is fuel pump #4,

All the grounds are clean,
 

You have verified a good POWER feed at the pump (pump running) Now, back-probe the GROUND wire at the Fuel Pump (pump running) and check for voltage. If you have a bad ground, you will read a voltage higher than "near zero", on the GROUND wire.

You have verified a good POWER feed at the pump (pump running) Now, back-probe the GROUND wire at the Fuel Pump (pump running) and check for voltage. If you have a bad ground, you will read a voltage higher than "near zero", on the GROUND wire.

Is there a difference between checking the ground wire and checking the ground bolt? 
 

Ok, so here is my fuel pump electrical system data capture!

Also before you read through the data, understand I am using a Power Probe 4, so hence my inclusion of the (+) and (-) lights. 

 


 

wrote:

Is there a difference between checking the ground wire and checking the ground bolt? 

 

Yes. If the ground WIRE is bad, you will see a good ground at the bolt, but elevated voltage, on the ground wire, at the pump. Suppose there is corrosion in the wire, half way between the bolt and the pump. On the bolt side of the corrosion, the ground is still good. But, on the pump side of the corrosion, you may read elevated voltage. The more corrosion/resistance you have, the higher the voltage will be, on the pump side.

Check the ground as close to the pump as you can.

Yep, that's as close as I could get on the ground wire.

What would happen over time at the two images I shown with all my data, if the connection at pin 86 was "loose"? How would that effect the system over time and change the data above, eventually killing the pump motor in 6 months?

86 is on the control side so if only pin 86 was loose, then there's not enough magnetic field strength to close the load side contacts and there would simply be no power to the pump until maybe the oil pressure switch kicks in.



6 minutes, 20 seconds: low voltage requires more amperage to get the same work done

So I guess the only thing left is to do an amperage test on the fuel pump to see where its at.

ScannerDanner just said these fuel systems are 55-65 psi. So maybe my electrical gremlin is gone! This will be the first fuel pump motor to last over 6 months!