1998 Chevrolet Blazer 2-Door 4x4 4.3 V6 Automatic 139,xxx miles

I've read the sticky and have done my leak down tests. I'm looking for a second opinion on what my problem is.
My truck is hard to start cold. It USUALLY runs fine once it starts.
I have replaced the fuel pump 2 times, both with AC Delco..the first pump was having this same problem. The pump it has in it now worked fine for 200 miles then started having these symptoms.
At the service port with the fuel pump activated I am getting about 55psi. 10 minute leak down takes me to around 50.
Pressure at the fuel filter output is the same, 55psi. 10 minute leak down took me down to about 45 psi.
I replaced the fuel pump twice and replaced the fuel filter.
The original fuel pump was working just fine other than the fuel level sending unit.
I'm thinking about trying a Delphi pump now. Any suggestions/comments?
Maybe I just got into a bad batch of Delco pumps?

 

Both places that you checked pressure and leakdown came up with nearly identical readings.... which always raises an eyebrow When you tested pressure and leakdown at the fuel filter, did you test it as described in the "How to" thread using the adapter at the fuel filter outlet? Using the adapter forces all fuel flow to end at the fuel pressure tester, with no fuel allowed to the engine. If this is how you checked it, pump pressure is too low. It needs to build 73psi to 108psi, and it must remain above 55psi for at least 10 minutes after the pump shuts down. Provided the pump module is receiving good voltage and ground, and there are no leaks, the pump is at fault.

 

Yes, I used the adapter described in the how to at the fuel filter. Voltage at the fuel pump is the same as battery voltage, and the ground is good.

 

Bad pump. After you replace the pump, inspect what you expect. Check pressure and leakdown at both locations.

 

How did you test the ground? Should be using a voltmeter between the neg term of the battery and the fuel pump ground with the fuel pump running (and hopefully malfunctioning at the time).

 

Good point, Les. Voltage drop can be used for checking both the positive and the negative side of the circuit. Voltage Drop Testing