Is my fuel pump dying?

[Guest szlash280z]

I have a 78 Z and I swapped in an 83 Turbo engine.

 

I didn't change to the turbo fuel pump and I think the 78's stock pump is the original one that came off the showroom floor (it looks ancient!)

 

The engine WAS running great and would pull hard through the entire RPM band.

 

Now here is the problem I am having. After 4K and under boost the engine doesn't want to go faster. Hard acceleration under boost in 1st and 2nd gear causes the car to slightly buck. It just doesn't accelerate like it used to. The engine is slow when the boost comes in. I don't hear any knocking or pinging.

 

Here are my test results:

I started the car and let it warm up. With my fuel pressure gauge installed right after the filter, I noted the fuel pressure was 30PSI or so. It was 30PSI before I swapped motors too. I pulled the FPR vacuum line off and the pressure S-L-O-W-L-Y went up to 40 PSI, it would normally jump immediatly to 40PSI before the swap. I changed FPR's and it did the same thing; so it wasn't a slow reacting stuck FPR. I revved the engine all the way to 4K or more while watching the gauge, it stayed at 30PSI the whole time. I pinched the fuel return line and the pressure slowly creeped up to a max of 42PSI. It would jump instantly to 60+ PSI on test's before. If I leave the engine off for a while the pressure bleeds off to Zero. All these symptoms sound like a dying pump to me.

 

What do you guys think?

 

I am going to get a new filter even though this one doesn't have many miles on it.