Fuel pump related fueling issue?

[dpreuss]

So I was working on my car (1990 S13 with SR) the other day trying to figure out my hard cold start situation and I noticed when I started my car the my fuel pump was extremely loud and high pitched. I decided to see how the car drove and it started leaning out under boost....so I then thought it was probably a clogged fuel filter. I have a trick flow 10 micron inline filter so i took it out and blew compressed air through it. Now, I just put this filter in at the beginning of the summer and under a visual inspection it did not look clogged. I reinstalled the filter and started the car - same thing. So I checked my static fuel pressure and it was still good also. So I am stumped...Im thinking about ordering a -6 an union fitting and eliminating the filter to see if that is indeed the problem. I don't think its my fuel pressure regulator because I swapped the stock one from my KA and it didnt help. Do you think it is my fuel pump? Am i pushing it too far? Should I be running dual walbros? Here is a list of mods/ fuel system.
- 15 gal fuel cell in truck
- inline walbro 255lph pump
- -8an fuel line to firewall, -6 an after that
- trick flow 10 micron fuel filter
- 740cc nismo injectors
- nismo adjustable fpr
- GT3076r, running 18psi
- z32 maf
- Power fc with dataloggit
I was also thinking about buying an electronic fuel pressure gauge and putting it in the car so i can monitor it....does anyone know how I could log fuel pressure with the dataloggit? I'm getting really frustrated here so if anyone has any suggestions let me know, I would really appreciate it. Thanks.

[UNISA JECS]

Im sorta in the same boat as you...

http://zilvia.net/f/tech-talk/215167-leaning-out-higher-rpms.html

As far as loging the fuel pressure, what I do with my Nistune is make a custom lookup table in excel with the appropriate voltage vs pressure scale. I know you can buy a fuel pressure sensor and do the same thing you just need to know the lookup scale, or you can figure it out yourself by power the sensor and appling compressed air and recording the voltage it produces at and given pressure reading. Im not sure if the PFC allows you to do the same, haven;t had first hand experience with one.

[dpreuss]

I did some searching and I found that if you do not mount your fuel pump lower than the fuel sump on the fuel cell that the pump may be starved for fuel. Apparently pumps designed for EFI have a hard time pulling fuel put are great at pushing it. My inline walbro is mounted about 3" directly above the sump on the cell. I will try moving it below it tonight. I'm only kind of worried about the pump being damaged. IF it is, should I get another walbro or get something a little higher quality like an Aeromotive tsunami pump? Also, I have the dataloggit software for the pfc, and it does have aux inputs. Perhaps I could call the guage manufacturer and see if they have the voltage to pressure sweep to input into the dataloggit software. Anyway, let me know what you guys think and I will try to post tonight or tomorrow and tell you what I found by moving the pump. Thanks again for the post! -Derek

[japslapsilvia]

are u running a "pre" pump filter?