I recently ordered the ultimate fuel system plus a nippondenso pump from rx7store.net. I got everything installed and took it to the dyno. The fuel pressure is at about 42 psi untill i get to the 5k rpm, it drops to 25-30psi. Does anyone know why is it doing that?

By the way, i havent changed the fuel filter since i got the car. Could that be it? aslo, do you recommend a specific filter, or will an advance auto parts filter do it?

Mods:
Street port
microtech ltx12s
midpipe and apexi n1 exhaust
tdo6 turbo with pfs intercooler

Thanks in advance

click here for specs of fuel system

 

anyone?

 

I assume you got a pump with the fuel system. Did you transfer over the o-ring, cap, and sleeve from the stock pump? If your pump isn't sealed to the tube, then it will not hold pressure well.

Also, If you don't know when the fuel filter was changed last, then I would recommend replacing it.

 

yeah i did transfer everything. Am going to change the filter anyways. Now that i think about it, am going to check the fuel pump resistor. It maybe restricting it from getting the full voltage.

thanks for the reply.

 

Definitely the filter, I had a k&n fuel filter and originally thought it was voltage drop, so after I hard wired a relay from the battery and it was still doing it I swapped filters and voila no fuel pressure drop.

Had the EXACT SAME SYMPTOMS, with the nearly identical fuel system

 

Thats good to hear. I hope that the filter is what it is. Is there a specific brand that you recommend?