bucking when going into boost - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

spools420a · 07-18-2021, 11:12 AM

UPDATE:

I tested the fuel pressure and here are the results...

With no vaccume line removed it at 43 PSI Fuel Pressure

Revving the engine the psi jumps to 50 psi

removing the vacuum line we see 53-56 psi

adding 10 psi of air pressure we are at 66 psi of fuel.

Pretty sure i'm on the right track to the fix now.My first thought was replae the FPR but giving it some thought Im wondering if a partially clogged fuel filter may be the issue since its on the return line side this would increase fuel pressure and reduce fuel volume correct?

anyways i ordered a z32 fuel filter and a walbro 255lph pump just because the old pump is 15 years old and cant even hear iit anymore when i drive like i used to hear it.

if this doesnt fix issue i will replace the fpr though it didnt seem like the diaphram was torn or anything.also ill look for slight kinks in the lines.

07-18-2021, 11:12 AM	#7
spools420a Zilvia Junkie Join Date: Dec 2009 Location: phoenix az Age: 42 Posts: 460 Trader Rating: (1) Feedback Score: 1 reviews	UPDATE: I tested the fuel pressure and here are the results... With no vaccume line removed it at 43 PSI Fuel Pressure Revving the engine the psi jumps to 50 psi removing the vacuum line we see 53-56 psi adding 10 psi of air pressure we are at 66 psi of fuel. Pretty sure i'm on the right track to the fix now.My first thought was replae the FPR but giving it some thought Im wondering if a partially clogged fuel filter may be the issue since its on the return line side this would increase fuel pressure and reduce fuel volume correct? anyways i ordered a z32 fuel filter and a walbro 255lph pump just because the old pump is 15 years old and cant even hear iit anymore when i drive like i used to hear it. if this doesnt fix issue i will replace the fpr though it didnt seem like the diaphram was torn or anything.also ill look for slight kinks in the lines.