Fuel Pressure problems...

[biglipzit]

Hey guys,Ever since i upgraded my intercooler tubing from 2 inch to 2.5 inch with the new intercooler, my boost pressure has risen up to 14psi from the 11psi i use to daily drive it at. At this new boost pressure on hard accelerations i started running lean on the A/F ratio gauge after 4000rpm on any gear but before that it ran rich and gradually decends into the lean. I got a gauge and added it onto my fuel pressure regulator and it showed 60psi and when trying to adjust it i realised the diaphram was fully locked off and no fuel was going through the return line. This was obviously done by the previous owner. So i dropped the fuel pressure down to 43psi and reved the car and after 4000rpm the fuel pressure drops right down to 25psi. So i put the pressure back up to the 60 and revved it and it dropped down to 30psi. I am guessing it may have the stock fuel pump and that the fuel pump is dieing a slow death. I have a supra twin turbo one comming in tomorrow but can anyone verify that this is the prob and that if i change the fuel pump and put my pressure back down to 43psi if this will solve the problem? And at 14psi what should fuel pressure be set at? I did search the forum and didnt find any similar probs.

[Carl H]

could be a damaged FPR.as for stock pump, why would you run a turbo engine on the 240's crappy pump?

[biglipzit]

lol it wouldn't be me but the previous owner and my car is a JDM 180sx with 240 side windows and back plate. It originally had a CA18DET so i don't think it would have the same fuel pump as a ka power 240 but i wouldn't know what it has in it now. How can i tell if the FPR is damaged or not? It held 60psi at 11psi constant.

[JonPowell]

Stop setting the fuel pressure witht he vacuum line hooked up!!!

remove and cap off the vacuum lineset pressure at 35PSIreinstall the FPR and walk away.

whatever the pressure is after that, if you have a good fpr, will be correct.