CJM: Ultimate 370z Fuel Pump Thread

[Jayhovah]

Originally Posted by phunk

That pressure spike is the down side.

You wouldn't need a retune if you fixed it. But you don't need to fix it if it's not causing a problem. It come right back down to spec as soon as you give it some gas. But if it's making you idle rich or giving you startup issues you might want to address it.

Phunk... this holiday I have been trying to fix my wobbly idle and thought I might as well do the idle pressure fix... I have pulled the fuel pump and drilled the venturi 4 times now - the last time with a 7/64" bit. Pressure at idle has only dropped to 59psi (and was only ~62psi before I started) and I am hesitant to keep drilling it in fear I may be doing something incorrectly. Is this out of the ordinary? Seems very large compared to the starting point you provide in your tech article. I am drilling all the way through the oriface.

I am running a walbro 255lph and reading the pressure from the mini gauge on my CJM fuel port.

Any advice you can provide would be appreciated! Happy holidays!

edit: Also wanted to mention I have 650cc injectors too.. otherwise the fuel system is stock. I also tried revving the motor up to 3.5k and the fuel pressure only dropped a few psi.