Bnr32 Fuel Pump No Check Valve?

[ck_chino]

hey gents I pulled my fuel pump outta my r32 gtr and I noticed that the oem pump does not have a check valve on the outlet of the pump as most pictures on google have. theres a diagphrag looking unit on the body of the pump. Is there any reason mine would be missing? is it a check valve for sure? it seems the oem bnr32 pump has 2 diaphragm looking objects on the pump on on the body of the pump and one on the outlet attached with a couple inches of hose on the way upto the sender body and out to the front of the car towards the fuel rail. what are the 2 diaphragm looking units and most especially is the one on the outlet very important? mind you my car has been running for years with no issues, no problems with hards starting what so ever. seems the pump has been removed in japan before ( I can tell because the level sender retaining ring has damage on it). could it of been upgraded before and maybe the guy returned it back to stock and forgot this check valve maybe?

[scotty nm35]

He probably just upgraded the pump, the 32 is getting pretty old now, no-one relies on 20 year old pumps when tuning.

[GTSBoy]

Pictures are a help.....

[GTRPSI]

You mean the small round can that the line runs through on the fuel pump assembly?

If so its a fuel pulse damnper, its absorbs fuel pump and injector pulses from the fuel, think of it as taking out harmonic pressure spikes and smoothing out the line pressure.

It sort of like those anti hammer devices you can fit to your home plumbing to stop the pipes banging.

Ive read many of the better after market fuel pressure regs have this characteristic built into them.

To find out if you need it, fit a fuel pressure gauge on the line and check to see if the pressure is bouncing by a few PSI......

Most commonly needed OEM on batch fire injectors and large Qty of injectors on 1 rail where you can get the pressure oscillating.

Edit, i might add, i didnt know what they were used for till a few weeks ago when trying to work out my fuel system for our car.

Edited August 28, 2015 by GTRPSI