Hi guys, sorry if this post is inappropriate but I'm in here because you guys are more k.knowledgeable on this point and I need a quick answer.
I am pretty sure my fuel pump is on its last legs. Sputtering under load at high rpm, lean at idle, lean when accelerating etc...
An oem pump is 259 cdn, and most dealerships won't sell it separately, they want to.sell the whole unit at 500+. I can het a walbro tomorrow for 69 locally in stock.

So my question is, is the fuel pressure on my car going to stay at 3.5 bar? I'm wondering if it will affect my tune as it is.

Thanks guys

 

yes, that's what the fuel pressure regulator is for

you might need an adjustable one to control it tho, iirc some people didnt need it

 

Ok cool, I had a feeling that we had a regulator but I wasn't sure

 

I have a walbro, and it requires an adj fpr.

 

Any idea why? Is it too much for the stock one to handle?

Bty, where is the stock regulator. Did a quick search on a parts sight and couldn't even find it. I assume Nissan called it something else

 

Its just a good idea when you have a higher flow rate to be able to adjust it.

 

Ok, so I finally found the FPR on the 5.5 gen, and it's a tiny little thing that is built into the Fuel Pump Assy. Nissan doesn't sell it separately. I know it sounds stupid, but is there a write up on where to put an aftermarket regulator?

If the OEM FPR is a gonner, will it stop sending fuel or will it allow the pump to send too much? If it isn't sending fuel because it is toast, a new pump and aftermarket FPR will do nothing for me since the built in FPR is allowing the gas to go back to tank.


I have been searching and getting conflicting results. 3.5 is returnless system so can;t use an FPR, but others say they have done it.

 

You do not need a new regulator. I have been running a Walbro GSS342 for over two years now with the stock regulator.

We have no return line so it is much more complicated to just add a regulator. (5.5gen)

As far as I know, no one has ever even put a different regulator in a 5.5 gen. Most people would probably get the return line off of a 5th gen and convert it to a return system if they really wanted an external regulator, but like I said, it isn't necessary at all. The pressure should stay pretty constant even with the higher flow.


Also, that price seems a bit cheap for a Walbro. Theyre usually around 80. Be aware that there are fake Walbros that even say "Walbro" on it so make sure it is from a reputable place.


A real genuine Walbro will have a slight oily residue on it when you get it. Also, they sound different. There is a youtube video which has an audio clip from both. The fake ones sound like a toy RC car and the real ones sounds more like a pure tone.

 

I have a jobbers account at a local performance shop so I don't pay retail.

 

There's really no reason to get an adjustable aftermarket FPR with a 5.5 gen. You'll have much better precision over fuel delivery by using an Air/Fuel controller.

If the FPR is a goner, you'll know it. You'll either have little or no fuel pressure (stuck open) or black smoke (stuck closed) from a mega rich mixture. There's really not anything to go wrong with a FPR. It's a simple device, just a spring-loaded diaphragm that bleeds (leaks) off excess fuel pressure. The only way to make it go bad is to go through a bunch of fuel with water in it for an extended period of time.

 

Negative. Unless you're talking about a 5hp fuel pump for a cruise ship...The FPR bleeds off any excess pressure no matter the pump unless the pump is so overly-powerful that it can build pressure faster than the FPR can bleed it off which is impossible with normal pumps.

 

Sorry but I have a question about the walbro pump, does anyone know if this would help out with my car being lean. I've got dry plugs but weird thing is my gas mileage sux and I can't figure it out.