Hey guys,

On my 00 dek I have a hollowed out stock fpr with an Aeromotive (the one with npt threads) afpr.

The problem is: Whenever I turn off the car the fuel PSI drops almost instantly to 0 psi. I saw on my buddies sentra that it does not and he told me something messed up. I want to put in the nitrous, but a faulty fpr could spell out some trouble for me.

Also, my car almost never starts first try, I just let it try and then try again and it turns right on, no problem. I'm thinking this may be from my intake setup or this fuel "problem"....

Hopefuelly my buddy's wrong.

Thanks guys!

 

Well your fuel system should infact hold pressure after the key is off. On my AFPR ive actually noticed i need to let the fuel pump prime the system to start right away like with stock. Not sure why that is but if i just turn the key in one motion from off it will take an extra couple cranks. When i turn my car off my pressure drops little by little like its supposed to. What is your base pressure set to with the motor running idle?

 

43wot 34 idle (or whatever the FSM says, that's how I did it)

What do you guys think could be the problem of the dropoff?

Now I wish I didn't hollow out the stock piece!!!!

 

grounding of the pump? My pressure stays after the idle. Is the vacuum secured on the FPR, no leaks from the fittings? My guess would be the pump.

 

There are no leaks (fuel or from vacuum), and I have not touched the stock pump at all. How would I check to see if its properly grounded?

 

that wouldnt matter, when the cars off the pump is off, nothing to do with that. As long as your getting the right readings when the car is on i wouldnt really worry about it

 

Well you can just check under the back seat, but I was under the impression you had a Walbro.

Is your fuel gauge attached to your FPR or is it remote? I was gonna say if it's not on the FPR, put your stock one back in and check the pressure after you turn it off.

 

have you touched your injectors? Otherwise i would say maybe an injector is sticking open so that after you turn the key off all the pressure in the rail come out that one injector which would cause longer cranking times aswell sense all that gas is in there.

 

The pressure guage is on the port on the front of the fpr.

I don't have the stock fpr anymore either (I hollowed it out to make it an "off-fitting" )

 

Hmmm....didn't think of this one. I did remove the injectors before because of a misfiring that I couldn't figure out. But that was like a year ago.

Would a sticking injector click or no?

How would I fix this? Just take them out and put the ends in injector cleaner for a while?

 

im not sure if it would click or not if its stuck open, if you removed the injectors it is also possable maybe the seal at the rail finally let out on one of the injectors but not bad enough to be spraying gas just enough to release the pressue. You could try cleaning them that way and see what happens if you have the time to do it. If you havent checked the rear injectors for wetness do so first to see if it may be leaking externally rather than a stuck open injector.

 

Ok, will do...You guys aren't thinking at all that this is a malfunctioning fpr?

 

Can some more people give suggestions please!

I really don't feel like taking off the IM again (those stupid ****ing IM support brackets!!!)

 

does your car run rough at all while at idle and do you have a wideband? What kind of gauge do u have on there? I have a POS megan gauge on my afpr and it will read all screwed up like 5psi at idle until i smack it with the palm of my hand then it will jump up where its supposed to be. If you dont have a gauge thats liquid filled i would highly suggest one. I got a B&M and couldnt be happier.

 

This is the afpr I have right now Aeromotive Universal Bypass Regulator, P/N 13301.

http://www.aeromotiveinc.com/product...sub=1&prod=157

I'm not sure if its liquid filled, but it reads fine....It doesn't jump around and definetly doesn't need to be smacked.

I can't see this contributing to the instant drop-off though.

No wideband YET!!!

 

Bumpity bump bump

 

TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT

 

Bump...ttttttttt

 

I have that same regulator. I run my car at 51psi static (all times) with no vac port connected.

I actually bought the 13301 to replace a SARD FPR that was bypassing fuel pressure. So far, my setup works perfect. Holds pressure for quite a while.

When I first installed my 13301, I had cheap fittings from Autozone and crappy hose clamps. My FP would drop right after the pump shut off. I didn't have any gushing leaks, but I still ended up installing high quality fittings and the problem is gone. I did find I had a small leak due to my previously hoky install, but I could never see or smell the leak. I reckon that is what cause my pressure to bleed down. Even a small leak will cause your FP to bleed down, so double check for leaks, and make sure you used good quality fittings and parts.

 

You have to realize that the OP is not using A33B software.


Edit* not really important considering the point you were making.

 

Heh I have the cheap *** brass fittings too heh.

Maybe that's what it is....Do you have your's set up as a return style system?

Thanks for the reply too!!! Definetly helping me out.

 

I had bought some chinese made junk fittings from Autozone. They were labeled "5/16" but they were probably more like 9/32" or 5mm. On top of that, the barbs were not very pronounced, so I had to really tighten the hose clamps. I found that the chinese made Autozone generic hose clamps slipped too.

I ended up buying all new 5/16" fittings, new Fuel Injection Hose (the old stuff was foobered from the generic clamps) and new fuel injection clamps which are pinch-free and designed specifically for clamping fuel lines.

My car is setup as bypass return. My 3.5 engine has just one fuel line, so I have the 13301 bypassing pressure thru the original fuel return line.

BTW, I just stated my FP for reference. I am not suggesting anyone else use 51PSI unless it's needed (A33B).

 

I am not sure that I would consider your issue an anomaly. My car does exaclty the same thing with my Aeromotive FPR. Fuel pressure drops almost instantly after shutting it down. However, unlike you, I have no problem whatsoever when firing it on. It starts immediatly.

Eitherway, I've had this AFPR since back in my nitrous days and have never had a problem to this day.

 

Very glad to hear that you haven't had any problem arise from it.

My cold start issues could very well be from my intake setup, but I didn't think the fuel pressure should drop so quickly.

Either way it makes me feel better about my situation!!!!