1996 Mr.Pink

[3X00-Modified]

Yes but I know it's not seeing how it was holding pressure fine before and I know this is a common issue with these regulators. Simple test for that is just pinch the return line with pliers and it will hold pressure if the pump is ok.

[99GaGT3X00]

should sell you my adjustable fuel pressure regulator..it's one of those caspers one iirc..always held the pressure for awhile after the car was off

[Asylum]

They should all hold pressure for a little while after the car is shut off.

[3X00-Modified]

I've had a caspers unit and the reason why it holds pressure is because it's just a stock regulator with the top chopped off and the spring and adjuster installed... I've made a few of my own in the past.. LOL... But with my new 6an lines from the body I need to use the aftermarket stuff and not one attached to the rail.

And yes Eric they should all hold pressure IF factory... Not aftermarket ones, they are not designed the same way.

[Asylum]

And yes Eric they should all hold pressure IF factory... Not aftermarket ones, they are not designed the same way.

Well OK!

I just used stock 120,000 mile stuff that GM did a pretty good job of figuring out.

All these fuel issues seem so ridiculous when you have yet to prove the stock stuff won't do the job.

And no one has proven that!

Because no one has tried. Everyone just assumes they have to go bigger and better.

13.47 three runs in a row. 103.76 mph.

Big heads, big TB, big camshaft, ported manifolds, open headers.

You need more fuel that that?

Shawn is not making anywhere near the power mine made, and Jon while you likely are, if not a bit more, just try it.

Now I don't know what Rodney did as far as fuel delivery on the tune, but it was all stock parts.

NOS will add it's own extra fuel if set up right.

STOP making this difficult!

[3X00-Modified]

I guess your missing the fact that I STEAL fuel from the rail for the nitrous so for me YES a larger pump is necessary or highly recommended. Regarding the regulator and lines I'm doing that to avoid heat soak in the fuel I've HAD ISSUES in this area in the past so I don't know what else I need to do to prove that's a bad setup. There is no way to do what I want with a stock regulator or the crap GM figured out for a STOCK engine.

And yes, Bigger cam shaft lots of nitrous... needs way more fuel than what you were running.

LETS not forget the fact that a STOCK 3500 is a deadheaded fuel system... only one line feeds the rail no return off of it... They had started putting the regulators in the tank I believe or somewhere else in the bay but not on the rail.

Don't get me fired up old man!

[Asylum]

ROFFL!!!

Made my night!

[Asylum]

If your NOS is dependent on the fuel rail delivery, then with all that fancy tubing, for Heaven's sake find it a separate fuel source.

You would be surprised how little extra fuel NOS requires. But it has to be constant and there on demand.

Or bad things happen.

[3X00-Modified]

I looked into a stand alone tank but I didn't want to drop over 500 for something made for over 250hp shot.

Right now the nitrous feeds or will feed off the same common outlets on the regulator. It has 4 of what they refer to as inlets/feeds. One is from the tank an the other 3 are for feeding a device so all lines are at the set pressure. One goes to the rail and the other currently goes to a gauge that will eventually T off to the nitrous solenoid. And then there is the one return line that comes off the bottom of the regulator.

Unused fuel does not travel through the rails at all anymore.

[woody90gtz]

Could you use a 3500 fuel rail? I searched it for shits n giggles and it looks like it may have a pressure damper on the inlet where it splits to the 2 rails.

http://www.ebay.com/itm/04-05-06-MALIBU ... ad&vxp=mtr

[woody90gtz]

Ok so I just googled fuel pressure damper to see where you could get one to plumb in and found an interesting article.

http://injector-rehab.com/shop/fpd.html

A fuel pulsation damper is a device used to regulate the oscillation of fuel caused by the injectors opening and closing and smooth this out. Sometimes referred to as a FPD. At this time I do not have a diagram to show you, so you will need to use your imagination as I describe it the best I can. Sorry.

The damper uses a diaphragm to absorb pulses or waves in the fuel. If you could picture what would happen if you were to have a large beach ball in a pool and "bounce" the ball half under the water, let it come up and repeat several times. Waves would form. The injectors opening and closing against the pressure sent by the pump causes the same waves in your fuel system. The damper's diaphragm is used to absorb these waves and smooth the fuel delivery.

Many people say you do not need the pulsation damper, other will tell you that you do. The ones that say you do not need it more than likely either heard of someone or themselves had an engine fire due to the pulsation damper failing. The ones that say you do need it may have heard stories of an injector failing because there was no pulsation damper. The failure of the injector was caused by the fuel hammering the injector so hard that it failed. I have never personally seen an injector in this state (remember we se A LOT of injectors) and still feel this is an urban legend. If you happen to have an injector in this state, please let me know. I would LOVE to test and analyze it.

If you are running an aftermarket fuel pressure regulator, more than likely there are dampening capabilities built into the regulator. I know for a fact that Aeromotive regulator use this technology but I am not sure about others. Mounting the aftermarket regulator as close to the fuel rail as possible will eliminate any need for additional dampening. The Aeromotive units will regulate the flow by creating a stable and smooth flow.

In short, a pulsation damper does serve a purpose, but is not "nesecary". Many cars like the Mazda RX7 are equipped with a fuel pulsation damper that is prone to failing and causing an engine fire. If you plan on retaining the FPD you must keep an eye on it. Replace it BEFORE it fails and you loose your car to a fire.

[3X00-Modified]

The 3500 rail would require shorter injectors or some other mod of the mounting to get it to fit.

And I don't really see a benefit to changing... My rail right now has 6an inlets.. Very easy to plumb this would need another quick disconnect fitting and it points out the front of the intake in a weird spot.

[woody90gtz]

The fuel damper is the benefit I was suggesting, but according to that article it may not be needed. I looked for a universal one with an AN fitting or similar and couldn't find one that wasn't an OEM application. The 3500 rail would just let you use the 3500 fuel system setup as GM intended.

[3400tZ]

I looked for a universal one with an AN fitting or similar and couldn't find one that wasn't an OEM application.

http://www.injector.com/cart/pc/viewPrd ... category=4

[3X00-Modified]

Not sure why a dampener keeps getting brought up because I don't need one. the design of the system and length of lines pre and post regulator is very similar to original and if they didn't have issues to require one then I don't think I need one. Plus I don't see pulsations in fuel pressure to indicate there is an issue.

My biggest problem is the fuel pump prime time is not long enough to start the car without it hesitating badly, I need to turn the key on and of at least twice to fill the system with fuel and then on the third time crank immediately so it's cranking while the pump is running. The only value I found in the ECU for fuel pump prime time apparently does not alter what my setup does. I changed it from 30 to 300 and it was listed at seconds... First off my pump only runs about 3 seconds so I thought maybe it was miss labeled and should have said milliseconds but no dice, it didn't change a thing.

I'm tempted to fall back on the old fuel line/regulator system so I have something that I know will hold pressure after prime to start the car as well as run it just fine and then math out the other setup off the car and maybe install that at a later date.