Hi

just installed my rising rate fpr in an attempt to richen up my mixture...

Anyways it runs pretty fine just wanted to check some **** before i drive it... lol i have **** all fuel anyways.

1) i left my vacuum hose for the fpr in my garage in brisbane, so instead i put on some of the hose from my windscreen washers (disconnected them). Should this be alright?? it's not as tight as the other stuff but i think it'll hold till i get home, just checking if i should be worried.

2)i set it at around 42psi at warm idle, i had it to around 46psi but it was blowing smoke now i took a photo, is it running rich from idle?? it's humid here (first time i've seen rain in a while as home from brisbane) and there seemed to be some condensation forming... it doesnt really smell to rich. Hoping just waterand ill put it back to around 45... on the dyno it was reading 16:1-->15:1 a/f ratio or something nearly dangerously lean...

3) also should the pressure increase with rpm?? mine seems to a bit but nothing significant...:S i thought it would

Thanks

peace out

here some pics to help explain

The amount of fuel being injected depends on the length of the signal the injectors are getting from the ecu.

By increasing the pressure of the fuel system doesn't cause the injectors to stay open any longer.

So i dont see how by adding a rising rate FPR would help your fuel situation, unless your car is modded in a way that its maxing out the fuel system.
If thats the case then maybe your maxing out your injectors and its time for some bigger ones plus a tune.

The amount of fuel being injected depends on the length of the signal the injectors are getting from the ecu.

By increasing the pressure of the fuel system doesn't cause the injectors to stay open any longer.


nah something in my tune has gone to poo.

Yes the injectors are opened the same length of time but at a higher pressure this means more fuel will enter... except im not sure thats how it works with an fpr as oppose to a larger fuel pump.

Everything i've read indicates the mixture can be altered overall (to a small extent) by running one of these a bit high...

Pressure is a product of flow and restriction. Without flow, there can be no pressure but without restriction there can be no pressure either.

The fuel pump, supplies flow. The fuel pressure regulator restricts the flow and causes pressure to build up.

A FPR is a valve, which is held shut by a diaphram with a spring on the top. From the underside the fuel fills the regulator and once pressure builds to overcome the spring on the other side of the diaphram, it lifts the diaphram connected to a valve and the valve opens. The pressure is released via the valve and the valve closes. The valve sits there chattering away holding pressure perfectly.

If the fuel pump is larger, the valve chatters more but pressure is still held fine.

Adjustable FRP's have a adjustment screw which pushed down on the spring, causing the diaphram to be harder or easier to lift by the fuel pressure.

For more power, you want leaner mixtures by the way hey, richer will lose power.

Have you taken it back to the shop and gone what the ****??? Fix it now

hahahah no matt, it's like 30mins drive away and i'm pretty sure it's down to me or a fault out of their hands as to why its this lean.

Thanks TC but if you read my original post properly you'd see the a/f ratio is around 15:16 not 12:13 as we want...

I have am ecu n dohc conversion so im not on a stocko rich tune thanks

did u take out yur stock fuel reg aswell ??

hahahah no matt, it's like 30mins drive away and i'm pretty sure it's down to me or a fault out of their hands as to why its this lean.

Thanks TC but if you read my original post properly you'd see the a/f ratio is around 15:16 not 12:13 as we want...

I have am ecu n dohc conversion so im not on a stocko rich tune thanks


Have you done a compression test? Fuel pump? Blocked fuel lines?

yeah i comepletely took out the stock fpr.

My alternator belt was loose and then a battery went flat, i dunno what this does to an am ECU, but yeah while it was happening my alarm was going crazy, i'll just get them to check the tune and then move to other things.

I think a fuel pump failure would be more pronounced and catastrophic and fuel lines like injectors i'd expect to see over time. A compression test was done before i recieved the car.

I have to decide whether to get the injectors (i want to do this as i'd say they'd have never been done before) ultrasonically cleaned before a retune... retune would make the cleaning redundant really but also the guy who cleans the injectors can check my a/f ratio and also will clean the build up off my valves for me.

ON a tangent does repco make custom gaskets, dunno where i heard this.

Thanks

also results seemed to have picked up throttle response and some mid range torque, nothing to really write home about

fuel pump won't add any more fuel unless the stock pump can't supply enough fuel. a fpr with a higher pressure will add fuel.

TC is spot on with all of that jazz.

There should only be a problem in the first place if you have changed your injectors over to and higher or lower pressure set and the ECU cant make the adjustments required and it ends up running rich or lean, depending on what pressure injectors you got over stock ones.

GoTRICE: What's the max pressure that thing goes up to? Or what is the model number for that FPR, I'm looking at getting one like yours to go with my new injectors. :cool: