Hey all,

I have had a look through the factory manual but I can't seem to find the answer to my question.

Whats the stock fuel pressure in psi, at the regulator, at high and low vacuum?

And how does it compare to a 2.6 2nd gen?


OR: Mad Lante, what fuel pressure do you use? lol

only differnt figures carby pump pressure
efi pump pressure

find out what regulator you have go from there :nuts:

only differnt figures carby pump pressure
efi pump pressure

find out what regulator you have go from there :nuts:

Hmm, I think you misunderstand me. I'll explain.

I need to know what it should be at the regulator, therefore everything back from that will be at this pressure, meaning/including injectors.

Therefore, basically, I want to know what 1st and 2nd gen injectors should be run at in low and high vac situations.

then you need to know your injectors and their flow rate:redface:

the fuel pressure in is a constant from the pump to the fuel rail

the injectors open and close at that rate as per the ecu

the regulator is at the end of the fuel rail is it not
and acts as a non return valve/or plug in the sink ?

if the regulator was faulty there would be less pressure kept in the line

when working properly
the pressure would be a minimal variation thats prob why no figures are listed

then you need to know your injectors and their flow rate:redface:

the fuel pressure in is a constant from the pump to the fuel rail

the injectors open and close at that rate as per the ecu

the regulator is at the end of the fuel rail is it not
and acts as a non return valve/or plug in the sink ?

if the regulator was faulty there would be less pressure kept in the line

when working properly
the pressure would be a minimal variation thats prob why no figures are listed

Hmmm, nope not a plug.

Say if you get injectors that require a higher pressure, and the current fuel pressure regulator keeps the fuel rail at a lower pressure that the injectors require, it's not going to get the amount of fuel the ECU is telling the injectors to do.

The stock fuel pressure in the first gen is regulated at 196kPa, with an unregulated output pressure of 245kPa - 264kPa. The second gen has an unregulated output pressure around 330kPa, regulated at 265kPa.

With the injectors, one of the main things to consider with pressure is that it does not necessarily mean you will get any better fuel flow through them. If the injectors are designed to run at higher pressure than what they are provided, they will simply not mist as well and as a result may not completely vaporise the fuel, which obviously allows for some fuel to remain unburnt, decreasing performance and economy. If you increase the flow, it is simply to deliver more fuel to the cylinder due to a mod such as increasing the injector size. To handle larger injectors, again the issue as above reappears and may require higher pressure again.

Regulators work using a spring and diagphram that opens and closes as the pressure increases and decreases. The spring forces the valve closed, allowing the pressure to increase. As this happens, the valve opens at a set point and allows the pressure to decrease until the valve closes again. This process continues in a cycle, thus maintaining a constant pressure.

Regulators work using a spring and diagphram that opens and closes as the pressure increases and decreases. The spring forces the valve closed, allowing the pressure to increase. As this happens, the valve opens at a set point and allows the pressure to decrease until the valve closes again. This process continues in a cycle, thus maintaining a constant pressure.

thats the principle of a non return valve....... now dave go work on your TP lol

I know where to put that plug when you visit :bowrofl:

thats the principle of a non return valve....... now dave go work on your TP lol

I know where to put that plug when you visit :bowrofl:

hahaha effectively they are similar things, but a non-return valve does not necessarily have to restrict the pressure - it only has to open a valve to let the flow through unrestricted, and if the flow tries to reverse, close the valve. Very similar to the simple non-return valve on the oil filter, which is just a silicon or rubber flap that opens when the oil pump is running, and closes when the flow stops to stop oil drain-back.

hahaha can't work on the TP right now... at work right now :D

The stock fuel pressure in the first gen is regulated at 196kPa, with an unregulated output pressure of 245kPa - 264kPa. The second gen has an unregulated output pressure around 330kPa, regulated at 265kPa.

With the injectors, one of the main things to consider with pressure is that it does not necessarily mean you will get any better fuel flow through them. If the injectors are designed to run at higher pressure than what they are provided, they will simply not mist as well and as a result may not completely vaporise the fuel, which obviously allows for some fuel to remain unburnt, decreasing performance and economy. If you increase the flow, it is simply to deliver more fuel to the cylinder due to a mod such as increasing the injector size. To handle larger injectors, again the issue as above reappears and may require higher pressure again.

Regulators work using a spring and diagphram that opens and closes as the pressure increases and decreases. The spring forces the valve closed, allowing the pressure to increase. As this happens, the valve opens at a set point and allows the pressure to decrease until the valve closes again. This process continues in a cycle, thus maintaining a constant pressure.

Thanks Dave, I found those yesterday in my factory manual, and also found the settings on the stock FPR's. Now for an aftermarket one, hmmmmz. :)

38-40psi idle no vacc
when you get yours tho chances are you'll probably run a little lower, just keep adjusting it till you find the lil sweet spot

for thos who are interested the stock pump will provide up to 83psi, however i never actually drove the car with this amount of pressure i just wanted to see what it maxed at

stock is 34-35

for thos who are interested the stock pump will provide up to 83psi

cheers mad lante, good to hear from someone that has done the mod!

I was also wondering how high the stock fuel pump could last for, thanks! :)

i need to get somthing a bit more consistant for my fuel presure issues at the moment for my injectors to "mist" properly i have to bypass the vacume to the stock regulator or im lean at < 2000 rpm

Same!

So I just have to floor it all the time just to get the pressure up.