kossykarl

hi chaps just a couple of questions for the knowledgeable ones amongst you - thanks

car is 4x4 saffy cosworth green top stage 1


1 whats the best way to test the fuel pressure ( before or after the regulator)

2 i know it should be 4 bar at idle but should this increase with revs or should it be constant


has anyone fitted a fuel pressure gauge inside their car if so how did you connect it to the fuel line.


i`m sorry if these questions seem dumb but i would rather look stupid and ask than risk buggering something up.

cheeRS karl

alan rainbow

fit gauge between regulator and fuel rail 4 bar at idle is high who as advised this

kossykarl

sorry my mistake , graham goode web site states 3 bar at idle.

cheers karl

cossie604

iTrader: (2)

lol agreed, 4bar is a tad high (lol had to use that smiley cos its great) Off top of my head I think fuel pressure should be between 2.8 and 3.3bar

2001ode

iTrader: (1)

Hi,

Basic fuel pressure is 3.5 bar. (running engine and hose disconnected from regulator or fuel pump running alone)
If you are on idle, inlet pressure is - 0.8 bar (common value) and your fuel pressure should be 3.5 - 0.8 = 2.7 bar
If you are on charge, ie with stage 1 EPROM with 1.1 bar TC pressure, your fuel pressure should be 3.5 + 1.1 = 4.6 bar.

Regards.
Claude

july1

iTrader: (1)

I've fitted a fuel gauge on my escort to achieve it have replaced the plastic lines by braided lines and by the way screwed a T piece to fit the gauge (expansive but definitely the right way to do it.
Another possibility is to weld a bung on the rail to fit the transmitter or the gauge
If you wanna fit the gauge inside you need to supply an electric one (with a transmitter so no fuel inside the car) mechanical ones are cheaper but shouldn't be fitted inside.

cossie604

iTrader: (2)

So roughly then, do you raise the fuel pressure say 1bar for every 1 bar of boost increase from standard?? At what sort of pressure would injector lock kick in at?? Is a cosworth fuel regulator progressive with boost increase?? Sorry for many questions but I like to learn

2001ode

iTrader: (1)

As I say, fuel pressure is in direct relation with inlet manifold pressure, and constantly change, as manifold pressure.

Sorry for this pic of fuel regulator, in french.



Regard

kossykarl

checked fuel pressure with gauge - only got 2 1/2 bar at idle and 3 bar with vac pipe removed- fitted new regulator but still the same could it be a weak fuel pump that is causing the drop in fuel pressure and causing car to run lean ??

cheers karl

2001ode

iTrader: (1)

Hi,
2 possibility :
default on fuel pump
default on your gauge

What is your choice ?

Regards
Claude

kossykarl

hi there 2001ode!

no problem with gauge mate as both the pressure gauge and my afr meter are ok, deffo running lean as its running hot and lacking power i have already replaced filter and regulator so the problem has got to be with the pump surely????


cheers karl

alan rainbow

karl ive got a pump you can try if you want

july1

iTrader: (1)

This will be the best thing to do!

kossykarl

thanks !!!!! Alan ,but i`ve bit the bullet and ordered one from GK Ford they will deliver it to work tommorow ( I am parts supervisor for an iveco , ford and seddon atkinson main dealer so get most of my bits at cost) i will let you know how i get on with it but thanks for the offer it was good of you.

by the way where abouts in notts are you iv`e seen your posts on this board all the time and just wondered.

cheeRS Karl.

alan rainbow

no probs mate iam in aspley notts

july1

iTrader: (1)

Another key point to check would be the voltage @ the pump. The poor fuse box is a common problem on escort but as your sierra is getting old such trouble may happen too.
The voltage drop should not be more than 1v.