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Discussion Starter · #1 ·
I have been doing a bit of digging in preparation to more work to the inlet/air issues I had recently & have found a potential issue I may have with my fuel regulator & am seeking your advice/experience.

I popped out my fuel regulator, with a view to changing it & found the following:

This is what my fitted regulator looks like but it has the smaller o-ring missing - (pic found on images, not a pic of mine)

https://shop.grahamgoode.com/fuel-p...ent-cosworth-rs-escort-ybp-ggr923-76481-p.asp

Not knowing the precise way these work I don't know if the missing o-ring is significant, anyone able to tell me if it is an issue or not, as the new one had the small o-ring & so I didn't change it in case this was wrong.
 

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Discussion Starter · #7 ·
I was looking at the set up earlier & trying to work out the way the thing works.

I assume the fuel coming down the fuel line acts on a spring-loaded diaphragm & based on the spring versus vac/pressure from the inlet manifold gives "spring pressure" above "manifold pressure" fuel to the fuel rail for the injectors to use.

After I had worked this out (hopefully correctly) I have come to the same conclusion as the small o-ring would keep the "pump fuel" from mixing with the "regulated fuel" so it seems my theory could be the same as yours.

It needs changing for the one I was intending to fit but stopped short of doing so, as I saw the difference & wondered if I had the right thing.

If that makes sense?
 

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Discussion Starter · #8 ·
Update:

Ok, so after other woes mentioned in other posts on here I have also been paying this issue some more attention.

I bought 2 x "aftermarket" fuel regulators & neither seems to actually do the job of regulating fuel pressure!

I currently have the original fitted with a new 2nd o-ring fitted & that one gives 4.5 bar at idle & that drops with revs!

One of the others simply didn't fit.

Another actually blocked off the outlet to the injectors.

I have had enough of trying sub-standard stuff (see other posts today) that should do what it says on the tin, so my question is.

Do I just need to go to the local stealer & bite the bullet or is there a recommendation out there?
 

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2006 R53
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Update:

Ok, so after other woes mentioned in other posts on here I have also been paying this issue some more attention.

I bought 2 x "aftermarket" fuel regulators & neither seems to actually do the job of regulating fuel pressure!

I currently have the original fitted with a new 2nd o-ring fitted & that one gives 4.5 bar at idle & that drops with revs!

One of the others simply didn't fit.

Another actually blocked off the outlet to the injectors.

I have had enough of trying sub-standard stuff (see other posts today) that should do what it says on the tin, so my question is.

Do I just need to go to the local stealer & bite the bullet or is there a recommendation out there?
I have two stock regulators here if you need but you'd have to swap your O rings over
 

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2005 R53, 2005 R53 lightweight, 2008 R55S, 2012 R58FJCW, 2014 R60SD All4, 1996 Mini Cooper 35SE.
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is it actually affecting your car and the power you have or are you just tinkering for the sake of tinkering? haha
 

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Discussion Starter · #11 ·
Not necessarily causing an issue, I just checked it & noticed it was wrong, so want it right, otherwise I am more in the region of less fuel in the engine at wot, which is never going to be good.
 

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Discussion Starter · #15 ·
I am not measuring it under load and don't REALLY have to, to start with.

The fuel regulator consists of an internal spring behind a diaphragm, which is also assisted/negated by the intake pressure such that the injectors SHOULD always put out 3.5 bar to the fuel injectors.

Therefore at idle with negative inlet pressure there should be a small amount under 3.5 bar at the rail & with the s/c at full chat there should be boost pressure plus 3.5 bar at the fuel rail.

As I am seeing more than 3.5 at idle & a reducing pressure when revving the engine & therefore getting boost, the regulator is therefore goosed.

Having said that I am not saying that the pressure under load isn't important, it is & if that is then reduced with a greater fuel demand then the pump isn't up to the job of supplying enough fuel at the correct pressure, but that is not the problem with the regulator.

Simples!
 

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2006 R53
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Your pressure at idle with the reference line attached should be 3bar. With the line detatched it should be 3.5bar. Unless you cable tie the bypass valve shut then the amount of boost you will generate just by revving the engine will be minimal. The absolute maximum fuel pressure the stock system can generate is 4.5bar, which is equivalent to 3.5bar base pressure plus 1bar of boost (the bypass valve on the filter bucket is 4.5bar)
 

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Discussion Starter · #17 ·
OK, well, I am in complete agreement with you apart from one thing, boost when revving the engine at standstill.

My MAP sensor registers 22.7psi at 6k rpm with 17% pulley & belt.

All of which is completely irrelevant as at idle I am getting 4.5 bar, which then reduces as revs rise, so my regulator isn't doing what it should & has to go.
 

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You are mixing up absolute pressure with gauge pressure. You are seeing 3.5 bar + 1 bar atmospheric pressure, and 22 boost - 14.5 psi atmospheric pressure. This is actually 7.5 psi in gauge terms, or as I said before.... fuck all
 

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Discussion Starter · #19 ·
Sorry mate, I am an instrument technician by trade & I am not mixing up "gauge" with "absolute" pressure.

The gauge I am plugging in reads zero when I plug it in, not 1 bar when I put it on my tyre inflator & gauge (as I did to check it's accuracy) it reads EXACTLY what the others do.

If it were an "absolute" calibrated gauge it would be reading 1 bar when not connected!

My MAP sensor read zero when the engine is not running, so is ALSO not calibrated to read "absolute" pressure.

DON'T DARE TRY TO TEACH ME THAT ONE!

Next!
 
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