Bosch 3 bar regulator

[R0162]

How reliable are these regulators.. mine is 8 years old, i assume they work with a spring so i am wondering if they can weaken over time like the actuators?
Also what would happen if you were to lose fuel pressure?

[TuxMan]

Chris , are you talking about fuel pressure Regulator ?

[Gadgeroonie]

the bosch ones are good - you can check the feul pressure if you are worried

[951]

R0162 said:

How reliable are these regulators.. mine is 8 years old, i assume they work with a spring so i am wondering if they can weaken over time like the actuators?
Also what would happen if you were to lose fuel pressure?

If you lose pressure you will obviously be right in the st!

However when FPRs fail, due to the nature of the design they tend to let more through rather than less - ie they can't hold as much back as the spring weakens or fails.

Regards

Graham

[R0162]

Hi Simon, yes Fuel pressure regulator..i just wondered if they had a shelf life...in the same way as you dont wait for a timing belt to snap before you change it...

Last year i had it tested while driving and i'm sure the pressure was going round to 3.5 bar when putting my foot down, i never thought much about it at the time as my mechanic simply said pressure was good, but now i have researched it a bit more it seems a bit low, as my boost was 1 bar, the pressure on a rising rate regulator should have been going round to 4 bar, and likewise 2.5 bar on tickover.

I will have to check it again on the road...i suppose when these things go it is a gradual deterioration? i.e.as the spring weakens pressure will drop slowly over time as it starts to let more fuel through?

Edited by R0162 on Friday 23 March 10:11

[951]

But surely, our regulators are supposed to be 1:1 not rising rate, so at 1 bar boost you should see 3.5 bar ?

Edit - I assume by 2.5 at idle you mean with the vac tube disconnected?

Edited by 951 on Friday 23 March 12:00

[R0162]

951 said:

But surely, our regulators are supposed to be 1:1 not rising rate, so at 1 bar boost you should see 3.5 bar ?

Edit - I assume by 2.5 at idle you mean with the vac tube disconnected?

Edited by 951 on Friday 23 March 12:00

No at idle the manifold pressure is 0.5 bar negative, so fuel pressure is 2.5, therefore at 0 bar the fuel pressure is 3 bar and at 1 bar boost it is 4 bar...
I believe 1:1 is the rising rate? ...so for every 1 bar increase on the vacuum line the fuel pressure increases by 1 bar...
I did the same in that i forgot the starting point is -0.5 bar...Yellowshed schooled me on this a while back..

[Blu3R]

Chris, rising rate means greater than 1:1 ie 1:1.5 is common. I don't think our standard regulator is a rising rate version.

[951]

Hi Chris, yes I know about the -0.5bar manifold vacuum - that's why I said I assume you mean with the vac line disconnected to eliminate it

I was simply meaning that "rising rate" indicates a FPR that allows the fuel presure to rise at a faster rate than boost, whereas ours should be 1:1 ie it increases at the same rate.

I should have twigged that was what you actually meant by the 2.5 rather than 3.0 bar though.

[R0162]

I stand corrected...i always thought rising rate meant is rises at the rate specified i.e. 1:1...doh.....but ye i think we are on same page its just me confusing things by using wrong terinology ...