had the car on the rollers today and im being limited to what power i can make due to fuelling

initially thought it could of been an old fuel pump but it was in actual fact a walbro item

changed the fuel filter to which mate a slight bit of difference but not much

so im therefore thinking its the fuel pressure regulator as its probably over 15 years old now so if im going to replace it i might aswell do it with something better!

confused as to what ratio of rising rate i need or if i need it at all and what make to settle for?

any input or if anyone has one kicking about il come and collect it tonight if local!

cheers

 

There's garages across the road from me, don't think you're in one of them though. Change the location in your profile mate.

Don't skimp on an Ebay FPR, Fuelab from Alyn @ AS Performance : 0191 4103770, or from Mark @ Lateral Performance.

 

As above, I've had a Fuelab FPR for 7 years on one of my cars, and it's been faultless (running anything from the standard 3 bar up to 4 bar now).

Don't get a rising rate one, you need a 1:1, but either way Alyn will know what you need so give him a call

 

Ok sweet il perhaps give him a call or probably get a sytec one as it will be good enough for what i need i think!

Was after a good used one but now i know to get a 1:1 one it has narrowed the search down a bit!

What pressure is the standrd one meant to maintain and is does that rise in rate or not?

 

The standard one is 3 bar.

What this means is that it maintains (as long as the pump can supply fuel, the fpr flow rate isn't maxed out etc etc) a fuel pressure which is 3 bar above the manifold pressure, i.e. when on say 1.3bar of boost, the actual fuel pressure will be 4.3 bar. When the manifold is in e.g. 0.6 bar of vacuum (e.g. when cruising along with little throttle, or idling), the fuel pressure will be 2.4 bar.

The standard fuel pressure reg is a 1:1 device, which means that for every x bar pressure difference in the manifold, you'll get x bar pressure diff in the fuel rail. If you had for example a 1:1.5 (rising rate) FPR, then at say 1 bar boost, you'd end up with 4.5 bar of fuel pressure, instead of the 4 bar that a normal FPR would give.

 

So in real terms if im just fitting a new fpr with no mapping i want 1:1

If im fitting one at the time of mapping its irrelevant the rising rate?

Il stick to the 1:1 tbough and set it as per standard in the hope that its more consistent

I might invest in a decent wideband to just to check

Are the fse/sytec ones any good?

 

i am in the same situation with my classic, my injectors are maxed out at 1.3 bar on a TD05, the Fuel lab ones are very good but a little expensive, i have decided to go for the FSE regulator which can be had for around £100 new on ebay with the adaptor that replaces the stock fpr

 

Think im gonna go for fse im currently making a take off for the fuel rail now and a t piece to fit a guage to monitor the stadard pressure to prove the regulator is at fault to fit just after the fuel filter for now

 

Could of course still be the pump not able to keep up. Ive had a walbro fail in that way. Pressure dropping of at the top end

 

Yh i did think that so thats why i have made a guage piece to to prove the pressure thats being maintained in the rail now and il GoPro under the bonnet to see if it fluctuates in anyway

**** but i hate spending money needlessly haha

 

No i agree. But it still wont prove if its pump or regulator. I have a fuel pressure guage in my car. Been having a few issues myself this week. Pressure not being mantained at high boost. Although it did climb to the correct pressure then as the car went futher up the rev range the pressure dropped away. New rcm pump fitted today and problem solved. Previous pump was an hrc340lph and only six months old so its going back

 

Yh but with the gauge i will be able to monitor if the pressure is falling away or being maintained correctly surely???

If the pump cant keep up then id of said the pressure will fall when flat out

Its more than likely though going to be a process of elimination so il try a regulator first which i will probably need in future anyway and isnt a bad investment then if i still cant make the correct afr and the injectors are still at 100% duty cycle flat out even with the pressure upped it will obviously point to the fuel pump not flowing adequately

 

Agreed. If its being mantained then you need an up in pressure or bigger injectors.

 

I cant see it being the pump because the pump seems to sound like it is running strong all the time (car is stripped out so can hear the buzz amongst other things)

Il see what happens...just made my fuel rail take off!

 

well the engine blew friday (2 days after mapping)

blew a big end out after only 3 laps of mallory!

iv got my new engine in and fired up today with a fuel rail take off and also i made a part so i can check the pressure and run the standard regulator until my sytec one comes

whats interesting is though the guage which was a 6 bar one blew up on initial priming so either the guage was fooked or it proves i have no fault at all with the pump!

i wanted to see what the standard fpr was running just on tickover so i can adjust the sytec one to suit until its run in and mapped!

il try guage number 2 tomorrow

what should the fpr be at tickover just to double check...3 bar - vac pressure so roughly 1.8 bar???

 

Yea around 3 bar

 

they vary slightly depending on exact age/model of car but but they show around 3BAR at idel (vac disconnected), approx 2.5BAR vac connected

 

Weber Cosworth FPR mate FSE ones fluctuate too much and are ok for non turbo cars

 

My regulator has a serious fault then

Iv made some parts so i can put the standard regulator where i want with the guage before the regulator so i can see what pressure i have in the rail

I ew the first 6 bar guage up which i thought was odd and iv now fitted a 10 bar guage that is indicating the fuel rail pressure is over 8 bar!!!!

How can this happen?

 

plumbed back to front??

 

Yes lmao just after i wrote it i changed it and sorted it now

Id say there is no problem with the fuel pump though now!

Gotta run it in now

Done 20km no problems lol another 30 and id say yhats one critical point passed! (Did just hg on my old engine and crank went at 50)