What pressure should an adjustable regulator be set.
Discussion
haircutmike said:
Else said:
50psi at tickover, 58psi without vacuum pipe connected
Fuel pressure!I tried turning mine up to about40 yesterday and it started stuttering and didn't want to rev.
The mixture also went down to about 9.5-10!
Hi Blitz.
It seems to run well giving a read out undr load of 11.5-12 on the wideband gauge at 30 psi.
Also idles at about 11ish.
I seem to have a problem with the ECU that you may shed some light on.
Goes well some of the time and then often as you accelerate, it cuts momentarily, the gauge drops down to it's lowest reading, (8) and then accelerates.
When I tried a 5.0 ECU it didn't seem to do it.
Unfortunately, even though I had the 5.0 car at my house for 2-3 weeks, the owner picked it up yesterday and I can't test further!
It seems to run well giving a read out undr load of 11.5-12 on the wideband gauge at 30 psi.
Also idles at about 11ish.
I seem to have a problem with the ECU that you may shed some light on.
Goes well some of the time and then often as you accelerate, it cuts momentarily, the gauge drops down to it's lowest reading, (8) and then accelerates.
When I tried a 5.0 ECU it didn't seem to do it.
Unfortunately, even though I had the 5.0 car at my house for 2-3 weeks, the owner picked it up yesterday and I can't test further!
I know you are running the non cat map, but what else is non standard (Lucas wise)? Fuel pressure may drop to 30 psi (or lower) at idle with the vac pipe connected, but the setting without the vac pipe is the important one, as this represents the full throttle pressure you have to set it for. Other readings cant be taken as accurate as you dont know what the plenum pressure is below atmospheric at any point. Those general AF reading are somewhat rich, and although the RV8 does not complain, its not a good idea.
The target AF ratios are:
Light load, cruise 15.4:1 ( this is the leanest allowable)
Acceleration phase 12.5:1
Maximum power 13:1
Idle 13.5:1
I have rarely seen the light cruise value on the non cat map, it only seems to kick in at quite high engine RPM's.
When you say "it" drops to "8" what does? If its AF ratio you are flooding the engine, hence the power drop. Is the FPR a rising rate one or not? It should not be, as the ECU already provides extra fuel when you need it.
The target AF ratios are:
Light load, cruise 15.4:1 ( this is the leanest allowable)
Acceleration phase 12.5:1
Maximum power 13:1
Idle 13.5:1
I have rarely seen the light cruise value on the non cat map, it only seems to kick in at quite high engine RPM's.
When you say "it" drops to "8" what does? If its AF ratio you are flooding the engine, hence the power drop. Is the FPR a rising rate one or not? It should not be, as the ECU already provides extra fuel when you need it.
I am running a modified 4.3 Lucas jobby last "fiddled " with by Austec Racing.
The fueling on a RR was always good.
Everything else ignition, fueling is boggo.
I have an adjustable pressure regulator fitted.
The figures you have quoted are much leaner then I am achieving.
What is a good base line setting for the fuel pressure?
I assume one disconnects the vacumn hose when adjusting, at what Rpm should I adjust it.
I will then test and note the readings on the gauge.
Thanks for your input so far!
The fueling on a RR was always good.
Everything else ignition, fueling is boggo.
I have an adjustable pressure regulator fitted.
The figures you have quoted are much leaner then I am achieving.
What is a good base line setting for the fuel pressure?
I assume one disconnects the vacumn hose when adjusting, at what Rpm should I adjust it.
I will then test and note the readings on the gauge.
Thanks for your input so far!
blitzracing said:
You only have a few PSI over normal before you get issues with the injectors not opening properly anyway (and thats way below 50 psi) . On the non cat map, it will effect the running over the whole engine range, as the ECU cant compensate when its wrong. The best you can do is set the pressure so the mixture is correct at full load, then try and tweak the lower running range with the CO trim on the AFM.
Mmmmm i better get hold of another gauge, maybe mine is reading a bit high 
. I'm running a Motec ECU with an adjustable fuel pressure regulator and standard injectors at the moment.Andy
I had a very imformative conversation with Blitz last night.
My pressure was way out!
Disconnect vacumn hose to regulator and block off.
Switch on ignition, as the pump primes you will get a reading before it cuts out, set to 36-37 psi then fine adjustments can be made which is another story and I need to go to work in London....NOW!
My pressure was way out!
Disconnect vacumn hose to regulator and block off.
Switch on ignition, as the pump primes you will get a reading before it cuts out, set to 36-37 psi then fine adjustments can be made which is another story and I need to go to work in London....NOW!
I had a fuel pressure regulator, the best value I found was about 38psi iirc. The theory is that the factory regulator won't handle a 5 liter with flowed heads and intake on full throttle and the fuel rail will run out of fuel.
Rob convinced me it wasn't necessary so he took it off, I have to admit I do a lot of full throttle driving and never noticed any problems with the standard regulator.
It did look pretty cool, chrome unit with gauge sitting next to the plenum, I still have it if anyone wants to buy it
Rob convinced me it wasn't necessary so he took it off, I have to admit I do a lot of full throttle driving and never noticed any problems with the standard regulator.
It did look pretty cool, chrome unit with gauge sitting next to the plenum, I still have it if anyone wants to buy it
haircutmike said:
I had a very imformative conversation with Blitz last night.
My pressure was way out!
Disconnect vacumn hose to regulator and block off.
Switch on ignition, as the pump primes you will get a reading before it cuts out, set to 36-37 psi then fine adjustments can be made which is another story and I need to go to work in London....NOW!
Bin the cheap after market regulators ,I went with the Malsappi 1:1 Linea not rising rate .,i took V8 Developments advice....Not been around im in Adeje Tenarefe..Diesel 85p a litre petrol 90p ..My pressure was way out!
Disconnect vacumn hose to regulator and block off.
Switch on ignition, as the pump primes you will get a reading before it cuts out, set to 36-37 psi then fine adjustments can be made which is another story and I need to go to work in London....NOW!
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