Yes, we know it's still Monday in some parts of the world, but it's already Tuesday in the Antipodean time zone - so it's time for another Tech Tuesday! Today we're talking Fuel Pressure Regulators - what they are, how they work, and why you should have one! Enjoy:) Got a subject you'd like us to cover? Let us know in the comments section!

@stykytte

5 жыл бұрын

It's well into Tuesday in merry old England, and as you know we have a secret government laboratory under Greenwich known only as "Meridian" where the queens finest corgis run on treadmills to generate the time space continuum, so I think you're good.

@haltech

5 жыл бұрын

Being a part of the Empire we're fully onboard with whatever's going on under Greenwich:)

@boosts14

5 жыл бұрын

Why does my twin intank pump module have a fpr built into it when I have a fpr on the rail?

@nebulae1992

5 жыл бұрын

@Haltech i mentioned a question about this topic a while ago as it is an issue about my build. my car im putting a turbo on has a dead head fuel rail, without a return line. the FPR is in the tank. do i need to install a return line and put a boost controlled FPR in? ill be using an elite 2500 piggy backing.

@sparky173j

5 жыл бұрын

​@@nebulae1992 Yes, the ECU can handle that configuration - as long as the pump can keep up and the injectors can flow enough fuel when you're at maximum manifold pressure. Many NA vehicles are designed for ~300kPa fuel pressure, so you may need to increase the pressure and get a better pump when you boost it. Watch your injector duty cycle when running to ensure that things are keeping up. If it gets above 90%, your system isn't keeping up well enough. It's important to leave some head-room in case you drive in different conditions from when the car was tuned. e.g. on a colder day air is denser, so the engine consumes more air, so you need more fuel. Ensure that the settings are correct. In the F4 page, ensure that the Engine : Fuel : Fuel Pressure Input Type is set to Constant for this configuration. And that the Base Fuel Pressure is the pressure you see in the fuel rail. If you've got a fuel pressure sensor wired in and enabled, it'll be able to respond properly if your fuel pump can't supply enough pressure. Map the Injector Flow Rate table to the Injector Pressure Differential channel. (ECU Navigator : Injection System : Stage X : Flow. Press F3 to bring up table edit, enable the axis and set the channel to Injector Pressure Differential). Pick a bunch of injector pressure differences that you're likely to see, and use the equation below. For most injectors in their normal operating range, the flow is proportional to the square root of the pressure. flow_at_pressure_x = flow_at_base_pressure * square_root(pressure_x / base_pressure). e.g. if an injector flows 1000cc at 300kPa, then at 200kPa it will flow 1000cc * square_root(200 kPa / 300 kPa) ~= 816cc. Ideally you would map your Injector Dead Time across the pressure difference as well, but most people skip it, as the difference is pretty small and it can be tuned around pretty easily.

Not having much experience with boosted engines that really helps me understand how important the fuel system is.

@haltech

5 жыл бұрын

You're welcome:)

I watched a number of FPR vids tonight, yours is by far the best one I've watch. Kodos!

What a well presented video. I cannot help but think, if this guy was one of my teachers when I was back at school/uni, I would have understood so much more!

Just bought a car with a 2JZ and was wondering why there was a boost hose running from the intake manifold to the FPR and this explained it excellently! Thanks :)

Fantastic video. Thank you for your time making this.

Excellent content and concise,Thank-you

Great job 🙌

Well explained, thank you!

awesome video thanks mate

Thank you very much for this video! Best video found so far about fuel pressure regulator 💪

@haltech

4 жыл бұрын

You're welcome :)

Awesome work scotty!

@haltech

5 жыл бұрын

Thanks:)

this is very helpful compared to other vids

Thanks Scotty! Have had a crappy Friday but watching Tech Tuesday always makes me feel good!

Great vid guys

@haltech

5 жыл бұрын

Thanks:)

Fantastic explanation Sir.............i think that this is the problem with my V6.............. subscribed !

Could you expand on this topic please. How does a surge tank come into this. When does the injector open with direct injection, at cylinder top or bottom? If it opens during compression then this would effect fuel pressure requirements? Love your work!

Nice...

I am installing a 6.0 LS N/A engine and my plan is to use a corvette style Fuel Filter/Regulator system with just one fuel line fueling the injectors. You reckon the factory regulator will be efficient enough? Is an Adjustable Fuel regulator more desired for boosted engines?

I vlcke din this as the title intrigued me while I was researching something else lol but I'm glad I ended up here

Interesting, if i still had a stock FPR boosting 10 psi can the tuner add more duty cycle on the injectors when u go into boost to compensate the rail pressure loss ? I've also read that some factory cars already have 1:1 rising rate reg.

Thank you!

Funny I was just talking with my brother about his baja truck on display at Haltech, KY & also talking about my FPR w/ boost reference port & trying to decide if I needed a 3 or 4 port boost controller. I have an electronic fuel pressure sensor connected to the FPR, so maybe that negates any need to hookup boost reference on my FPR?

Just added one to my V-Twin Ultralight engine as the pressure setting in the existing return was set too low, when set at correct 3 bar or 42 psi the difference is unbelievable! @PY84

wow boost even affects the injectors. makes sense tho since its all vacuumed tight..

I know this would be a tall order, but could you guys maybe do a video completing a base map, whilst showing the screen to detail it. I think that would be really educational and interesting to see all the information you guys pour out put into practice. Love this series. Thanks!!

@haltech

5 жыл бұрын

We have something similar in the pipeline:)

@g_wizard9866

5 жыл бұрын

@@haltech Marvellous Effort that!!!!

I think I need a new FPR? This is very informative. I bought a car, turned up not able to start. Replaced fuel pump and is now running but feels like fuel cutting when on boost. I replaced fuel filter but still feels sluggish. Checked and cleaned intake and intake sensor. No luck :/ I think FPR is my next step

Smart,

Hi there! What if my fuel rail does not have an exit side, where should I put my fuel pressure regulator? Also the original fuel system has return line to the tank. Thanks!

i have a bypass12-887 i have a vacumm port outlet on it do that line have to be hook up

Working with itb’s? Same setup just ignoring boost but how would you measure pressure

I have a stroked SR20 making 500kw atw & when I come off throttle the engine seems to miss I have a basic understanding that nothing is really firing at this point, could this “miss” be due to only having a 800hp fpr & it is struggling to let the excess out of the system?

I have an 05 GMC Sierra with bolt ons Cam, Headers, Intake, tune and a walbro 450 im still running on my stock injectors which they max out around 25psi... My fuel pump runs from 35-87 psi acording to the specs i saw online... My engine feels like it missfires but my coils, spark plugs, and spark plug cables are new, and it started doing that ever since i installed the walbro 450 fuel pump...So my question is, can it be that the fuel pump is sending to much pressure to my injectors??

makes sense! Thanks, never really thought about it before but is pretty important. lol

Hi! I have a question. If I increase the fuel pressure, the ecu can reduce the injectors opening time to regulate AFR?

for NA standard engine better instal fuel pressure regulator also? for constant flow each injector?

Does any of this matter if my car has a returnless fuel system, running a 96 dodge stratus 2.5 v6 in a demo derby, and it has no return line from the fuel rail just a inlet, tried running a 7 psi fuel from a carb set up in there and it did not work, so I am buying a 45 psi pump but was told I should run a regulator, but it’s a derby car so idk if I should or not

so it means it helps give more fuel for better performance right? so consumption also get bigger then

So then, on a NA motor, a manifold reference isn't necessary? Or is there some benefit?

The manifold pressure affect the injectors efficiency?? Lets say I run 50 psi of boost with 39 psi fuel pressure the boost can reverse the fuel injector?

Hello silly question but what would I set the pressure on my factory running non turbo 4 cylinder engine

hows it work with a dead head system?

Sir FPR is it the problem if one outlet from the commonrail has no fuel...

can I install the fuel pressure reg. in the diesel engine?

What about a carb set up? Larry

guys my car makes this hissing sound when starting up and i dont know where its from it doesnt always happen and when i press the gas it stops and lets out the pressure. what can this be? citroen ds3 2010 1.6thp tuned from 155>200hp i have a blow off valve, oil catch can and a different air intake

How do you calculate the boost pressure pushing back at the tip of the injector?? It was 10 psi in your example. Is it your max boost running on ur turbo setup?? Great videos!

@silentbravo

2 жыл бұрын

You probably don't have to calculate anything, the idea of these regulators is that they do it for you. You plumb an air line from your intake, after your turbo, and plug it into your fuel pressure regulator. Your turbo will make different boost all the time and it will push that psi into the FPR which will automatically compensate for it.

I didn't understand anything in the video :( can someone tell me if I should buy a fuel filter with an integrated pressure regulator or one without?

What about dead head set ups? Do they run a long manifold reference line, or is there another way to do it?

@ReubenHorner

5 жыл бұрын

They have a static fuel pressure. The ECU needs to do a bit more work as the deadtime of the injectors changes as the pressure across the injector changes and this happens all the time as your throttle changes. They are not that good in turbo cars as it makes for extra short duty cycle at idle (meaning deadtimes need to be right) or on the other side of life, when in boost you have less flow rate compared to a map referenced fpr.

Can a 255 fuel pump cause stock injectors to leak and cause a misfire... And if the answer is yes, it could, then could a fuel pressure regulator correct this problem...

What about fuel dampers?

What about Direct Injection fuel pressure? I own a Mazda 6 MPS (Mazdaspeed 6) and they are known for weak stock fuel pump (100bar max fuel rail pressure on stock engine). WOT on high gears will cause zoom zoom boom very fast and it's a PITA to drive on Autobahn and jump from 6 to 4 or 5 every time you want to floor it, just because the ECU and fueling is so bad designed on the 2.3MZR DISI Turbo engine. Is there any alternative to changing the internals of the HPFP to mend this "by default" problem or should I go for the 10mm piston and 150+ bar ? PS: The HPFP is the same like on the Golf 6/7 GTI and R from what i've heard, it's just the internals that are undersized .

@eEnzo0

5 жыл бұрын

@@1magnit, Thank you captain Obvious, that piston that I was talking about is from High Pressure Fuel Pump, the mechanical one running at 100 bar on the fuel rail. Read the God damn post before writing something stupid. I was asking for a quick fix or a workaround, and no, it doesn't inject a fixed amount of fuel, it injects the fuel very precise with different quantity every time, you can see that watching the STFT and LTFT in the ecu.

How do I "map my injector flow rate against my diff. fuel pressure?"

Let's say if my factory fpr has a vacuum reference and I've put a turbo on my car and put a higher flowing fuel pump, would it still operate as you've described ? Or would I need an adjustable fpr?

@haltech

5 жыл бұрын

If you're upgrading your fuel system - ie fuel pump and injectors we would recommend upgrading your fuel pressure reg as well.

@naiahhaian

5 жыл бұрын

@@haltech Thanks for the reply! Much appreciated 🙂

Also one thing I’ve leant is that not all fuel regs are created equally try find one that will hold fuel pressure when the engine is switched off as this will make restart the engine a lot easier

@haltech

5 жыл бұрын

^^ very true.

@justincanino8521

5 жыл бұрын

@@1magnit - I've found the GBF fuel regs state they will hold rail pressure when the engine is off unlike the current one i have that leaks down and doesn't hold pressure

Thoughts on returnless fuel systems?

@endurofan9854

3 жыл бұрын

been thingking the same... cuz the toyota avanza has no fuel return system and the regulator is a pretty simple valve(a one way valve)

Possibly a dumb question, but since boost pressure constantly changes, does that mean that fuel pressure is constantly changing along with it, or does the ECU know of the current pressure / flow rate and adjust accordingly?

@Rycoda

5 жыл бұрын

i was wondering the same thing

@cdcoulson

4 жыл бұрын

Not a dumb question, and I don't work for Haltech, but you're semi-right on both accounts. The function of a boost/vacuum-referenced regulator, as mentioned in the video, is to maintain a constant flow rate from the injector-- what this means is that your fuel line pressure will adjust as vacuum/boost comes into the equation, but only in such a way that the fuel pressure differential is maintained. So, for example, your base fuel pressure is set at 45psi with the reference line disconnected. Your injector flow rate at 45psi is 1,000cc/min. When you connect the reference line and allow the car to idle, the regulator will be exposed to the vacuum generated by your reference source-- this means that the fuel line pressure will drop according to the vacuum seen at the regulator. Just to follow the example, let's say manifold vacuum is - 10psi. Your fuel line pressure would then drop by 10psi to 35psi, but with the -10psi acting to "pull" fuel from the injector, the injector would still maintain the same flow rate (1,000cc/min) seen at 45psi of line pressure with the reference line disconnected and no vacuum/boost in the manifold. Conversely, in boost, the injector has to overcome manifold pressure in order to inject fuel, so, as detailed in the video, 10psi of manifold pressure would cause a 10psi increase in your fuel line pressure (from 45psi to 55psi), however, having to overcome the 10psi of manifold pressure means that the injector is still maintaining its flow rate at 45psi (again, 1,000cc/min). Depending on how your ECU is calibrated (Haltech's recommendation is to map fuel flow rate by injector pressure differential), the ECU will constantly recalculate your engine's fuel requirements using the injector pressure differential, the values in the injector flow rate table, the target lambda for that load cell, and the value entered into your VE table (subject to further manipulation by compensation or correction tables [post-start enrichment or ethanol content, for example]). Anyway, I'm still learning, too, but fairly certain this information is accurate.

I wonder how much fuel pressure BMW used to use in their old F1 turbo engines and what method they used to control it back in the day. They were only 1.5 litre V6s, but...with 80 psi or so of boost, and something like 1300 hp.

@wobblysauce

5 жыл бұрын

Quite high, diesel is higher again.

@alexstromberg7696

5 жыл бұрын

@@wobblysauce modern common rail diesel engines have fuel pressures up to 3000 bar. You can't compare the two, most gas cars use pressures around 3 bar.

@wobblysauce

5 жыл бұрын

@@alexstromberg7696 Well, you can... it does show differences.

soooo can we sort of tune air/fuel ratio with different FPR ? my car dosent have a programable/tunable ecu , feels like its runing too rich

@sity909

5 жыл бұрын

just get a different car

@fjsgte678

3 жыл бұрын

The most you can do on ur set up slightly increase your fuel pressure with an aftermarket adjustable fuel pressure regulator to get more flow out of ur injectors at their given duty cycle across your fuel tables. Basically this would be used if ur running slightly lean and want a bit more fuel(via more flow as per the increase to the fuel pressure) going into ur cylinders while not increasing duty cycles %, since ur don’t have an aftermarket ecu to increase fuel. This would be ur little cheap bump In fuel to save potential detonation from running too lean.

The 1 dislike is probably from some Kyle not using a boost-referencing regulator and putting a fist-sized hole in his piston.

@haltech

5 жыл бұрын

LOL...

I understand the theory but I've been told over and over that a regular old top hat, diaphragm vacuum reference non adjustable fuel pressure regulator is fully adequate. Why should i switch, is there really that much more control to be had?

@gammalight1312

5 жыл бұрын

@@1magnit oh, so the main benefit is to reduce flow restriction and of course enable pressure adjustment. That make sense now, thanks!

If you have a single fuel line to the engine with the pump and regulator at the tank how do you adjust for boost, a long hose from the manifold to the back of the car ?

@alexstromberg7696

5 жыл бұрын

The regulator is often in the engine bay, or even directly mounted to the fuel rail

@jrobpat0154

5 жыл бұрын

@@alexstromberg7696 yes but I am talking about modern setups with no return line to the tank, I'm assuming that all regulators have a return line for excess fuel

@d1zguy864

2 жыл бұрын

@@jrobpat0154 ECU controls fuel pressure, guess you just tune it for more

Does increasing the fuel pressure change the afr?

@haltech

3 жыл бұрын

Increasing fuel pressure will change the flow rate of the injectors. If this is not properly compensated for in the ECU programming, the AFR will be enriched as a result.

@DimZin

3 жыл бұрын

@@haltech For example in a stock ecu which is not programmable it will make it richer

Do I need this in my BMW N54 engine?

@sity909

5 жыл бұрын

yes

I don't have a return line

The problem with the definition of a super car is that isn't specific enough. There now needs to be a horsepower minimum and maybe a speed cabability minumum. Beause there are Mini-Vans that can go fast depending on who you ask. And yes, 75 is fast to someone who never drives faster than the speed limit. For Horses ?500? ?550? Hyper cars: 900 minimum? These are suggestions. Please start a conversation on this And the possibiity of a special license for high-end cars as well.

The more you know

So what would increasing the fuel pressure to 65psi on a 40 psi system with 24 lb injectors do?

@haltech

3 жыл бұрын

Provided that 24lb/hr flow rate was rated at 40psi, It would increase the flow rate to 30.6lb/hr. But don't take our word for it, use a calculator!

@19jody72

3 жыл бұрын

@@haltech I dont know the math or science to it..I do appreciate your input

@haltech

3 жыл бұрын

@@19jody72 No problems mate. You're talking to a marketing guy. I don't know the science or math either. I used a calculator I found on Google! I bet Scotty could have done it in his head though. LOL

@19jody72

3 жыл бұрын

@@haltech lol..I appreciate your input though

@2:50 you jam 50psi into the engine. Why 50psi and how? There are some gaps in the process that do not make the video flow logically.

Can a bad fuel pressure regulator make a car not to start

My fuel pressure drops to zero after pump is turned off

Never touched on failure of fuel pressure regulator valve. People watching these videos are generally people who have a specific problem that they're trying to solve and want to know what the signs, signals, symptoms are of a fuel pressure regulator that is failing or has failed are. No mention here.

Why my car runs better with facum line off?

Its funny how the english speaking countries just use metric and imperial interchangeable. 1050cc @45psi. haha, I am 5ft 30cm.

Moist