Studying for the army’s asvab auto&shop portion of the test. This helps me put what I read into pictures. ❤

My mind was blown at 2:00. Yes, I am apparently an idiot, but at least I'm trying not to remain one :-). This was super helpful and to the point. Thanks!

This was great. Thank you. Much informtive, very help.

Short and informative. Thats how we like it. Great ideer 👍😉

Depends on if your pcm is set for vacuum/boost reference in the injector flow table to wether you connect the vacuum line or not

Got a new subscriber as soon as you mentioned the title. I need this, quick and to the point, How not to be an idiot.

Nice, brilliant technical introduction to differential fuel pressure and how it relates to dynamic engine loads 🙌🏼 This is a fundamental concept and your delivery was spot on for all levels 👌🏻 P.S. Love the engine simulator and gold box being used for your flow bench rig, would have been even better to see what fuel flow meter you were using 😊

does the fuel regulator need hold pressure at prime to 40+psi and suppose to hold at 40+psi ? or is it ok to go to 0psi after prime but no full ignition - is this a cause of a leak down bad regulator not holding pressure before ignition

So the hose to the intake manifold connected to the regulator I’m guessing so that I’m not an idiot is a constant vacuum so that the vacuum decreases as I smash the throttle

solid video really explains a lot. I am building a 1992 Celica with a Turbo charged 5SFE engine, i'm going to be using a Haltech elite 1500 to run it with 550cc injectors, walbro 255lph pump. Should be i looking at an AFPR too or will i be able to program this variable through Elite 1500?

If you don’t have or lose vacuum to the regulator would that let the engine crank and start but die immediately after? My engine will crank and start but dies immediately but I lost vacuum with the line.

Great explanation, your the man

Is the vacuum connection also necessary for carburetor applications?

So what should the PSI read on the FPR for my TBI at idle on my 1995 GMC K-1500 with 5.7 Litre?

very good video my brother ..you would be a excellent instructor...i would definitely sign up for your class..

Nice work, one question, is there fuel pressure regulator for turbo aplication only? or all the same to non and with turbo aplication?

Nice video, question, so I have just got a car, and the vacuum hose from the manifold isn't connected to the fuel regulator, and the that small connection on the fuel regulator leaks small amounts of fuel, it also sits at 50psi all the time. The car runs rich and can't hold a steady idle until it's warm. I assume the regulator is busted as fuel shouldn't come from that side connection and will need replacing, at which point I can connect the manifold vacuum tube and that should remedy in some way the rich running? Am I on the right track? This is my first car that I'm tinkering with so it's a steep learning curve!

Does the same rule apply with a carburetor? Do I run a line from the regulator to the intake? I was curious where that went coming off the regulator

Ok stupid question, I have an ls intake for a 4.8, the intake does not have the fuel pressure regulator nipple on it can I t into the nipple that the pcv valve comes off of?

Does fuel run through the top portion of the regulator? Mine has a pin hole in the top. Debating on hooking it up or getting another

Thank you please show more when it's working on the test bench

Nice sweet explanation.

This excellent video definitely helped my idiot-itis symptoms!

So... Relatively speaking it does keep the fuel pressure constant, as a function of the manifold air pressure variable? Loving these videos so much.

I once saw somebody installing this in a diesel om606 engin what’s the use since you don’t have any vacuum

I have a volkswagen polo 1.4 year 2000 the engine light warns me of code17559 does this include the fuel regulator i have change everything else in that code

Whats a fuelplumb? Haha :) No seriously good video... looking forward to the next one

If u have fuel in the hose between the intake manifold and FPR does that mean FPR is bad

Finally explained ! big thanks

I get F1007 and F1014 codes still searching what they mean. Somebody suggesting it may be crankshaft or timing issue, maybe crankshaft sensor, but I doubt car could be out of timing as it was not opened. Someone suggesting it’s a fuel problem perhaps too much fuel. It’s a Peugeot 207, any idea where to start?

Dumb Question: I only have a carburetor, no ECM or any type of boost. Still connect hose to intake manifold?

Why does some vehicles have a solenoid in between the manifold intake and fuel pressure regulator?

my car will not run at all itll start and idle insanely bad for a few minutes then come outta it some times but something ive noticed is when it does run it misfires and has very poor throttle response pump works fine but there is no gas coming outta the return line so could it be its not getting enough vacuum or its just comepletely locked up or something ive bought a new regulator fingers crossed this is it ive also changed the filter to no avail

Can anyone help the original mercedes e190 w201 is crazy money can I use anything else

Some fuel regulators are in the gas tank like in my ford explorer. Thus it has no vacuum line to adjust pressure. It uses a fuel pressure dampener instead.

Thanks very helpful

How does this differ in a DI car?

This helped. Thank you

Some systems had other ways of adjusting that and the fpr did not have a hose. So dont freak if yours does not. For some issues or to just give the car a bit of zip, one could up the fp a few psi. Fpr were on both electronic systems and mechanical fi systems.

Finally! thanks a lot!

If I have a slightly bigger fuel pump than stock, something like a 255... Would that make my stock fuel injectors leak... And if the answer is yes, could a fuel pressure regulator correct this problem...

Wait, how come in my car the FPR is located passed the fuel injectors? 1991 Honda accord

Is this only for EFI

Im sorry but when you connect the FPR to your engine you shouldnt connect the vaccuum line (yet) because you wouldnt be able to tell the actual fuel pressure coming from the pump if the manifold vaccuum is meddling with the fuel pressure when idling. So first you hook it up, check and set the pressure without the vacuum hose and THEN you connect the hose for a proper working FPR. Right?

So, in boosted applications, would you need higher rated fuel injectors? Or does the fpr compensating fuel pressure completely solve the issue?

Great Job..Ty.

Do you recommend a fuel pressure regulator on every engine? I'm planning to install one on my motorcycle. But I don't see if it would benefit.

Already set my base fuel pressure. Do I need to hook up boost reference vacuum, if I'm N/A.?

can you show it in/on the vehicle instead of the bench mockup?

I need to replace my fuel filter in my Polo. I have two options: one without an integrated pressure regulator (cheaper) and one with. Which one should I buy?

Well if I say a fuel pressure regulator job is to keep a constant pressure difference between the fuel pressure and the intake manifold pressure then it will be correct. Having it set to 50 PSI fuel pressure, and when the intake manifold pressure goes to 20 PSI, the regulator will let the fuel pressure reach 70 PSI ?

Curently working on an NB miata The fuel pressure regulator is situated in the tank, and not connected to MAP It's suposed to regulate to a constant 3 bar The car had trouble starting, took a long time to start, then was running but really low on power... I've changed the pump because I suspected either the fuel regulator or the pump to be bad... The new pump is a high flow pump, not OE one . I was unable to find a fuel regulator (for a decent price that is, cause OEM part is almost worth the price of a decent aftermarket adjustable fuel regulator) The car now runs great, but I find the pump is a bit noisy (maybe because I didn't put panel and insulation back) I wonder if the pressure regulator is fine, or the new pump might just be sending enough pressure to compensate for a bad regulator, and will die soon if I keep runing it like that. My main questioning is, can I delete the OEM regulator and replace it with an aftermarket one, that would rather be in the engine bay, or next to the fuel tank (but not in)? If so should I run it to MAP (car is N/A but might be supercharged later so then obviously)? I don't know how the factory ECU works with the fuel pump but it feels like it's simply regulating pressure/flow by RPM thus increasing voltage output at the alternator and consequently at the pump... If I put a variable fuel regulator, I don't know how it would react...

Well ok. How does it work with a carbonater. Not everyone has fuel ejection.

Would the same apply to a naturally aspirated EFI 2-stroke In a jetski?

Is it the same for a carbureted engine as it is for one with injectors ?

What is not discussed as this does not apply to direct-injected engines. You leave that barb wide open, open to atmosphere that is. The commanded high pressure fuel pump controlled by the ECU will adjust the fuel pressure.

Hello from Argentina! Great video! Just to check if I got it right. FPR is not there to assure constant pressure on the fuel rail but to assure you have a constant dP across the injector (between intake manifold and fuel rail). I assume that's because when you get an injector, the flow spec (let's say 250cc/min) is given at a constant dP (let's say 3 bar) and if for example in the case the throttle is closed you'll get a higher dp and that means higher fuel flow on the same injection time. Please say I'm right up to now. So.. I first want to say that I'm really new on EFI, I'm trying to learn to convert an old carburator car and I know I can really sound like an idiot with my question.. but what I don't understand and I would really appreciate your comments is what about the regulator without the vacum/boost port? is there any way to compensate with tunning? For ex on the same case I comented above (closed throttle) lowering injection time? Thanks in advance!

Do OEM manufactures compensate via ECM instead?

thank you

I thought the FPR should be mounted after the fuel rail, not before it (as you have it).

It provides relative constant pressure.

fuel pressure regulator BEFORE or AFTER the fuel rail?? i thought the injectors need a specific fuel pressure to work properly, therefore the fuel pressure regulator (fpr). Now I was told that you should install the fpr after the fuel rail....that would put as much pressure on the injectors as my fuel pump can do - which in most cases is way too much??

The vacuum line is only on boosted applications that is the boost reference you do not hook that up on a naturally aspirated vehicle.

If your a high HP application this set up will destroy your motor…. FPR after the fuel rails. The fuel pump should be supplying straight to the rails.. then be regulated after

Do all engines require manifold pressure compensation? I have a naturally aspirated, throttle body injected engine and have always run the compensation port on the regulator open to atmosphere. My FP regulator is installed on the return line to the tank, not on the pressure line from the pump. With oxygen sensor in the exhaust controlling AF ratio, how would manifold pressure compensation help me?

Oh !!! this is vocabulary lessons.

What if you dont have an intake manifold?

I still don't understand why the fuel pressure regulator is connected to the intake manifold by the vacuum line... there's a pressure sensor in the intake manifold, couldn't the ecu just read that and tell the fuel pressure regulator what to do? Or is it the case here that the fuel pressure regulator determines the pressure by itself via the vacuum line without any input from the ecu?

Ok good. I needed that. Today I found a teeny tiny vacuum line cracked on my gmc 5.3 that was sucking air. Trying to figure out it’s purpose. I finally got to understanding it to be the fuel pressure regulator vacuum line. So next I wanted to know if it mattered, that’s how I ended up here. Thanks. I will tape it up to repairs the crack for now, and replace it when I find a hose.

I feel not so dumb now. Thanks EFI. Me no dumb dumb no more.

that doesnt work on stock ecu tunes that run in static/closed loop, even with a return line. i drive an srt4 and have the FPR nipple un-plumbed until i get a tune where the fuel trim is adjusted, til then, the mopar ecu handles those parameters just fine for me and theres no need for a boost or vac reference.. the pump is a walbro 255 also, so im not pushing the pump to its limits either, something else to consider..btw, the srt4 guy i took my car to for the custom fuel setup, told me that himself and FWD here in houston has a very highly respected reputation, until you get a CUSTOM TUNE, theres no need to hook up a vac/boost source

NO ONE, NO QUESTION IS DUMB!!!

Thought he was going to show some examples instead of talking about it

I didn’t get it. I thought i knew about fuel, now im scratching my head

If I put 50 pounds of boost to my engine it will blow up🤣🤣🤣

The fuel plump.

Weird though, because on a K20A engine swap it doesn't like having that vacuum connected; throws everything off so we just leave it off.

How come nobody explains where the fuel goes in/out on the regulator?

So just to sound like an idiot... Your video actually told me what a fuel pressure regulator's job is and what it does but not , you know... How it works. Please correct me if im wrong i am learning this stuff as fast as KZfaq can teach me

I dont have a fuel plump

Come on guys this is simple

no pressure

Liked just for aesthetics alone

Lol lol lol lol lol !!!!! Yo, did he jus say “ how not to be a nigga” 0:23 ? Lol lol lol lol !!!!!

Neat clip but fails to address NA applications. Not everything has a supercharger or turbo, what about NA applications? Is vacuum reference still required or not needed? Seems odd to leave NA applications out of the discussion entirely

Shouldn't the title be "Understanding how a Boost reference fuel pressure regulator works". A real explanation of how the regulator works would be talking about the valve and spring that help regulate pressure.

Just make a bloody diagram.

And this only applies to returnless Fuel system in boosted engines

Love the WRONG! Followed by something that isn't true all the time.

well this was a waste of time

This is negative and pretentious