Fuel Pressure Regulators - What do they do and how do they work? Today we find out on Go Fast Brett! This series is proudly brought to you by Mighty Car Mods and GFB www.gfb.com.au www.mightycarmods.com
I think I know, and then you teach me more and then describe what I thought I knew even better, to where I completely understand it.. Absolutely love this series, great stuff.. PS I just got my Chopped key chain and it looks great attached to the keys of the FRS I just bought (finally! 😃), Cheers!
Excellent presentation - I had to explain the same thing to a friend who's needle and seats wouldn't hold back the pressure of his new pump; tiny NA engines do not need heaps of fuel pressure.. eventually, he ended up switching back to a mechanical pump, but kept the regulator. Go figure.
Hi Brett, In the event of rising fuel pressure beyond what the FPR can bleed off would the ecu not just reduce the duty cycle of the pump? Or is this not an optimum solution due to the time it takes for the pump to change speeds?
I've a stage 2 on my 1.8T,car feels good on boost with a 3 bar regulator but I was told to upgrade to a 4 Bar which I've bought but yet to install,any advice please..
Hi, help if possible. I believe I need a fuel pressure regulator. I installed a fuel tank/cell + pump etc in our rally project. First pump went pretty quick, stopped pumping. After getting advice I learned it's a returnless system. Pump was flowing too high without releasing unwanted pressure. Is any inline pump ok but just needs the correct pressure via regulatory value? Car worked 100% with original tank/pump so I know I have caused this issue. Can you help? It's an efi dohc engine. M15a ignis sport
Hey brett, is this unit capable of adding different amounts of fuel pressure with increased boost? Or does it only add 1psi of fuel for each addition psi in the manifold?
MCM TV2, if my fuel pump is bigger than the stock and I'm running stock injectors... Can this combo create a p0300-code (misfire) to show... And if yes, can I use a fuel pressure regulator to correct this issue (p0300-code)...
Very good explanation but you didn't mention one key aspect. Your FPR holds system pressure AFTER the fuel pump has finished priming to start or has been shut down after running. The hardest thing to tune with an aftermarket management system is the fuel pulse and cranking enrichments with a cold engine if the fuel rail pressure isn't maintained or held consistent after priming. A slow fuel system pressure bleed down is ok ie 5 minutes but when system pressure drops in a matter of seconds, the only way to avoid the problem is to crank the engine to start whilst the pump is priming...and this isn't always feasible or desired. It would be good if you could create to a video of this to show your future customers looking for an acceptable replacement regulator that is similar in characteristics to the OEM regs. After using a Malpassi and TurboSmart FPR's, it's this feature that is by far the most important and made my decision to buy your FPR the logical choice. Thanks.
dumb me gonna ask dumb question: my gf drives an astra... the thing always drives a bit TO lean... it's a uber simple 1.6 8V and have been wondering if a fuel pressure regulator could possibly fix this? or will the ecu just screw me over on this? (yes she has a new lambda)
I have something similar question, the engine i got swapped in had a returnt line and the pressure regulator after the rail, but my stock system have the valve itself on the pump station in gas tank (with no return line). I blocked the outlet socket on rail, screwed in the damper from my stock system before rail and now i dont know how engine feels about it...
and I have in the past... but after hearing MCM talk about why they did (semi return setup... as they called it) on super gramps. I'd like to hear more about it.
Not true, although the majority of cars have the regulator after the rail, some have regulators that t off before the rail to maintain consistent pressure.
Question: 75hp N/A with unknown fuel pressure (in between 1-3-5bar). Will the regulator (if set correctly) increase horsepower significantly enough to justify the cost?
All increasing the fuel pressure does is make your fuel injectors flow a little bit more fuel. Unless you done a bunch of air flow mods its just going to make your car run too rich.
I'm looking for a dirty cheap upgrade, that would bump up the power, but neither ruin the budget or fuel economy. I know, I know, Power = Fuel, More power = More fuel. But since its just (DA)SOHC with 8v, I'm not expecting high gains. ECU is useless without other mods such as flowed head, intake mods, mild camshaft, exhaust etc. It's VW AEE engine, if you desire to be exact.
Like a said before chaining the fuel pressure is just going to make your car use more fuel and run like crap because its running too rich. Just save your money and buy mods that will help the engine breath better.
The only real thing I'm looking for is economy... Somehow, after 13 years, the little xB is only getting 24mpg... meh... I had speculated a few years ago once I started noticing I'm missing half a dozen mpg that upgrading the entire fuel system would help with economy but the money never came.
Really interested in fuel systems again since one of my '66 Fords needs an tank mat (sucks air in turns), electric pump, block off plate, and a regulator. The carb is now too big for the stock pump
Dinklemin Some newer cars will modulate power to the pump to slow it down, but I think they still have a regulator in the tank. I would expect slowing the pump enough to fully control pressure at idle or low load would cause a lean condition if you hit the throttle as the pump would have to speed up and push all the fuel in the line to react.
Not that I'm aware of. With my Focus that I installed a turbo on, I'm pretty sure my tuner just had to work around that limitation of a returnless fuel system. But I'm not running a huge amount of psi or power, so it probably wasn't a huge deal anyway.
same thing mate I have a turbo'd swift with a returnless system has a gss340 walbro pump fitted I think an external surge setup with a custom rail and return would be the only solution
imactownkkid Usually the best solution is to go aftermarket and build your own fuel system. But, if you're not pushing a lot of boost you can compensate with tuning. You'll basically just have to increase the duty cycle of the injectors to make up for the drop in effective fuel pressure. You'll run out of injector quickly this way so may have to get bigger ones. There are also piggyback fuel pump systems that can kick in with boost to get the extra pressure and flow needed. But, they're usually more of a bandaid than a long term solution.
NBSV1 injectors are upgraded to 550cc unsure what duty they're running at afr's stay steady across the rev range at peak rpm it leans slightly hoping to turn the boost up a bit don't want it leaning earlier will have to check out a custom intank setup or external surge that should sort it, hopefully ✌
Dan Borgschulze It depends on if it's a blow through carb or a standard carb in a box. The blow through carb has ports that will reference the boost and put pressure in the fuel bowls as well as some special valving to work with the boost. A carb in a box is usually standard since the box is pressurized it will apply pressure to everything so the carb doesn't need much special, but you'll need to have a regulator like in the video since the fuel going in will have to push against the boost.
Morgan Reed The returnless systems still have a regulator. It's just usually built into the fuel pump assembly. You can sometimes remove the factory regulator and install an aftermarket one if needed.
Diesels run at stupid-high pressures compared to gas, so the injectors need to be bigger. IIRC they run at like 1500psi, but gas engines run around 60psi
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