It goes without saying that clouds of black smoke coming out of your car is bad news. But a car is very much like a human body. A lot of the symptoms caused due to one condition overlap with those caused due to other conditions making it impossible to diagnose the exact reason. One of the things that can go wrong and result in black smoke, is a fuel pressure regulator gone bad. However, it is also one of the last things that mechanics usually check because they are extremely durable and the chances of them malfunctioning are rare.
But if you are noticing that your car does not start as easily or the fuel pressure drops immediately the moment you turn the engine off, its telltale signs that you may need to take the engine apart and peep at the fuel pressure regulator.
And if it is indeed the culprit, then it’s time to start looking for a replacement right away.
As always, we recommend to our readers to source the part themselves rather than asking the mechanic to buy it or buying it off a retail outlet. The reason? You can save yourself some Benjamin. That never hurt.
Fuel pressure regulators come in a variety of shapes, sizes, and capacities. There are fuel-injected ones to diesel-powered vehicles and carbureted ones. Certainly not a mean feat if you are new to the purchase.
Here’s a small guide to help you understand how a fuel pressure regulator works and what to look for when buying one.
Things to look for when buying a fuel pressure regulator
The fuel pressure regulator plays a critical function in ensuring that the engine receives enough fuel at the right pressure to work at its optimum. In a typical design, it has a spring that pushes against a diaphragm. The spring is predesigned for the optimum fuel pressure for the vehicle by the manufacturer. So, if the pressure is to be overridden, the fuel pump has to generate both enough pressure and pump enough fuel at one time.
When your car is idle, the built-in vacuum hose inside your fuel pressure regulator forces the diaphragm to put extra pressure on the spring. This reduces the pressure considerably. On the other hand, when you accelerate, this vacuum decreases and the fuel pressure boosts allowing the engine to get the required amount of fuel.
A fuel pressure regulator system has many components that need to be carefully chosen to ensure that you are selecting the right one for your vehicle. Here are some of them.
Inlet fittings: Fuel pressure regulators can have one or multiple inlet regulators. The dual ones are usually a good choice for cars or trucks that have sensors or gauges. It may also be used for cars that have two fuel rails.
Adjustable vs. Fixed-Rate: Do you like to tinker with the fuel pressure regulator to set the pressure manually? People with custom hot rods often do this and if this is one of the criteria, then it is recommended that you look for a fuel pressure regulator that features pressure adjustment screws. For everyone else, a fixed rate fuel pressure regulator works fine.
Vacuum Compensation: Some fuel pressure regulators include the vacuum connections that help maintain the pressure differential between the inlet manifold and the fuel rail.
Aftermarket vs. OEM: The never-ending debate of OEM vs. Aftermarket extends to the fuel pressure regulator as well. As a rule of thumb, OEM is always considered to be better quality if you want to really push your vehicle beyond the limits. However, for casual riders, aftermarket parts work equally well and can be a more cost-effective option. Irrespective of whether you are planning to buy OEM or aftermarket, read your vehicle’s manual, get the exact model number and then check out the parts in the market. Do a comparison, read reviews. There is no reason why you cannot get a good quality aftermarket part.
Internal vs. External Fuel Pressure Regulators: Last but not the least, you may want to select from an external and an internal fuel pressure regulator. The advantage of choosing an external fuel pump regulator is that it does not need to be ported with the fuel line directly. This allows you the convenience to install it just about anywhere near the engine if you have the room for it. Aftermarket parts work best for this and your mechanic can explain to you how this works. Internal ones, on the other hand, are usually an exact replica of the OEM parts.
Our pick of the best fuel pressure regulators
All said and done, here’s our pick of the best fuel pressure regulators in the market currently. To ensure that we cater to our diverse reader base, we have selected both OEM as well as aftermarket parts for this list.
1. Holley Fuel Pressure Regulator
The Holley 12-804 is one of the most popular low fuel pressure regulators that works perfectly for setups that require 1 to 4 PSI. For cars that require 4.5 to 9 PSI, the Holley 12-803 is the right model. The 12-804 is made from durable aluminum and has a satin chrome finish that is extremely resilient to corrosion and abrasive chemicals.
It features 3/8″ NPT in/out ports that are designed for single carburetor setups. But with a little tinkering, this can easily fit a dual carb setup perfectly. The dual ports also allow you to add a fuel port gauge that lets you adjust the pressure.
This is a manually adjustable fuel pressure regulator. So, if you are looking for something that gives you an option to tinker the pressure according to your needs, this will be your right choice. Adjustments are ridiculously easy and all you need is a hex wrench to get it done.
The Holley 12-804 also includes a chrome finish mounting bracket in the package that allows you to install it near the inner wells or near the firewall. At under $30, this is one of the best fuel pressure regulators that you can buy.
2. GENSSI Fuel Pressure Regulator
When you are looking for more power or have a turbo setup that needs a good quality, adjustable fuel pressure regulator, then the Genssi Type S should be on top of your wish list. This is a universally adjustable regulator that has pressure adjustability between 2.0kgf/cm²~8.0kgf/cm² which roughly translates to 114 psi.
It features an oversized diaphragm that will allow you to maintain a consistent pressure even on a boosted setup. With a wide adjustment rate and a flexible installation design, it can be suitable for a variety of engines. Even if you do not have a turbo vehicle and you wish to install this, you can choose to do so by all means.
The Genssi type S FPR is easy to install and configure. It features a 360-degree rotating vacuum arm that allows easy fitting of the vacuum hose and 1/8 NPT ports. Also, pressure adjustments are simplified with a simple dial screw. The mounting bracket ensures that this will fit right where you want it to.
Genssi also supplies a fuel pressure gauge with this that eliminates the need to shop separately for it and also allows precise adjustments. Please be aware that the fuel pressure gauge measures in kg/cm2.
The Genssi is also available in a variety of color coatings for people who wish to customize their setups further. At the price, the Genssi Type S adjustable fuel pressure regulator offers tremendous value. If customer ratings are to go by, it is extremely durable too. Great buy!
3. Aeromotive Fuel Pressure Regulator
If you have a modern Electronic fuel injection engine and are looking for a stable and reliable fuel pressure regulator, then take a look at the Aeromotive 13129. This is one of the newest offerings from Aeromotive in a renewed design and a smaller footprint. Thankfully, all of the features that make Aeromotive regulators so popular have been retained in the 13129.
This is a perfect fuel pressure regulator for smaller engines like the GM LS and Ford Mod Motor as well as for models that have transplanted to EFIs.
Installation is extremely simple as always from Aeromotive. There are two ORB-06 inlet/outlet ports, one return port and one 1/8’’ NPT gauge port. It allows adjustable base pressure from 30-70 psi and on a boosted setup, it increases on a 1:1 ratio.
The Aeromotive 13129 is constructed from the most durable T6 billet aluminum and features a convoluted that allows you to maintain the precise pressure at all times. Other features like a stainless steel mountain bracket allow you to install it easily and a vacuum boost port allows stable pressure.
If you are not looking to pinch pennies and are willing to pay the extra dollar for the reliability, Aeromotive is the way to go. It is 100% designed and manufactured in the USA. Top notch performance!
4. Bosch Fuel Pressure Regulator
For the discerning car owner who’s worried about the reliability of an aftermarket fuel pressure regulator, here’s one from Bosch, who are OEM suppliers to some of the biggest auto manufacturers in the world. This is the Bosch 0280160575 Fuel Pressure Regulator that is designed as per OEM specifications for the Audi, Volkswagen and more.
It is designed for long-term leak-free performance and is housed in a corrosion resistant material. Manufactured in adherence to Bosch’s high standards for quality, it features a good quality premium diaphragm that will allow perfect stable fuel pressure at all times.
The fuel return is equally efficient and precise. Owners of the Volkswagen Passat or the Audi will appreciate that this will fit right out of the box. It is an exact replica, the only difference being the cost which is about 50% less than what a local auto shop will charge you for an OEM.
Works perfectly without any problems whatsoever. This is a 4 bar regulator and is not an adjustable one. At the price, this is a steal. Don’t even think twice.
5. Mr. Gasket Fuel Regulator
Last but not the least, we have everybody’s favorite go-to aftermarkets part manufacturer, Mr. Gasket with the 9710 fuel pressure regulator.
Mr. Gasket 9170 is a fuel adjustable carbureted regulator that is adjustable from 1 to 6 psi. It is designed to fit 5/16 inch and 3/8 inch diameters of the inside fuel lines. All the components and fittings are made from durable brass which ensures leak free performance.
Adjusting the pressure is extremely simple and you can connect a pressure gauge to check if it holds the pressure.
The package includes all necessary fittings including hoses and clamps. As always, Mr. Gasket designs a complete package at a very competitive price. These fuel regulators that are designed for specific applications up to 400 HP are very difficult to find. Even if you do find one at a local auto shop, it will be priced at double of what this is available for.
If you are strapped for cash and looking for an inexpensive replacement fuel regulator that can offer trouble free performance for a while, you have just found it. The budget choice.
Contrary to popular notion, it is not necessary that your fuel pressure regulator cost an arm and a leg. It is completely possible to get a good quality one at much lesser than what your mechanic quoted you. This list of the best fuel pressure regulator contains some of the best ones in the market now that give you great quality at a pocket-friendly price. We hope you can find what you are looking for in this list.