Walbro High Volume In-Tank and Inline Fuel Pumps - One of the leading original equipment fuel pump suppliers, Walbro fuel pumps set the industry standard for quality and dependability. Walbro has entered into the performance world with the hottest selling and most frequently used performance pumps on the market.
99.997% of all Walbro Fuel Pumps ship the same day you order !
|Walbro In-Tank Fuel Pumps with Installation kits||Walbro In-Tank Fuel Pumps Only||Walbro Inline Fuel pumps|
|Walbro Tech Info. (FAQ)|
To order Walbro Fuel Pumps go here.
Walbro Fuel Pump and general fuel system information
We are commonly asked "what is the difference between the Walbro pumps? I thought they only had a 190lph and a 255lph pump...?" Well, there are actually quite a few different Walbro pumps that they offer. First, we have the 190lph, the 190lph-HP, the 255lph, and the 255lph-HP. Then we have the "flipped" versions of the Walbro 190lph, the 255lph, and the 255lph-HP (no 190lph-HP). SEE PIC BELOW. These pumps have the inlet rotated 180 degrees from the inlet. The reason is to allow for a greater number of fitments. With these 7 pumps, Walbro can fit numerous vehicle applications. Other than that, each "series" of pumps is the same in terms of fuel flow characteristics.
Walbro Fuel Pump Matrix
|Walbro 190lph||Walbro 190lph-HP||Walbro 255lph||Walbro 255lph-HP|
|GSS278 (flipped)||N/A||GSS315 (flipped)||GSS341 (flipped)|
Another question we are asked is "what Walbro pump do I need and what is that HP about?" That questions is simple but technical at the same time.....to be continued
Regarding the HP question, that is fairly simple. If we take the two 255lph pumps and look at the pressure curves we see that they are very similar until about 60psi. After that point, the standard 255 pump starts to die off whereas the HP keeps going.
To use an example to illustrate pump choice, we will look at a turbocharged Acura application. On these vehicles, the OEM fuel pressure regulator is referred to as a 1:1 regulator. What this means is that for every pound of manifold pressure (boost) there will be a corresponding 1 pound increase in fuel pressure. If the base fuel pressure is set at 40lbs and we introduce 10lbs. of boost, the total fuel system pressure at boost will be 50lbs. That sounds good and will work fine with a standard 255 pump but there is one small problem.
The problem is that we still need more fuel than the 1:1 regulator can effectively deliver. One way would be to add a larger set of fuel injectors and use an aftermarket engine management system to control them. The other, more commonly used method of fuel enrichment is the rising rate fuel pressure regulator or FMU. This device functions in a 4:1 (or more) ratio and will increase the fuel pressure 4 pounds for every 1 pound of boost. If we once again set our base fuel pressure at 40 lbs. and add 10 lbs. of boost we will now see 40 additional pounds of pressure for a total of 80lbs. of fuel rail pressure. This goes beyond the capabilities of the standard 255 pump and mandates the use of the 255HP pump. From this we can see that given two different engines, both with a hypothetical 400hp, the one with the larger pressure requirements will need the HP pump, the one with the smaller requirements will not.
Leading causes of Walbro Fuel Pump Death
Debris, normally in the form of fine silt that can make its way past the 30 micron filter sock. When no filter-sock is used or if it is not installed properly, it is not unheard of to find pieces of sand, string, metal shavings, and rubber bits. This is what kills 99% of all Walbro Fuel pumps.
Water present in tank (corrosion of the pump gears)
Dropping of the pump, can break off the nipple at the very least. Dropping the fuel pump can also knock off the cam ring causing the fuel pump to bind and either decrease flow or completely bind up the fuel pump. Dropping the pump can also break the internal magnets and weaken or destroy the magnetic field cause decreased output or no output.
Operating the fuel pump without fuel; this melts some of the internal gears.
Using the fuel pump in a returnless (pulse width modulated) fuel system. (Late model Mustang, RSX, etc...)