Holley 12-804 Chrome Carbureted Fuel Pressure Regulator

Great product from holley, but these do not come with the supplied tap that's suppose to be in box for the 2 machine screws that mount the regulator to the bracket. Somewhat of an inconvenience but that's why it's probably cheaper than other places selling the same part number. There's always a catch with bargains

This is a great fuel pressure regulator when you need between 1 and 4 pounds of fuel pressure.

Purchased the regulator from Baxter, unit arrived in 4 days..However the part number on the box was 12-804 which should be a 1-4 psi regulator BUT the Part number etched on the unit was 12-804 4.5-9 psi which doesnt exist. The 4.5-9 part number should be 12-803.I contacted the supplier and he offered to resolve the issue.However I also contacted the Holley support number and was informed that some regulators were mislabeled. The issue is with the labeling and the internal spring. The 12-804 1-4 psi unit should have a red colored spring. The 12-803 4.5-9 psi spring is plain, (just the gold colored plating) the spring is accessible and replacable by removing the 4 screws holding the unit together. Holley offered to send me a repair kit with both springs at no charge. When you purchase one of these, it is probably advisable to open the unit and check to see if you have the correct spring. If your unit is mislabeled, contact Holley for a replacement spring.

Great regulator for a non-stock application. My Edelbrock 650 AVS needed less fuel than the stock mechanics fuel pump was pushing.

Pictures are on the way

I installed this on my Onan 7000 generator as part of a project to resolve vapor lock issues in hot weather and high altitudes. The project involved installing a 250LPH electric fuel pump on a relay system and then T off to a bypass line and a fuel pressure regulator on the fuel line going to the generator. My bypass line has a shut-off valve that I can use to manually adjust the pressure, but when air bubbles develop within the input fuel line, this valve requires adjustment to maintain the fuel pressure. My plan was to install a fuel pressure regulator on the line going to the generator so that the bypass valve needs less fine tuning to maintain the same pressure in all temperatures. Unfortunately, this fuel pressure regulator does not even come close to regulating the pressure and keeping the pressure down. I feel lucky that this did not damage my generator because at one point I saw 30lbs of pressure while trying to start the generator. This was the second pressure regulator that I have tried. The first regulator was made by Mr. Gasket but had the opposite problem where no matter how high I adjusted the pressure in, I could still not get any fuel pressure to the generator in hot weather. When the air temperatures would get high, the pressure would start dropping until the fuel pressure gauge would read zero. The generator would continue running for a while but would eventually shut down completely. In the hottest temperatures the generator would restart after a few minutes but would shut down again within 10 minutes or less.

I had a chrome dial regulator, which leaked gas everywhere but luckily didn't actually burn down my ride. Then I got this good one, to try to get 1.5 PSI to the Kadrons. At first it seemed fine, set it to 1.5 PSI and away we go. Got a gauge on the FPR to monitor, and at first it was great. Later, every time I checked it, I'd get a different pressure...[Edit to update: This FPR didn't fail after all! What happened was that I was using a liquid filled pressure gauge, mounted in the engine compartment. It got hot, and gave a wrong reading. Got a regular non-liquid filled gauge, and it's great. Regulator was fine all along.]

Works and does the job. I do wish there were some stamped values on the adjustment screw like other models I have seen. Otherwise it's good.

Worked great for my Fuel injection to Carb conversion on my Volkswagen Vanagon

I ordered the 12-804 regulator online because I couldn't find one locally, this is for an engine on a piece of equipment that I make my living with. The regulator that was shipped to me has an internal spring from a different model of regulator, the spring should be red. As you can see in the photo it's gold, (the same colour as what's in the model 12-803)I called Holley directly and customer service is acting like they're unaware of the issue, even though I've read threads online going as far back as 2018 mentioning this.Now my equipment sits idle while I wait for a response from the vendor. It's not the vendor's fault, these things should have been recalled, or the vendors made aware of the issue so that they could be inspected before they're sold.

Regulator Box showed signs of being opened and clumsily closed and the advertised Rubber Gasket or Gaskets that were mentioned in the instructions were missing.The unit however is working fine but am curious about the missing gaskets and how important they are?

Worked well out of the box. It needed a bit of adjusting for my purpose, but other than that, it performed perfectly. Will buy again if I need another one for a different project. Shipping was fairly fast.

This is a good quality regulator and works great on my V8 Flathead Carb . bringing the fuel pressure down to 2 1/2 psi . Fast delivery and because of where I live off the beaten path , a potential delivery problem was resolved for me in a quick and pleasant manner by Josh of JBs Power Centre . I will shop here again .John B