Rochester Monojet Carburetor

The 1MV monojet carburetor is a single down draft unit using a triple ventuir in conjunction with the plain tube nozzle. The main venturi is 1 7/32″ in diameter and the throttle bore is 1 7/16″.
Fuel flow through the main metering system is controlled by a main well air bleed and a fixed orifice jet. A venturi velocity power enrichment system is used to provide good performance during moderate to heavy acceleration and at higher engine speeds.
An exhaust gas recirculation, E.G.R. system controls oxides of nitrogen emissions. The E.G.R. valve is operated by a vacuum signal taken from the carburetor throttle body.
A vacuum supply tube installed in the carburetor throttle body connects by a passage to timed vertical ports located in the bore of the throttle body and float bowl. The ports provide a vacuum signal to the E.G.R. valve in the off idle and part throttle operation of the carburetor.
The E.G.R. valve, mounted on the intake manifold, circulates a metered amount of exhaust gases to the combustion mixtures to lower peak combustion temperatures, thereby reducing oxides of nitrogen during these ranges of engine operation.

The E.G.R. system is not in operation during the engine idle.

A pleated internal paper fuel inlet filter is mounted in the float bowl behind the fuel inlet nut to give maximum filtration of incoming fuel.

The carburetor has an aluminum throttle body, a thick throttle body to bowl insulator gasket, and a internally balanced venting through a vent hole in the air horn which leads into the bore beneath the air cleaner. The float bowl is externally vented under extreme conditions through a pressure relief valve system.

The carburetor part number is stamped on vertical section of float bowl, next to fuel inlet.

An idle stop solenoid is used to control idle. The solenoid is electrically  controlled through the ignition switch. When the ignition switch is tunred off, the solenoid is denergized, allowing the carburetor throttle valve to close further, preventing the engine from running after the ignition switch is turned off. On manual transmission models, the  solenoid also deenergizes when the clutch is disengaged.

Rochester Monojet Identification

Monojet Identification

1980 Monojet 1ME Exploded View & Parts List

1981-85 Monojet 1ME Exploded View & Parts List

1985 & Later Monojet 1MEF Exploded View & Parts List

Float Level Adjustment

Monojet Float Level

Fast Idle Cam Adjustment

Monojet Carburetor

Vacuum Break Adjustment

Monojet Carburetor

Choke Coil Lever Adjustment
Quadrajet Adjustment

Trouble Shooting the Monojet M MV Carburetor

Adjust the Idle Mixture


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What Kind of Fuel Mileage Can We Expect

While fuel efficiency isn’t the only factor when deciding on which car to purchase, it is an incredibly important one. Considering the current prices for gasoline, as well as the country’s tumultuous relationship with many oil-producing nations, fuel efficiency can determine your financial future. Rather than changing your plans on which class of car to purchase, you can instead make sure to look into fuel efficiency when making your car decisions.

  • Fuel-Efficient Hatchbacks
    • The vehicles boast some of the best fuel economy in the industry. Many of these vehicles work in tandem with electric engines in order to minimize the fuel needed to power the vehicle. While many of these vehicles can be expensive on the front end, they can end up saving money, depending on the distance you plan to drive your vehicle. The 2015 BMW i3, for example, boasts a whopping 139 miles per gallon (38mpg on gas engine only). Even if you don’t choose to go with an electric car, you might consider another fuel-efficient hatchback. The Toyota Prius is a more affordable option that still gets up to 44 mpg.
  • Subcompact Cars
    • Not everyone is going to prioritize fuel efficiency. Subcompact cars, like the Honda Fit, might be a reasonable option for people looking to avoid hatchbacks and hybrids. The Fit is calculated at 33 overall miles per gallon. Small doesn’t always mean “efficient.” The Scion xb is a small car with only 23 overall miles per gallon.
  • Compact Cars
    • The Honda Civic and Volkswagon Jetta are both on the higher end of fuel economy in their class. The hybrid versions of these vehicles offer the best mileage, while the regular versions are also quite efficient in their use of fuel.
  • Sporty Cars
    • Just because you are looking for a sporty car doesn’t mean you have to sacrifice on fuel prices. Mini Coopers, while sleep and sporty, also offers reasonable fuel efficiency. Mini Coopers maintain an overall score of 30 miles per gallon; however, some sporty cars fare much worse. The Chevrolet Camaro Convertible, for example, gets only 17 overall miles per gallon, which is almost half of that of the Mini Cooper. This just proves that no matter what type of car you are looking for, you need to look into how much money you will be spending on gasoline.
  • Midsized Cars
    • Midsized cars can be a very responsible decision for people who are looking for practical yet efficient vehicles. One of the best options for midsized cars is the Mazda6 Sport. The Mazda gets up to 32 miles per gallon, with the Nissan Ultima close behind at 31 miles per gallon.
  • Upscale/Luxury Cars
    • Upscale Luxury vehicles doesn’t necessarily mean fuel-inefficient. The Tesla Model S, for example, gets up to 84 miles per gallon in tandem with the electric engine. The Lexus ES, which isn’t an electric or hybrid model, still gets up to an overall 26 miles per gallon. The Chevrolet SS, on the other hand, gets only 17 overall miles per gallon.
  • Small SUVs
    • SUV doesn’t have to be synonymous with gas guzzler. These small SUVs offer comfort and size without entirely sacrificing fuel efficiency. The Subaru Forester, for example, gets up to 28 overall miles per gallon, which rivals some of the more “practical” options.
  • Midsized/Large SUVs
    • The Hyundai Santa Fe, which is on the larger end of SUVs, still gets up to 23 miles per gallon. There are also several hybrid SUV options, such as the Toyota Highlander Hybrid, which gets up to 25 overall miles per gallon. Some larger SUVs; however, prove much less fuel efficient. The Ford Expedition, for example, only gets 14 overall miles per gallon.
  • Minivans
    • While minivans can be incredibly practical, they don’t always offer the best mileage. Even the Honda Odyssey, with some of the best mileage in its class, only  gets up to 21 miles per gallon. The Chrysler Town and Country fares even worse, at 17 miles per gallon.

As vehicles continue to evolve, fuel efficiency keeps getting better and better. Even if you aren’t willing to purchase an electric or hybrid vehicle, there are so many options within each class of car, that it’s important to make sure that you aren’t choosing a car that will end up costing you more money than you intended. Depending on how much you drive, fuel can be incredibly taxing on your financial stability. While you don’t necessarily need to make any sacrifices on the class of car you purchase, you might consider paying special attention to fuel efficiency when looking into potential buys. Not only will you save money, but you will be doing your part to help the environment.

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