Grand Wagoneer Carburetor Adjustment – How To

You may want to adjust the carburetor on your Grand Wagoneer but are not too sure how to go about it. We have done the research for you, and here is what we found.

The following are step-by-step guides for adjusting the carburetor on your Grand Wagoneer:

  • Remove the air filter
  • Locate the adjustment screws
  • Check if the engine is rich or lean
  • Tune the carburetor
  • Adjust the idle mixture screw
  • Reinstall the air filter

You don't necessarily need the help of a professional to adjust a carburetor. Keep reading to get detailed information on how to adjust the carburetor on your Grand Wagoneer.

Jeep Grand Wagoneer showcased at the LA Auto Show

How To Adjust A Grand Wagoneer Carburetor

Jeep Grand Wagoneer display at a Chrysler dealership, Grand Wagoneer Carburetor Adjustment - How To

Here are steps to follow if you want to adjust your Grand Wagoneer carburetor:

Step 1: Remove The Air Filter

Open the hood of your Grand Wagoneer, and look for the air filter underneath the hood. You should find it in a black-colored cold air box located at the front of the engine.

In vehicles equipped with carburetors, the top of the vehicle features a spherical air cleaner that is highly noticeable. When the filter is removed, you can then gain access to the carburetor.

You probably won't require any special tool to remove the air filter. If you do, it would be a screwdriver or a wrench. Remove the filter housing's clasp to expose the air filter.

To ensure that your engine receives clean air, you might need to replace the air filter if it is old and dusty.

Step 2: Locate The Adjustment Screws

A common carburetor for a Grand Wagoneer will feature screws that allow the driver to modify and adjust the amount of air or gasoline that is allowed into the engine.

To make adjustments to the carburetor, you need to find these adjustment screws. The screws are typically golden and have a flat head. This indicates that they can be quickly adjusted to the desired level of tightness or looseness with a flathead screwdriver.

In addition, a choke valve should be located on the air inlet of Grand Wagoneer carburetors. When starting a cold engine, it controls the flow of air through the engine. 

Click here to see this flathead screwdriver on Amazon.

Step 3: Check If The Engine Is Rich Or Lean

Turn on the engine and pay attention to how it behaves as it approaches the temperature at which it performs. You should determine whether it is operating on a rich or lean basis.

When an engine operates in a lean condition, it consumes an excessive amount of air compared to fuel, resulting in a lack of power, slow acceleration, and the engine not starting. On the other hand, an engine that runs rich burns more fuel than air.

Step 4: Tune The Carburetor

Mechanic man adjust the carburetor of the car at repair service station

After determining if the carburetor on your Grand Wagoneer is operating on a lean or rich mixture, you can then make adjustments to the carburetor.

When you turn the adjustment screws on your carburetor clockwise, you can increase the amount of air or fuel that is allowed into the engine. Similarly, if you loosen them, the amount of air or fuel given to the engine will decrease.

As a result, you might need to either loosen the screw or tighten them, depending on whether or not it is running rich. In some circumstances, it makes no difference whether your engine operates with a rich or lean mixture. You need to adjust both screws before reaching the optimal setting.

Step 5: Adjust The Idle Mixture Screw

It is time to adjust your car's idle speed now that you have gotten the fuel and air mixture screws in good working order. The same procedure should be followed: adjust the idle speed in moderate increments until there is no shaking or misfiring from the engine.

After adjusting the screw by tightening it or loosening it, wait 30 seconds and then listen to the engine to check for any roughness. The effects of the adjustments shouldn't take all that much longer to become apparent.

If you are having problems obtaining the correct idle speed standard, you should consult either the owner's manual or a trained mechanic.

Step 6: Reinstall The Air Filter

After that, replace the air filter you initially removed in its housing and take the vehicle out for a drive. You have now successfully adjusted your Grand Wagoneer carburetor.

Carbon and soot can frequently accumulate in the carburetor while burning a rich air/fuel mixture, so keep a close eye on both of these substances.

Click here to view this carburetor on Amazon.

How Do I Know If My Grand Wagoneer Carburetor Needs Adjusting?

If you notice any of the following, you should get your carburetor checked and adjusted as soon as possible:

Difficulty In Starting The Engine 

If your Grand Wagoneer engine is not starting, the ratio of fuel to air in the engine may be off, which would explain why you are having difficulties starting it.

Having difficulties starting an automobile can also indicate that either the battery or the starter is on its way out. However, in some cases, the problem may be that the carburetor needs an adjustment.

Car Emitting Black Smoke 

There shouldn't be any dark smoke coming from your Grand Wagoneer's exhaust pipe. A rich mixture of gasoline and air produces black smoke when you accelerate. This indicates that the carburetor is consuming excessive fuel, necessitating an adjustment.


Other common signs that the carburetor needs adjusting are backfiring and overheating. A lean fuel mixture, the direct opposite of a rich one, might cause your engine to misfire or overheat. 

If your Grand Wagoneer engine is deprived of gasoline, it has to work harder to maintain speed, which reduces its performance, and since air is more, it causes the engine to misfire. So, the carburetor may need an adjustment.

How Do I Know If My Grand Wagoneer Carburetor Is Too Rich Or Lean?

Mechanic repairing the carburetor

There are several signs that will tell you whether your Grand Wagoneer carburetor is rich or too lean. 

Too Lean Carburetor

When a carburetor operates in a lean state, the fuel-to-air ratio is incorrect since the carburetor will deliver excessive air. The following are some of the typical signs of a lean mixture:

  • Backfiring engine
  • Lack of power during acceleration
  • Sputtering and popping sounds coming from the engine
  • Slow acceleration 
  • Spark plugs that are white or light gray
  • Poor engine performance

Too Rich Carburator

When a vehicle is said to be "running rich," it means that the vehicle's fuel-to-air ratio has an excessive amount of gasoline. The following are some of the typical signs of a rich Grand Wagoneer carburetor:

  • Bad fuel economy (car consuming excess fuel)
  • Strong odor coming from the fuel
  • Bad engine performance  
  • Black smoke from the tailpipe
  • Spark plugs blanketed with black soot
  • Active check engine light 

Do not disregard these warning signs. The efficiency with which your vehicle burns fuel and its overall performance will both suffer if you ignore these signs. Also, you may spend more buying gas. The wrong fuel/air combination can cause needless engine damage.

As a result, at the first sign of any of the above problems, it is important to either adjust your vehicle's carburetor yourself or take it to an automotive repair shop.

What Will Happen If The Grand Wagoneer Carburetor Is Not Properly Adjusted?

Carburetor without top cover

When making adjustments to a carburetor, the primary objective is to achieve the correct engine speed when idling while also ensuring that it operates smoothly.

When doing this, you are determining the correct fuel ratio to air while the engine is idling and establishing an excellent baseline for further tuning.

However, if the carburetor is not properly adjusted, the engine speed may not run smoothly and the carburetor will be operating on either too lean or too rich.

To Wrap Up  Jeep Grand Wagoneer display at a Chrysler dealership

To adjust the carburetor on your Grand Wagoneer, all you have to do is:

  • remove the air filter,
  • locate the adjustment screws,
  • check if the engine is rich or lean,
  • tune the carburetor,
  • adjust the idle mixture screw,
  • and then reinstall the air filter.

Don't hesitate to seek the help of a professional if you cannot do it alone.

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