How Do I Tune My Carburetor

Posted in Fuel Systems & Components

I have a 1985 dodge ram d150. It has a 318 with a factory Holley 2 barrel carb on it. One problem is that it smells like it is burning a lot of gas, or running rich. It also only gets like 7 miles per gallon. It does have the A999 3 speed automatic transmission, but it should do better than that. Another problem is that it doesn’t have much power. It only has 83,000 miles on it, but you can put it to the floor and it speeds up, but not that fast. It doesn’t downshift into 2nd gear unless you’re going 35 miles per hour or slower. I was wondering how to fix these problems, and if it is the carburetor. Thanks.

There are 6 Answers for "How Do I Tune My Carburetor"

    1. Joe P says:

      You likely have something other than a carb problem. The only adjustment you can do on the carb is for the idle mixture but that won’t help your power issue. If you think the carb is not working correctly you could try to run some fuel cleaner through your gas tank but that’s never worked for me. Do you know if your spark plugs and wires are ok? How about your air filter? A vacuum line leaking?
      If you have the ability you could rebuild the carb Holleys are very simple to work on.

    2. Mdk68gto, Ase Certified M Tech says:

      Locate te mixture screws and seat them, after that turn them out 2 full turns. see how that reacts. a rich mixture can do both make a raw fuel smell amd effect power output. the low vacuum in the same situation can effect the trans.

    3. Eferrell01 says:

      Since the EPA started running the car business in the mid ’70s there are no adjustments on the carb except for idle speed. You need to get a good rebuilt one from your nearest auto supply store and be done with it.

    4. Doane_nut says:

      Make sure the automatic choke is functioning and not stuck closed.

    5. Don't Know Everything ! says:

      You may have a float with fuel in it or fuel soaked and hanging to low to stop the flow of fuel into the float bowls or dirt on the seat of the needle valve.

      The lack of kickdown is probably the linkage at the carburetor or transmission not being adjusted properly, get that taken care of ASAP or you will have transmission problems.

      Your lack of power could be fouled spark plugs from the constant flood of fuel.

      I would start with a carb overhaul kit and check the floats carefully when the carb is disassembled. Or if you have the money by an Edelbrock aluminum dual plane intake for a four barrel and an Edelbrock four barrel of no more than 600 CFM. You may need a linkage kit for the transmission kickdown but they are usually no more costly than a carb overhaul kit. The four barrel setup will give you better fuel mileage than a two barrel if you keep your foot out of it.

      The four barrel setup is definitely more costly than a carb kit or even a rebuilt two barrel setup but overall is a better setup than the two barrel.

    6. Dodge Man says:

      You need a good vacuum gage to use on one while your setting it,you set it to the smoothest highest amount of vacuum that you can get without it over loading on you,if done right you can make it run really good but its hard to do it by ear,good luck.