The air to fuel adjustments on the front of the carburetor on my 1988 3500 with a 454 were adjusted and it is dieing every time i stop and loading up with fuel need to know the factory settings

If your air compressor trips off the moment it powers on, the issue is likely caused by trapped air over the pistons. To test for this problem, shut off the tank, unplug it from the power supply and drain the tank of all air.

How long since a tune-up? If your computer controlled, are there any applicable trouble codes?
With the vehicle in park or neutral not much load on the engine. There is a load when you put it in gear. Does the engine have decent compression? Is it running rich or lean? Could be other issues?

not important, what's important is that they are absolutely clean, including the four brass high speed jets located in the bottom center portion of the carburetor.

That model engine's carburetors has fixed jets, BUT if the slow speed jets are adjustable, earlier model carburetors have been installed. If so...................

The four adjustable needle valves control the flow of fuel in relation to the set air flow, adjusted as follows (if needed).

(Dual Carb V/4 With 4 (2 each carb) Slow Speed Adjustable N/Valves)
(J. Reeves)

The adjustment procedure of the carburetor slow speed needle valves follows. NOTE... if the needle valves turn too freely, replace the nylon bearing retainer (the nylon item at the front of the carb that the needle valve goes through first) with the newer type RED retainer #315232. If your engine has that weird linkage that connects all four of those needle valves, the newer RED retainers will enable you to discard that linkage. The RED retainers make it impossible for the needle valves to vibrate out of adjustment.

(Carburetor Adjustment - 2 Slow Speed Adjustable Needle Valves, each carburetor)

Initial setting is: All (4) Slow speed valves = seat gently, then open 1-1/2 turns.

Facing the carburetors, start with the top left needle valve, then the top right valve, then the bottom let valve, then the bottom right valve. It may be necessary to redo these steps to get the adjustments ideally set

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Do not attempt to gradually adjust all four of the valves at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

Please check the:
- Ignition system ( Ignition timing, spark plug cords, spark plugs gaps, vacuum advance actuator, contact breaker gap/ trigger gap).
- Fuel pump pressure (0.2 - 0.3 bar).
- Fuel system (for water contamination, carburetor clogged, element air cleaner clogged or fuel line obstructed).
- Clutch plate slippage ( for manual transmission).
- Brakes adjustment.

There are many things that could cause this problem,a misfiring cylinder ,low compression or idle speed not adjusted right,
Is this car fuel injected or does it have a carburetor?
if the timing is off, or the main problems i have seen are in the carburetor. does this car have an o2 sensor? a bad o2 can cause a bad fuel mixture and make engine load up at low idle speeds.
this car is a 1988 Camaro, what size engine , automatic or stick and is it carb or injection fuel?

you wont and you cant ,doesnt have a choke ,its computer controlled fuel injection

this helped me a lot

remove the breather cap look at the base of carburetor there are two small screws one is for gas the other is for air turn vehicle on and adjust screws to maximise both good luck

carb problem or vacuum leak at carb base gasket or intake manifold

Backfire in an automobile engine typically results from various malfunctions related to the air fuel ratio. Backfiring can occur in carburetor engines that are running lean where the air-fuel mixture has insufficient fuel and whenever the timing is too advanced. As the engine runs leaner or if there is less time for the fuel to burn in the combustion chamber, there is a tendency for incomplete combustion. The condition that causes this is a misfire. The result of a misfire or incomplete combustion is that unburned fuel or flammable hydrocarbons are delivered to the exhaust manifold where it may ignite unpredictably.


When starting an engine, timing that is too advanced will fire the spark plug before the intake valve is closed. The flame front will travel back in to the intake manifold, igniting all of that air and fuel as well. The resulting explosion then travels out of the carburetor and air cleaner. A common air filter will allow the gases to escape, but will block the flame front. On many small marine engines, no air filter is used, but a screen is placed over the intake of the carburetor as a flame arrest to prevent these flames from escaping the intake, and potentially igniting fuel, or fuel vapors in the enclosed sump or bilge of the boat and causing a fire or explosion. Improperly adjusted carburetors that create a lean condition during acceleration can cause the air fuel mixture to burn so slowly, that combustion is still taking place during the exhaust stroke, and even when the intake valve opens. The flame front can then travel up the intake and cause a backfire. In this situation it is conceivable that there is a backfire occurring in the intake manifold and exhaust manifold simultaneously.

Good luck and hope this helps, check the carburetor settings to make sure it's not running too lean and the timing . Keep me posted, be glad to help you get your RV running 100% again.