How to adjust the idle speed on 1992 Dodge Ramcharger?

Turn the mixture screws in until the engine just starts to slow down in idle speeds and then turn out 1/4 turn

You have a vacuum actuated idle speed control. To adjust it, loosen the jamb nut and turn the diaphragm unit.
murf427

Too fast an idle speed. If an engine without computerized idle speed control is idling too fast and refuses to come down to a normal idle speed despite your best efforts to back off the carburetor idle speed screw or air bypass adjustment screw (fuel injection), air is getting past the throttle somewhere. Common leak paths include the carburetor and throttle body gaskets, carburetor insulator spacers, intake manifold gaskets, and of course, any of the engine's vacuum fittings, hoses and accessories. It is even possible that leaky O-rings around the fuel injectors are allowing air to leak past the seals. Another overlooked item can be a worn throttle shaft and a defective idle speed speed control motor/valve stuck in the extended (high idle speed) position/throttle position sensor. Also the throttle plate could be binding in its bore and kinked accelerator cable, coolant temperature sensor might not be operating properly misleading the computer that the engine is still cold and computer throwing fuel at it raising the idle speed.----------

Getting this possibilities checked will help.Thanks.Helpmech.

set timing on1987 dodge ramcharger 8 degrees BTDC (Before Top Dead Center) ..Each spark plug must fire 8 degrees before each piston reaches TDC (Top Dead Center).. This only holds true when the engine is at idle speed.. I hope this helps you set your timing.....

if the idle is to high then you have a defective part in the automatic idle speed control system or a leaking intake manifold gasket or a vacuum hose leaking, idle speed is not adjustable.

Check the shift cable attatchments for a secure fit. If loose it will not move into any other shifting range

2 airflow sensor out of operating range 3 coolant temp sensor out of operating range 4 oxy sensor indicates full rich 5 throttle potentiometer/airflow sensor... (low throttle pot signal with high airflow sensor signal) 6 throttle pot/airflow sensor...... (high throttle pot signal with low airflow sensor signal) 7 throttle pot...idle fuel adjustment failure(idle speed??) 8 intake air temp sensor...open or shorted circuit to sensor 11 Throttle pot at idle: Throttle pot idle trim out of normal range 12 Airflow meter: MAF signal out of range 14 Coolant thermistor: Resistance out of range or static during engine warm up 16 Air thermistor: Resistance out of range 17 Throttle pot: Out of range 18 Throttle pot/Airflow: Low throttle pot signal at high airflow 19 Throttle pot/Airflow: High throttle pot signal at low airflow 22 Fuel pump drive: ECU output to fuel pump relay 23 Fuel supply: Engine running too rich 24 Ignition Drive: ECU output to ignition Amp 26 Air leak: Engine running too lean 29 ECU self check 33 Injector Drive: ECU output to injectors 34 Injector: Looks for Injector dribble 37 EGR Drive: ECU output to EGR switching valve 39 EGR check sensor: EGR not working (normally pipe blocked) 44 Lambda (O2) sensor: Poor mixture control rich or weak (or misfire) 46 Idle speed Control valve: ECU output to Coil AB 47 Idle speed Control valve: ECU output to Coil CD 48 Idle Speed Control Valve: Stepper motor grossly out of position 66 Air pump: ECU output to air pump relay 68 Road speed sensor: Seen speed < 5km/h at high engine airflow 69 Drive/Neutral switch: Seen cranking in "D" or high airflow in "N" 89 Purge Valve drive: ECU output to purge valve
this is all I could find

have you checked the float adjustment ? this is a common problem for your type carb.

Before you start check the status of your choke. One that is stuck on will cause a high idle. If the choke checks out, proceed to the following:


You should have what's called a 2 needle carburetor. A larger screw adjustment for idle, and a smaller for high speed.

Start by adjusting your low speed (idle) needle until you reach the desired idle. I prefer about 850rpms. Do this with the engine running and adequately warmed so that your adjustments are not thrown off by the automatic choke.

Next slowly open up the high speed needle. As you open it your idle speed will gradually increase. Adust it in 1/8 turn increments, pausing after each adjustment to allow the changes to take affect. Keep opening it until you stop increasing your rpms, then take it back 1/8 of a turn.

Next readjust your idle mixture screw so that your idle is back down to 850rpms.

I cannot see how adding a fuel additive would help to be honest. I would be looking for a split or leaking vacuum line, I have even seen a leaking evap canister before that caused a similar problem. Does the engine pull clean and strong when it is warm or at cruising speeds? Does it feel like its running lean or misfiring?