What causes a car to hunt at idle?
Engine hunting and surging at idle is usually caused by a fuel delivery, air leak, or governor system problem. Cleaning/overhauling the carburettor, adjustment of the governor, and/or changing the air filer may be required.
What can I do about rough idle when warm?
If direct fuel injectors are the trouble-maker then, clean them using a blend of powerful solvents and high pressure. Another option to try includes fuel system additives, which clean fuel injectors. Note: An additive can sometimes, however, cause a rough idle problem.
How can I tell if my 280SL is running?
The first thing to do is check your linkages. Make sure the linkage going down to the injection pump is completly relaxed at idle. It should just fall on to the top ball without moving the pump lever. If that’s good then I would suspect the automatic choke on top of the pump. That’s the device with the two water hoses going to it.
What does it mean when your car is running at rough idle?
However, it is easy to recognize the problem, as during rough idling either the engine would run at an irregular rate or it may have varying RPMs without your foot on the gas pedal. So, once there’re visible signs of rough idling, trouableshoot the problem without causing any further delay. Beware If Your Car May Encounter This Problem.
What happens to an engine during idle hunting?
Idle hunting is the phenomenon during which the speed of the engine (in RPM) fluctuates from its mean position (i.e. the idling speed). If, during Idle Hunting the speed of engine exceeds the mean speed, more fuel consumption occurs. If, during Idle Hunting the speed of engine decreases below the mean speed, the engine will cut off. 4.1.
How does electronic fuel injection affect idle speed?
When engines had carburetors, they always provided a means of adjusting the idle speed. A simple turn of a screw corrected the problem if the engine’s idle speed was too slow or too fast. With electronic Fuel injection they eliminate the manual adjustment and the computer makes all corrections to the engine’s idle speed.
The first thing to do is check your linkages. Make sure the linkage going down to the injection pump is completly relaxed at idle. It should just fall on to the top ball without moving the pump lever. If that’s good then I would suspect the automatic choke on top of the pump. That’s the device with the two water hoses going to it.
How do you adjust the idle speed of an engine?
They use several designs, but most work in a similar manner. On early vehicles, General Motors often uses a stepper motor that turns a thread valve. Rotation of the armature moves the air valve in and out, adjusting the idle speed of the engine. The older Ford products more often use a spring-load plunger for the idle control valve.