What causes engine surging at idle?
If an engine is not getting enough fuel (this is called “running lean”), due to fuel pressure (regulated by the fuel pump and regulator), restricted fuel injectors, a vacuum leak or really anything that throws off the fuel mixture going in to the engine, this can cause the surge.
What causes RPM to fluctuate when driving?
If your RPM fluctuates while accelerating, it could be because your spark plugs have gone bad on you. Worn-out spark plugs can cause misfires to occur within your engine, and those misfires can lead to your engine vibrating a whole lot. Those vibrations can lead to the RPM in your engine going haywire on you.
What causes a 4 stroke engine to surge?
The fuel tank cap has a small hole, which allows air to flow into the tank and create back-pressure to help deliver fuel to the carburetor. Dust or dirt can plug up this hole. As a result, the carburetor won’t get enough fuel, leading to surging. Surging can also occur due to water contaminating your fuel.
What causes a snowblower engine to surge?
If the snowblower engine RPMs are surging up and down, check the following parts for damage: springs, gasket, carburetor, and spark plug. There are springs on the carburetor that allow the butterfly valves to open and close properly. The springs also ensure the governor is operating properly.
Why is my car surging at idle speed?
When an engine’s computer can “hunt” or “surge” at cruising or idle speeds it is searching for program compliance, there is a problem elsewhere in the system.
What causes hesitation and surging on Blazer 4.3L?
Fix Hesitation and surging on Blazer 4.3L If you have Hesitation and surging on Blazer 4.3L and it’s driving like a dog—poor acceleration, hesitation, or a surge and you suspect a fuel problem, you may be partially right.
What is the problem with the idle air control valve?
The problem may involve an annoying change (up/down) of engine speed while cruising at a steady pace, a low drop (or even cut-out) at idle or when approaching a stop, a wild high engine speed of several thousand rpm followed by a drop to near zero, etc. • Dirty/sticking IAC (idle air control valve) (P0505)
How often does the engine idle during a drive?
• The learned idling air flow volume remains at the maximum or minimum volume five times or more during a drive cycle. • After driving at 6.25 mph or more, the actual engine idling speed varies from the target idling speed by between 100 and 200 rpm, five times or more during a drive cycle.