Idle surge. No one likes it and can be bad enough to cause the motor to stall at not so great times. This is either a too lean, too rich or jumpy timing. Need to see what has changed since it idled correctly. Cam change is one of THE most common causes of idle surge.
Full Answer
What was your idle surge like?
My idle surge was similar to what others described here, where it would be fine after cold start, but begin to surge when the computer entered "closed loop". The surge was from around 500-1500, and would eventually stall without intervention. Closed loop is when the ECU begins reading the sensors, which is what pointed to o2 sensors.
What causes a diesel engine to surge at idle?
The appropriate fuel system cleaner added to the fuel tank can open clogged passages in injectors and carburetors that may be causing the surge. Any extra air entering the intake manifold will lean the mixture at idle and surging will result. A visual inspection of vacuum hoses may reveal cracked or leaking hoses.
Is a blower surge bad for the engine?
“It’s that constant hunting back and forth between rich and lean that causes the blower surge,” adds Hayes. “Typically, it’s not going to hurt the engine.” A number of factors can exaggerate or minimize the effect. Blower speed is one.
Does the engine surge on deceleration?
Now the car can move from open to closed loop on initial startup, and only has a little surge before finding a baseline. It used to surge on deceleration, which has completely gone away. However, if the engine runs for a few minutes, and is restarted before completely warm, it still surges until warm.
Is surging bad for engine?
While an engine surge doesn't cause your car to stop working completely, it can definitely negatively impact your fuel economy. Not only that, but the amount of emissions also tends to be much higher as well. Moreover, these effects tend to stack up over time when misfires happen more and more often.
What causes engine to surge 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.
How do you fix an idle surge?
How To Fix an Idle Surge ProblemDisconnect the air intake ductwork from the throttle body. ... Turn the engine off to allow the cleaner to soak into the IAC passageway. ... Restart the engine, rev and hold at 1,000 to 1,500 rpm, and repeat the cleaning process again.More items...
Can high idle cause damage?
Plus, excessive idling can damage your engine's components, including spark plugs, cylinders and exhaust systems. Because your vehicle's engine is not operating at its peak temperature when idling, fuel is only partially combusted, leading to a fuel residue buildup on cylinder walls.
What causes rpms to jump while idling?
Worn out or fouled spark plugs can cause rpm fluctuations. Check the engine vacuum and make sure there are no leaks. Leaks in the engine vacuum can cause rpm fluctuations. Replace the fuel filter if it is clogged or dirty.
What does engine surge feel like?
Basically, when an engine surges, you notice your car speeding up and slowing down even while you keep the accelerator steady. You may notice the tachometer fluctuating, for example, from 1500 to 2000 rpm. At the same time, you may feel a soft and rhythmic jerking motion.
How do you fix a surging engine?
Engine Surging: Low Pressure In Fuel Pressure Regulators First, inspect the fuel pressure using a fuel pressure gauge. Take the vehicle to a mechanic if the reading is low. You may have to replace or repair the fuel pressure regulator.
What is considered excessive idling?
Excess idling is defined as maintaining a stopped vehicle with the engine running for five (5) minutes or longer.
What RPM is too high?
Typically, engines idle at about 600-800 rpm. Older engines may go up to 1200 rpm or more while warming up. But if the engine is revving up while idling, even after it's sufficiently warmed up, you might have a problem. High idle speeds waste fuel, cause extra wear and tear on your engine, and can be unsafe as well.
What is considered a high idle?
High idle means a vehicle operating condition with engine disconnected from an external load (placed in either neutral or park) and operating at a speed of 2500 ±300 RPM.
What is it called when an engine is surging?
This issue is often referred to as engine surging, or rapid acceleration or deceleration cycles. You might come across either engine surging at idle or car surging while driving.
What happens if the EGR valve is stuck?
If the EGR valve is stuck open, exhaust gas cycle back into the chamber when they are not supposed to. The engine cannot combust on too much of the carbon dioxide in the exhaust gas, meaning there’s not enough oxygen for a combustion to take place. The EGR valve.
What does it mean when an engine starts easily and accelerates smoothly?
Engine surging is when an engine starts easily and accelerates smoothly, however after a few minutes at a steady speed, it either surges in speed or misfires. Misfiring happens when one of the cylinders of an engine’s combustion cycle fails. Since an engine has four cylinders, the car would still run if one cylinder fails.
Why does my car run rough when I drive it?
Since an engine has four cylinders, the car would still run if one cylinder fails. However, surging speed and misfiring both generally cause the engine to run rough, jerk, or buck. If you’re experiencing either, the first thing to do is to perform some inspection before heading to a mechanic.
When any one of an engine’s carefully controlled parameters deviates from what the Electronic Control Module expects, it
When any one of an engine’s carefully controlled parameters deviates from what the Electronic Control Module expects, it will automatically adjust air intake, fuel injection and spark plug timing to get everything back to how it should be.
Can a vacuum leak cause a rough idle?
Vacuum leaks in a MAF system will usually cause a rough idle, but often will not result in engine surging under cruise. Meanwhile, a MAP system extrapolates air flow from the intake manifold’s internal air pressure. A vacuum leak in a MAP system can cause engine surging while cruising.
What is blower surge?
Blower surge is one of those hot-rod dynamics that presents a paradox to enthusiasts. In one ear it sounds like the engine is struggling if not defective. Then the other ear is treated to a throbbing cadence of performance pulses that help define a unique cool factor that not everyone understands. On one hand blower surge can be so smooth ...
Do EFI engines have surge?
EFI engines with electric pumps and more precise fuel metering tend not to exhibit surge. Carburetors allow for more adjustment than mechanical injection, so there’s promise if in the right hands. “You can adjust the air bleeds,” adds Hayes. “A good carb guy can adjust it out.”.
Is a mild motor going to surge?
A number of factors can exaggerate or minimize the effect. Blower speed is one. Aggressive cam timing is another. “A mild motor is not going to surge while a full blown alcohol engine is going to have a bunch of surge,” says Hayes. “If it’s underdriven and guy’s running only five pounds of boost, it’s not going to surge ...
Can blower surges put a crying baby to sleep?
On one hand blower surge can be so smooth and melodic that it’ll put a crying baby to sleep. Or it can also drive a sane man into paranoia. “It’s typical that the guys who have it, don’t want it,” says Ron Hayes of The Blower Shop. “And the guys that want it, can’t get it.”. YouTube.
Why is my AC compressor not cycling?
Check to ensure your compressor isn’t cycling on and off due to low charge and/or the cut-off switch is defective. To troubleshoot, unplug your AC compressor and see if it makes a difference.
How many volts does a 2G alternator need?
If you still have an aging 2G alternator in your fox, check your voltage at 1000rpm, it should be at 13.8 to 14.2 volts. Low voltage (below 13.2v required to keep the battery charged) can cause a plethora of problems. Underdrive pulleys may also aggravate the situation.
Is it a good idea to ensure the electrical system is working properly?
This is a common issue, it’s always a good idea to ensure the electrical system is working properly and for that to happen, we need effective grounds. Here’s a link to help fix common ground problems.