What causes an engine to surge at idle?

A surge is usually caused by a fuel system management or drivetrain operation failure. 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. SPONSORED LINKS. Article published 2017-01-26.

Can a vacuum leak cause an idle surge?

Idle solenoids or controls should be adjusted to specifications after vacuum leaks are repaired. Ignition system problems can contribute to idle surge. Ignition timing and the condition of spark plugs and related components should be be checked before seeking professional assistance.

What does surge mean on a Mopar engine?

“It’s cycling between rich and lean conditions at idle,” explains Hayes. “You typically see it more with mechanically injected engines versus carburetors, but they both surge.” On a mechanically injected engine, which is the fuel delivery on the Mopar engine in the above video, when the engine richens up, the idle drops.

What should I do if I have engine surge?

Finding the cause of an engine surge problem can be time-consuming. However, some strategies can help you get to the root cause of the problem. Pay special attention to systems in need of maintenance, like ignition, fuel, the PCV, and air cleaner systems. Sometimes, a simple maintenance procedure can fix the problem.

What does it mean when your generator surges at idle?

An engine that is surging at idle is also known to be “hunting”. This means that it is searching, or hunting, for gasoline because the air to fuel ratio is too lean. Lean ratios mean that there is too much air relative to the amount of fuel.

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 should fuel Gage reading be at idle?

The 02 reading starts out at idle a little biased lean, but switching, then as soon as into accelerator truck stays lean until open loop. 58-65 mv is normal when leans out. Fuel gage never wavered at 12-13 psi.

Can a vacuum line cause an engine to surge?

Learn more Step 5 – If a vacuum line has caused a leak the engine will surge, as vacuum lines age they can become brittle and fall off the engine or accessory. Learn more Step 6 – If an air intake boot becomes torn and develops a leak it will cause the engine to surge.

What causes a car engine to start surging?

Vacuum Leaks. Vacuum leaks can cause surging on some engines, but it depends on the type of fuel injection system. The MAF (mass air flow) systems used on many cars measure the amount of air flowing through the engine’s throttle valve (throttle body) and use that information to determine how much fuel to inject.

What causes an engine surge when the ECU is off?

If closed TPS voltage changes, the ECU may assume that your foot is on the throttle, causing a richer fuel mixture to be delivered. This can also be caused by a faulty TPS, or even a poor ground. With the engine off, check TPS voltage with the accelerator pedal relaxed. Then work the pedal a few times and see if the voltage changes.

Can a bad throttle position sensor cause idle surging?

Idle surging can be caused due to other issues in the car, but if it happens in conjunction with other throttle position sensor symptoms, the culprit is often the TPS. At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges. 3) Check Engine Light

What causes an engine to surging when accelerating?

Vacuum leaks can cause car surging when accelerating on engines with either a Mass Air Flow system (MAF) or Manifold Air Pressure (MAP) system. Regarding engine surging while cruising, it depends on the type of fuel injection system. An internal combustion engine needs a mixture of air and fuel to create a combustion.

What’s the difference between a knocking and a surging engine?

“Surging” does not refer to a knocking engine or one that idles rough or stalls. 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.

Can a vacuum leak cause an engine surging?

Why does the idle surge when in neutral?

This went away the next day or so, but every time I’ve made that 4 hour drive, it happens for longer and longer each time. Now its really bad, and on top of the idle surging while the brake pedal is pressed, it ALSO idles really really high when in neutral and even sometimes surges but in fewer intervals when in neutral.

What to do when idle surges like crazy?

1. Warm up the engine completely. 2. Remove the intake boot at the front of the TB (throttle body). 3. Duct tape the big hole shut on the lower right hand corner in front of the TB plate/butterfly. Please make sure you clean where your gonna tape so the tape doesn’t get sucked in. 4. Connect the boot back.

Can a failed IAC cause engine stalling at idle?

A problem with the IAC should throw a P0505 code. A failed/problematic IAC can cause engine stalling when off-throttle, and/or excessively high engine rpm, particularly at idle. The IAC, signaled by the ECU, controls the throttle opening at idle.

How to fix idle surge in Ford Mustang?

Stop engine, disconnect negative battery cable wait 20 minutes to reset computer. Turn on headlights and tap the brakes a few times to drain the remaining power. I leave the headlights in the on position the whole time to make sure all power is drained to make sure the computer resets.

What’s the idle surge on a Ford EEC-IV?

Not just the Idle Surge (slight), But the throttle response improved quite a bit at .977v versus the .902v it was at. The Ford EEC-IV also recognizes a change over 1.2v to part open throttle. Closer to the .98v gave it quicker throttle response.

Why do I get Idle surge when I set TPS?

A lot of posts forget to mention is, you have to make sure your throttle body is properly adjusted then the TPS. If you just set the TPS and the throttle body is completely closed you will get an idle surge for sure, as the IAC is then compensating for your motor suffocating.

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.

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)

Why does my Jeep make a pulsing sound when I idle?

The car idles and drives perfectly at slower speeds but on the highway you can really feel the pulses and hear the exact making sounds. The only way to get the pulsing to stop is to give the jeep more gas. It sounds to me like its a missfire somewhere along the engine due to the fact that the exhaust is making sounds from the pulsing.

What causes the Check Engine light to turn off at idle?

At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges. The check engine light will randomly turn on and off even if the car is running smoothly without any jerks and stalling.

When does the Jeep Compass hesitate during acceleration?

Jeep Compass Engine hesitates during acceleration Inspection at your home or office. Our certified mobile mechanics come to you 7 days a week between 7 AM and 9 PM.

What causes idle surges on a car ECM?

Why does my Jeep WK2 surge while driving?

It mainly did it going up hill or at around 40 mph at 1300 rpms. Just like the WK2 guys with the 3.6 engine. They are experiencing something similar with having to adjust the way they drive due to lack if power and not so good tuning. It’s going to surge/buck regardless what you do because of lack of power and tunning.

What kind of engine does a jeep 4.6 have?

That’s only for the 4.6 and 5.7 Edit: Let me just say mine is going to buck/surge regardless what I did. I just had to adjust the way I drive it at certain times. It mainly did it going up hill or at around 40 mph at 1300 rpms. Just like the WK2 guys with the 3.6 engine.

Can a cracked IAC valve cause an engine surge?

If the hose is cracked or damaged, the engine will react as though the IAC valve is faulty. Also note that Toyota and Lexus vehicles may feature a non-motorized, magnetic IAC valve, requiring periodic cleaning of the IAC air inlet. In order to isolate the issue, clear any codes, then disconnect the IAC and start the engine.

When to set DTC for engine surge maintenance?

• 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. • If the actual idling speed varies from the target idling speed by more than 200 rpm five times or more during a drive cycle, the ECM illuminates the MIL and sets the DTC.

What are the symptoms of a bad idle control valve?

$0.00 1 Irregular idle speed One of the most common symptoms commonly associated with a problematic idle air control valve is irregular idle speed. 2 Check Engine Light comes on Another symptom of a potential issue with the idle control valve is an illuminated Check Engine Light. 3 Engine stalling

What should the fuel pressure be at idle?

Tested fuel pressure today at the filter. It is only reading 40 lbs at idle and it dips down to 34 or so when accelerating. I assume this is a fuel problem, but what is the problem and where do we start?

Is it normal to have a rough idle?

This is definitely not a normal situation. If you are experiencing a rough idle or your RPM is running high, then there are a variety of reasons for why this could be happening. It is not always easy to diagnose the cause because there are so many factors involved here. Below are the top 5 causes that a mechanic would look for.

What causes hard starting and rough idle on a Mercury?

Faulty Air Temperature Sensor: Will cause hard starting and rough idle. Air temp sensor should be checked with an Ohm Meter with a Cold Start Ignition Test. *ACU and PCU only. Incorrect fuel pressure: Can be caused by a bad fuel pressure regulator, or restricted return. On Laser EFI motors, look under the Fuel Pressure Regulator.

What kind of engine does a Mercury outboard have?

FIXED my rough Idle + stall problem 60HP EFI Mercury Outboard 2005 Four stroke engine! – YouTube

What causes an engine to surge when a vacuum line is torn?

Step 5 – If a vacuum line has caused a leak the engine will surge, as vacuum lines age they can become brittle and fall off the engine or accessory. Learn more Step 6 – If an air intake boot becomes torn and develops a leak it will cause the engine to surge. The air intake boot transfers engine intake air volume into the throttle actuator.

How to fix a surging engine in a car?

Easy step by step guide on how to repair an automotive engine that is surging, this information pertains to most vehicles and is listed in the order of popularity. Start with the vehcile on level ground, engine “OFF” in park with the emergency brake set, wear protective gloves and eye wear for safety.

What causes carburetor to not idle at high speed?

Engine will not idle Engine lacks power at high speed Idle sped is excessive Adjust idle mixture screw Carburetor out of adjustment Engine will not idle Idle speed is excessive Check for bent choke and throttle plates Engine will not start Engine hunts (at idle or high speed)

How to troubleshoot an automotive engine high idle?

The troubleshooting procedure for high and low idle conditions are similar, which are included in the following: Step 1 – If the check engine or service engine light soon has illuminated retrieving the diagnostic trouble codes could lead you in the right direction of what the problem is, or is related too.

What should I do about high idle surges?

P0507 – Idle Air Control System RPM Higher Than Expected. I would try doing an idle relearn first if you have this code or if you have a high or surging Idle. Works on most Nissan, Maxima, Morano, Altima, Sentra and more Idle Air, Volume Learn. 1. Make sure the accelerator pedal is fully released. 2.

What’s the idle RPM on a Nissan club?

My engine would rev between 1000 and 2000 (start at 2000, drop down to 1000, and rev up again, repeat) if in park or neutral. I heard this will happen after the clean. Engine stay at 1000 RPM in drive, with brake pedal pressed.

Why does idle not stable, surging, idle?

After doing it a few times, I still have the same issue. RPM constantly changing between 2000 and 1000, gear in P or N. (this engine surging issue happened before, not common, once in a while) It is not a major issue, as long as my MPG isnt affect (just topped up and will be monitoring that).

What should I do if my engine is surging?

There may be a fault in the computerized engine control system. Check engine control systems with a scan tool. Have a mechanic test the circuits and repair or replace components as required, since this is generally not a DIY job. The fuel filter may be partially clogged. This is an easy fix! The fix: Replace the fuel filter.

What does it mean when your car idles for a long time?

The idle of a car engine is kind of like a human heartbeat: You can tell what shape it’s in just by listening. Problems with idle speed —things like slow idle, fast idle, rough idle, or stalling after idling for a few seconds—are symptoms that something is wrong with your engine.

What to do if your engine spring breaks?

If the spring breaks somewhere in the middle it will affect both idle and power conditions. To test for this condition, remove ignition coil connector or ignition system or fuel pump fuse to disable the engine from starting. Remove valve cover (s) to gain access to visually inspect the valve train.

Why does the engine surging stop at idle?

If I put a load on the engine by turning on the airconditioning compressor, the surging will often stop. This is an intermittent problem but seems to occur at least 50% of the time and seems to be worse after the engine has warmed up. Thank you for any input. My car has 225000 miles. My car has a manual transmission.

What does it mean when your car engine is surging?

The slightest malfunction in any part will make an engine’s cycles deviate from what is optimal, impeding the engine’s performance. 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.

Can a vacuum leak cause engine surging when accelerating?

Vacuum leaks most commonly occurs in the hoses, which is most prone to wear and tear due to the under-hood heat from the engine. Vacuum leaks can cause car surging when accelerating on engines with either a Mass Air Flow system (MAF) or Manifold Air Pressure (MAP) system.

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.

Why does my car idle at 500 rpm?

Most of the time this is caused by either a vacuum leak or a dirty throttle body. I would then check the throttle body and clean it if needed. This is probably the most common problem.

What’s the idle speed of a Toyota Prius?

Fully warmed engine idles @ 800-900 rpm. When the AC kicks on it should jump up to 1000-1100 rpm… Yes, counterclockwise lowers the idle speed… It’s basically an air bypass valve. So tightening closes the valve and vice versa to increase idle speed….

What kind of idle problem does my Toyota truck have?

Discussion in ‘ Engine/Drivetrain ‘ started by lowlife, Oct 11, 2010 . So, I found that I have a rather complicated idle problem. Hope you guys have some input/ideas because I have no clue where to start. Here goes: Truck is a 92 22re with supposedly 105k miles.

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