Why does my Honda have a surging idle?

If you have a Surging idle on Honda, read this post. Most computer controlled vehicles rely on the coolant temperature sensor to tell the computer whether the engine is cold and needs a rich mixture. The computer then commands the idle air control valve to open to the correct setting. However, any vacuum leak in the system can screw this up.

How does a Honda car know its idle speed?

What you have is a computer that’s literally “chasing” a good idle speed. Techs call this a surge. Honda uses most of those same components to determine idle in their vehicle. However, they use a fast idle valve that has engine coolant running through it.

What does a fast idle valve on a Honda do?

Honda uses most of those same components to determine idle in their vehicle. However, they use a fast idle valve that has engine coolant running through it. Inside the valve is a wax pellet (just like a thermostat) that opens and closes a vacuum line that allows additional air to bypass the closed throttle plate at cold idle.

Why is the idle air control valve still open?

If the electrical connector to the idle air control valve is removed and the base idle screw is turned all the way in (count the turns if you’ve already adjusted base idle so you can return the screw to the proper position) and there is STILL airflow through the upper port, then the idle air control valve is stuck OPEN.

Where is the idle air control valve on a Honda?

5) Finally, check the idle air control valve. There’s a port in front of the throttle plate. That port feeds the idle air control valve and the base idle screw.

How to test the fast idle valve on a Honda?

3) Once the engine coolant is above 90 degrees F, you can proceed to test the fast idle valve. Start the engine and remove the vacuum line on the lower portion of the throttle body. Check for vacuum. There should be NONE.

What to do if your car Idles too fast?

If the lines are hot and you ARE getting vacuum on that removed vacuum line, you can suspect a bad fast idle valve. But continue with the tests before you replace it. 4) Make sure the base idle is set properly. Refer to the shop manual and set base idle according to the procedure. 5) Finally, check the idle air control valve.

5) Finally, check the idle air control valve. There’s a port in front of the throttle plate. That port feeds the idle air control valve and the base idle screw.

What to do if your fast idle valve is bad?

If there’s vacuum on that line, check the coolant hoses at the fast idle valve. They should be HOT. If the lines are hot and you ARE getting vacuum on that removed vacuum line, you can suspect a bad fast idle valve. But continue with the tests before you replace it.

What’s the idle code on a Honda Element?

Note: this a 2008 E, it has a slightly different TB than the ones on the thread about cleaning the Idle control valve. There is only 1 connector, 2 coolant hoses, and one vacuum line on it, that’s it. Now, it has a new problem, it idles around 1200, and is giving a P0507 (high idle) code.

Why does my Honda Civic have a high idle speed?

Check the coolant level, it might be low causing the intake air bypass thermal valve to cool off and raise the idle speed. This happened on my civic. If the battery is low or has an internal draw it could cause this. Also if the altenator is having problems, it could lead to a high idle.

Why is my Honda Element engine surging in Park?

Check all of the vacuum lines, and the small rubber cap on the under side of the intake manifold (tough to see). You could also try replacing the idle air control sensor~$75. Check the coolant level, it might be low causing the intake air bypass thermal valve to cool off and raise the idle speed.

What to do if your Honda has a bad fast idle valve?

There should be NONE. If there’s vacuum on that line, check the coolant hoses at the fast idle valve. They should be HOT. If the lines are hot and you ARE getting vacuum on that removed vacuum line, you can suspect a bad fast idle valve.

What to do if your Honda Civic Idles up?

Just pump your Gas Pedal a few times if you have ” Cold Starting Issues “…. But once your Engine is Warm / Hot, Idle will be ” NORMAL ” again. NOTE: That is the only ” DOWN FALL ” to this Bypass. B. Block Off By-Pass – You can make a Gasket and ” Block ” the 2 holes on your IACV and put the IACV back. It will ” NOT ” harm anything.

Why does my car run worse when the accelerator is not applied?

That increases the idle speed. Knowing that the accelerator isn’t being applied (by reading the throttle position sensor) the computer sees a high idle as a problem and commands the idle air control valve to close. That makes the engine run worse. So the computer either opens the idle air control valve again or adds fuel.

Why does my Honda Civic idle too high?

When cold you just get an idle that is too high like up around the 1200-1500rpm range or higher. The second video shows a vacuum leak that I found on a Civic using a ‘safer’ method for checking for vacuum leaks. Both work but the important thing is that you check for vacuum leaks if you have a Honda idle problem.

Why is my Honda Accord running at a low idle?

Vacuum leaks add too much air to the mixture causing the engine to run lean. The computer also fights them as it tries to maintain an idle using the IAC but it can’t keep up so you get a ‘hunting’ idle condition meaning that the idle fluctuates from high to low and it never levels out. This condition is often worse after the engine warms up.

How to fix a surging idle on a Honda?

How to fix a surging idle on Honda vehicles 1) Start by making sure the cooling system is filled with coolant and there’s no air in the system. If it’s low on… 2) Remove the air duct from the throttle body. Then start the engine and cover the throttle body with a solid object… 3) Once the engine

Why is my Honda Civic engine surging up and down?

#1- Cold Start. If you start the Engine and the Engine started Surging Up / Down ” Right Away ” during ” Idling “. A. Your IACV is either ” STUCK or BROKEN “. You can try to ” Unstuck it ” by cleaning it with Carburetor Cleaner to save $$$, after that put it back and it still not normal / unsuccessful, replacement is a must! #2- Warm / Hot.

Why does my Honda car run at high idle?

So the computer tries to compensate by adding fuel. That increases the idle speed. Knowing that the accelerator isn’t being applied (by reading the throttle position sensor) the computer sees a high idle as a problem and commands the idle air control valve to close. That makes the engine run worse.

How big is the engine in a Honda J30A?

Honda J30A engine reliability, problems and repair. In 1997, J30A engine was launched with the displacement of 3 liters. This is a typical 60° V6 engine with a compact aluminum cylinder block, its bore spacing is 98 mm, and the deck height is 235 mm.

When to change intake valves on Honda J30A?

In addition, you should adjust valves after every 25,000-30,000 miles. Here are the valve clearances for a cold engine: 0.2-0.24 mm for intake valves, 0.28-0.32 mm for exhaust valves. The J30A engine uses 240 cc/min fuel injectors. The firing order is 1-4-2-5-3-6.

What kind of timing does a Honda J engine use?

All J-series engines are gasoline-powered, use four valves per cylinder, and have a single timing belt that drives the overhead camshafts. VTEC variable valve timing is used on all applications.

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 to do about Honda engine hunting idle?

The most important part of the procedure is to back it off 1/4 turn after you bottom it out. You won’t find one of these on EVERY Honda engine BTW, mostly on engines older than 1997. The later model engines just use the IAC to control fast idle on a cold start up.

What does idle speech mean on a Honda Accord?

This one is more for a hunting or erratic idle, the original speech was for a ‘shaking’ or ‘rough’ idle. For that check out the other link about Honda idle issues or type ‘Idle Speech’ into the search function. Step 1 check for air in the cooling system.

What to look for in Honda Acura idle speed?

Here, we’re addressing that complaint and what to look for when you run into this symptom. Honda has a unique programmed response to excessive idle speed, resulting in the distinctive Honda idle ‘surge’. Don’t be a parts changer and replace the IAC motor! https://www.youtube.com/playlist?list…

What causes a surging idle speed on a Honda?

What causes a surging idle speed on a Honda or Acura? Here, we’re addressing that complaint and what to look for when you run into this symptom. Honda has a unique programmed response to excessive idle speed, resulting in the distinctive Honda idle ‘surge’. Don’t be a parts changer and replace the IAC motor!

When was the last time Honda idle issues were addressed?

This topic contains 9 replies, has 7 voices, and was last updated by Ariel 6 years, 11 months ago. PLEASE READ THIS FIRST BEFORE POSTING ABOUT HONDA IDLE ISSUES!!

Why is my Honda Civic having Idle problems?

Continue reading to find out what can cause your Civic to have idling problems. A car with a vacuum leak can cause an unstable idle. An unplugged vacuum line (as well as a damaged air intake hose) creates discrepancy between how much air the engine’s computer thinks it has, and how much it actually has.

How can I tell if my Honda Civic has a vacuum leak?

The easy way to find out if there is a vacuum leak is to spray the hoses with starter fluid or brake cleaner. Make sure this is done on a cool engine. If any of the hoses are cracked or not sealed correctly, they’ll suck in the vapor and the car’s idle will change. This should help you find the general location of a leak.

Why is the FITV valve on my Honda engine sticking?

If you continue to obtain different readings with the throttle released, suspect a sticking throttle shaft or faulty TPS. As another example, Honda engines (I believe 1996 and later) feature a FITV (Fast Idle Thermo Valve) that’s located directly under the throttle body. This valve is prone to sticking.

What should I do if my Honda Civic is running hot?

Inspect the engine. A Civic’s engine lies alongside the A/C setup under the hood, so if you can’t find anything wrong with the freon levels or the compressor, you may need to consider a different source. If you discover that the engine is running hot, its proximity to the A/C will negatively affect the system’s cooling capacity.

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