Tip & How-To about Honda Civic

How to fix honda idle control solenoid

If your honda idles erratically then you can bet it is the idle control solenoid, but first check that there is no vacuum leak in the intake manifold.
Instead of getting one from a dealer or getting one from a junkyard which might be in the same condition that what is in your car, you can actually refurbish the idle control. It is because of all the times I have worked with honda with idle problems ( fuel injected models) It is due to corrotion in the idle control or blockage in the coolant passage. Here are some tips. If the car idles ok when cold but then it fluctuates when warmed up. That is due to blockage in the coolant passage. Either the little hoses that supply the coolant or the pipes or the blockage is in the idle control itself. Coolant must be able to circulate in there.
If the idle fluctuates warm or cold engine, then it is more likely the idle control is stuck in the open position. What happens is there is too much air bleeding into the manifol via the idle control causing the idle to go up, but then the computer senses it so it tries to bring the idle back down then lets it go and the cycle keeps repeating and you get an engine that idles up and down. The cylinder in the idle control must be able to move freely and it can be remedied with wd40. On blockage it can be cleaned with soft wire and flushed with water. When there is nothing binding movement and coolant can circulate in the idle control then it would work like it was new again.

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1990 honda accord surges at idle, what can cause this?

It is likely a vacuum leak (from a hose or the intake manifold), or a sensor is not working properly (like the throttle position sensor, MAF sensor, idle air control ).
Spray carburetor cleaner around suspect areas to find a vacuum leak. The spray will be sucked into engine and raise idle. Spray around the intake manifold where it mates to head for leaks there.
Also check for trouble codes. Maybe a sensor threw a trouble code.
Good luck.

Nov 30, 2011 | 1990 Honda Accord

2 Answers

erratic high idle

most of the time its the throttle pos sensor

Oct 13, 2009 | 1990 Nissan Sentra

2 Answers

2003 honda accord idle problem

clean your throttle body and check out the throttle postion sensor

Aug 09, 2009 | 2003 Honda Accord

4 Answers

My 99 Honda Accord keeps stalling after warmed up and relay for fuel pump starts clicking rapidly, what could cause this?

Low / uneven idle problem can cause by a lot of components.

Dirty air filter

Dirty injectors + o-rings

Vacuum leak at intake manifold and vacuum hose.

Bad Idle Air Control Motor (IAC)

Low compression (170 psi + is OK)

Start cleaning and repair these trouble spots and see is there any improvement.


For more advance DIY'er then you may try this.

Use a can of Berryman carburetor clean to locate the vacuum leak.


This is a 20-30 minutes job.

Vacuum leaks can occur in following locations.

Intake manifold AND/OR vacuum lines.

Intake manifold is not accessible unless the engine head if off.

You can still check the potential leak by spraying some Berryman near the intake manifold.

Listen for rpm increase after you introduce the Berryman (FUEL) at idle.

Do the same starting from the brake booster unit (the round unit) on the drive side fire all.

Carefully listen for increase of RPM right after to spray the Berryman to the potential vacuum spot.

Get a friend to HEAR the ROM increase or monitor for RPM on the tech.

DO NOT AIM the Berryman into any heat source.

PLEASE RATE my answer if it is useful to you.

Jul 25, 2009 | 1999 Honda Accord

2 Answers

code P505 - stalls when warm

Definite signs of intermittent vacuum leak downstream of the maf. Check for leaks from the air cleaner to the throttle and all hoses on the intake manifold. Also check for leaky intake manifold gaskets.
Do It Yourself Diagnosis and Repair

Sep 21, 2017 | 1997 Mitsubishi Galant

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