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Is this my iacv idler air control valve, I think I gotta replace it because car is being crazy when I hit 50mph and idle is not so good cant gas it for sure

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Sounds like you have a couple of different problems. You shouldn't see IAC issues at 50mph, only at idle or when you're starting to accelerate, or decelerate. Issues like an erratic idle or intermittent stalling.

You might need to also clean your intake -idle issues could also be caused by a dirty throttle body.

Posted on Dec 31, 2012

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Idle air control valves, are designed to control the idle......But when they go bad { Ex: you sprayed carb cleaner into your throttle body, that will destroy it} and your on the freeeway they can cause a lack of full throttle.

Posted on Jan 01, 2013

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Posted on Jan 02, 2017

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SOURCE: 85 trans am 305 mpfi rough idle at start

check your Temp sensor for the ecu. could be out of spec at lower temps but not enough to send a code "You know -40 is possible and won't send a code"

Posted on Nov 12, 2008

  • 3 Answers

SOURCE: 01 s40 idle air control valve- hard to replace?

your IAC valve, idle air control valve is under the black plastic cover on the front right corner on the engine, remove cover undo valve, renew gasket and re install. ade 13 years volvo tech

Posted on Dec 02, 2008

  • 82 Answers

SOURCE: idle air control valve needs replacing

If it is the IAC then buy one. once you know exactly what it looks like then it should be easy to see it connected to your throttle body. Look at the new one to find out where potential bolt holes are and now you know where they are on the car as well. If the check engine light is still on after you replace it try disconnecting your battery cables for a few minutes and it should reset your computer and turn the light off.

Posted on Jan 05, 2009

  • 218 Answers

SOURCE: 2001 toyota echo engine light is on. Car idle is rough and sometimes stalls. Is there a way to clean the idle air control valve without removing it?

NO U HAVE TO REMOVE THE IAC TO CLEAN.DO U KNOW WHET CODE THE LIGHT IS SETTING?

Posted on May 05, 2009

ghost45
  • 1280 Answers

SOURCE: Replacing Idle Air Control Valve on '00 Sonata

No such code: P1520

Posted on Sep 23, 2009

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Code 0304&0505 skips runs better after idle


Trouble Code: P0304

Cylinder 4 Misfire Detected

Possible Causes:


Air leak in the intake manifold, or in the EGR or PCV system.Base engine mechanical fault that affects only Cylinder 4.Fuel delivery component fault that affects only Cylinder 4 (i.e., a contaminated, dirty or sticking fuel injector).Ignition system problem (coil or plug) that affects Cylinder 4.Trouble Code: P0505

Idle Air Control, Auxiliary Air Control Valve Circuit Malfunction

Possible Causes:


IACV-AAC valve control circuit is open or shorted to ground.IACV-AAC valve control circuit is shorted to system power (B+).IACV-AAC valve is damaged or has failed.PCM is damaged or has failed.

Feb 08, 2013 | 2002 Nissan Xterra

1 Answer

Car has in a fuel injected 1500 cc engine ,hard to start and uneven idle usually jump from 1500 to 3000 rpms when it should be idling


You probably have a bad Idle Air Control Valve (IACV). If it does not control the idle correctly , you can find yourself driving 50 MPH with out touching the gas pedal. The IACV is located on the throttle control valve and is typically held on by two or three small screws. The price for an IACV can run from $25 to $500. I purchased a throttle body for $40 , removed the IACV, and saved $400.

Dec 19, 2010 | Mitsubishi Lancer Cars & Trucks

2 Answers

Idle fluxuates up and down consistantly


Check the Idle Control System

Idle speed is controlled by the Idle Air Control Valve (IACV). The IACV changes the amount of air being bypassed to the intake manifold, in response to electric current controlled by the ECM. When the IACV is activated, the valve opens to maintain proper idle speed.

Symptom and Subsystems to Check:

1. Difficult to start engine, when cold--check Fast Idle Thermo Valve.

2. Fast idle out of spec, when cold:
a. Check Fast Idle Thermo Valve.
b. Check IACV.
c. Check idle adjusting screw (see Section C).

3. Rough idle:
a. Check hoses and connections.
b. Check IACV.

4. RPM too high, when warm:
a. Check IACV.
b. Check Fast Idle Thermo Valve.
c. Check hoses and connections, check Power Steering Pressure Switch Signal, and check idle adjusting screw.

5. RPM too low, when warm:
a. Idle speed is below specified rpm, with no load--check IACV and idle adjusting screw.
b. Idle speed doesn't increase after initial start up--check IACV.
c. Idle speed drops in gear (automatic transmission)--check automatic transaxle gear position switch signal.
d. Idle speed drops when AC is on--check air conditioning signal and IACV.
e. Idle speed drops when steering wheel is turned--check power steering pressure switch signal and IACV.
f. Idle speed fluctuates with electrical load--check hoses and connections, IACV, and Alternator FR Signal.

6. Frequent stalling, while warming up--check IACV and idle adjusting screw.

7. Frequent stalling, after warming up--check idle adjusting screw and IACV.

Additional Steps:

. Check Alternator FR Signal. Have alternator inspected, if idle speed fluctuates with electrical load. The FR signal communicates to the ECM how "hard" the alternator is working to meet the electrical demands of the car, including the battery and any loads which aren't monitored by the ELD. This square-wave signal varies in pulse width, according to the load on the alternator. The ECM places, approximately, 5 reference volts on the wire. The voltage regulator will drop this signal to approximately 1.2 volts, in proportion to alternator load. The ECM compares the electrical load (ELD) signal with the FR (Charging Rate) signal from the alternator and uses that information to set the idle speed and turn the alternator on and off. This helps fuel economy.

. Clean main ECM ground on thermostat housing.

. Reset ECM, by removing the 7.5 amp Back Up Fuse, in the under-hood fuse box, for 10 seconds.

. Replace PCV Valve, cleaning hose with brake cleaner spray.

. Substitute a known-good ECM. If symptom goes away, replace original ECM.

Check the ICM (Erratic RPM and PGM-FI System)

When the engine is cold, the air conditioner compressor is on, the transmission is in gear (automatic transmission only) or the alternator is charging, the ECM controls current to the Idle Air Control (IAC) Valve to maintain correct idle speed. Here's an overview of how the PGM-FI System works.

Background:

Various inputs to the ECM are TDC/CKP/CYP Sensor, MAP Sensor, ECT Sensor, IAT Sensor, TP Sensor, HO2S, VSS, BARO Sensor, EGR Valve Lift Sensor, Starter Signal, Alternator FR Signal, Air Conditioning Signal, Automatic Transmission Shift Position Signal, Battery Voltage (Ignition 1) Brake Switch Signal, PSP Switch Signal, ELD, and VTEC Pressure Switch.

Inputs are received and processed by the ECM's Fuel Injector Timing and Duration, Electronic Idle Control, Other Control Functions, Ignition Timing Control, and ECM Back-up Functions. These are the primary functional areas within the ECM.

Outputs from the ECM control Fuel Injectors, PGM-FI Main Relay (Fuel Pump), MIL (Check Engine Light), Idle Air Control (IAC) Valve, A/C Compressor Clutch Relay, Ignition Control Module (ICM), EVAP Purge Control Solenoid Valve, HO2S Heater, EGR Control Solenoid Valve, Alternator, Lock-up Solenoid Valve A/B (A/T), VTEC Solenoid Valve, and Interlock Control Unit.

Idle RPM:

Once you understand how the PGM-FI system is configured, it's easy to see how the ECM, Idle Air Control Valve, and the Ignition Control Module affect idle rpm. If the ECM's Electronic Idle Control function is not working properly, then it cannot properly control the IAC Valve. Likewise, if the ECM's Ignition Timing Control function is not operating properly, it cannot properly control the ICM (igniter). Obviously, idle rpm will also be affected if there's a problem with the IAC Valve or the ICM. As stated above, the ECM controls current to the Idle Air Control (IAC) Valve to maintain correct idle speed. This cannot happen if the IAC Valve is failing. The same situation exists if the ICM is failing. The ECM will tell the ICM to open and close the primary voltage circuit going to the coil and it won't respond properly. The result will be erratic spark plug firing and erratic rpm.

Conclusion:

If you are experiencing erratic idle rpm, try and isolate whether the problem is caused by the ICM (ignitor), IAC Valve, or the ECM. My experience has been that a failing ICM is usually responsible for the problem. Keep in mind that tachometers are connected directly to the ICM. Therefore, a fluctuating tachometer needle is often a dead giveaway. Heat and poor preventive maintenance (causing high secondary voltage to be discharge on internal distributor components) frequently causes the ICM (and coil) to fail. Besides performance, this is another reason why it's important to regularly replace spark plugs, spark plug wires, rotors, and distributor caps. Electricity will always follow the path of least resistance, even if it isn't the intended one. Our job is to ensure the intended path is the path of least resistance.

Ignitor (ICM) and Coil Replacement:

1. Disconnect negative battery cable.
2. Remove hex head machine screws, securing distributor cap to housing, using an 8 mm nut driver.
3. Move distributor cap and wires off to the side.
4. Remove machine screw securing rotor to shaft, using a #2 Phillips head screwdriver. It may be necessary to "hit" the starter once or twice, in order to rotate rotor for access to mounting screw.
5. Remove rotor and leak cover.
6. Unfasten ignitor wires, remove coil mounting screws, and set coil aside. Note: Removing coil first improves access to igniter.
7. Unfasten screws securing igniter to housing.
8. Remove ignitor from distributor and unfasten screws mounting ignitor to heat sink.
9. Coat back of new ignitor (or old igniter, if reusing) and male connectors with silicone grease. Silicone grease increases heat transfer to heat sink. Failure to apply silicone grease will cause the ignitor to quickly fail.
10. Mount ignitor to heat sink and reinstall ignitor, igniter terminal wires, coil, coil wires, leak cover, rotor, and distributor cap. Ensure female ignitor terminals fit snugly--crimp with pliers, if necessary.

AutoZone can test ICMs and coils for free. If you plan to keep the car, I would replace the ICM due the age of your Civic.

Sep 15, 2010 | 1991 Honda Civic

1 Answer

Engine starts, but won't idle, after I take foot off the gas


you may have an issue with the air idle control valve that allows air in the motor when you haVE your foot of the gas oedal. well it is actually an air pedal because it let more air in when you press on it and the computer gives it more gas. so if it runs and idles when your foot is on it and it won't if it is off then the air flow is getting cut off totaly and i would look at that idle air control valve or (iacv) good luck

Dec 26, 2009 | 1998 Ford Explorer

2 Answers

Honda Civic 1988 car, while running it will start to increase revs without touching accelerator


I have the same car and its the idler sensor. No big deal unless rev's past 2 grand

Nov 18, 2009 | 1988 Honda Civic 2 Door

2 Answers

My 91 acura integra is stalling after idling for just a few minutes. I just bought the car and it ran fine until just recently. I also noticed a gas smell after the car started again.


Idle is controlled by two main sensors: the FITV and the IACV. The FITV is a mechanical valve that is controlled by coolant temperature (there is no ECU plug to it). When the coolant is cold, the valve is open and letting air into the Intake Manifold through a hole in the Throttle Body above the throttle plate. This creates a small vacuum leak which in turn lets the motor idle higher than normal (supposed to be above 1K RPM for warming up). As the coolant warms up the valve closes and no longer lets air in through the hole in the throttle body. From this point the IACV, which is Engine Control Unit controlled, is letting small amounts of air into the Intake Manifold through another hole in the Throttle Body. Any amount of extra air the ECU is not expecting will confuse it and you will get either a high idle or a roaming/hunting/fluctuating idle. The principal of engine to operate is a need to have a Fuel : Air ratio of 14.6:1. You smell the gas after restart since the unburnt gas, when the engine dies, got pushed out through the exhaust manifold.
Th following are in order one after the other until it fix problem.
1- Find and replace the vacuum leak on hoses mentioned above.
2- Clean the the gunk built up at holes mentioned above.
3- Replace thermal valve at engine block identified by two vacuum hoses connecting to the Throttle Body.
Good luck.

Sep 28, 2009 | 1991 Acura Integra Hatchback

2 Answers

The car starts and immediately stalls unless I


Hey Jruthesq

The 850 is equipped with an Idle Air Control Valve (IACV) which supplies the engine with air when idleing (a necessity since the main throttle body valve is completely closed when no throttle is applied, thus the engine would lack air without the IACV when idleing). The IACV is suspended in a rubber mount on the front of the throttle body itself, and is easily removed and inspected/cleaned. If it's dead a good cleaning usually gets it going again. Also make sure that the air from the IACV is unhindered on its way from the IACV to the throttle body (it's actually common for the holes in the throttle body to be gunked up so bad by hardened carbon deposits that one sometimes needs a nail or even a drill to open it up again).

Just thought I'd mention this since you said that the gas needs to be feathered for the engine to start. When you press down on the gas the main valve in the throttle body opens up, closing the IACV and supplying the engine with enough air.

Oh and if your fuel pump relay is a green one marked 103 you should replace it with the new and improved red one. The relay is located under the fuse box cover under the hood. Remove the 4 torx srews holding the cover in place and you'll see the relays under there.

Good luck mate!

Jul 01, 2009 | 1997 Volvo 850

2 Answers

97 nissan pathfiner 3.3l idles too high


sometimes there is a secondary relay on the fender or firewall if there is that needs to be checked to see if it is getting the proper currentif so it more than likely is your sensor

May 27, 2009 | 1997 Nissan Pathfinder

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