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Setting Base Idle speed

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  #1  
Old 03-12-2011, 07:32 PM
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Default Setting Base Idle speed

I was sure I had written this up before, but I can't find it...

This applies to Accords of the 1990 - 2002 range. Someone who knows more about earlier Accords, feel free to modify the range of model years.

Background:
Honda's idle-control system is a little bit finicky. It should be set up this way because otherwise the ECU will try to fight against any other adjustments. The "BASE" idle is a low idle, too low for normal operation. But it's the basis for the IACV to operate properly within it's control range.

Fix problems first:
- find & fix any vacuum leaks
- clean the throttle body bore & throttle plate
- clean the IACV and FITV (beginning 1998 there is no FITV)
- make sure the throttle plate closes completely
- - (mechanical stop-screw is only used to prevent it from wedging stuck closed)
- make sure the throttle cable goes a bit slack
- - (throttle cable is never used to adjust idle)
- make sure the cooling system has no air pockets (they confuse the system)

Find the parts first.
- Idle-Air Control Valve (IACV) is usually bolted to the back of the intake manifold.
- Idle-Air bypass screw is just above the throttle bore, recessed in a hole in the throttle body, it's usually a brass screw with a straight slot for a screwdriver. It has an O-ring that should be checked as a potential vacuum leak.

Procedure:
- Warm the engine up completely.
- Turn off all loads (AC, blowers, defoggers, stereo, EVERYTHING)
- Up to 1997; Unplug wire harness from IACV (engine will almost stall)
- - For 1998-2002; unplug the EVAP purge valve (see post #13 below).
- Adjust the idle-air bypass valve for 550 RPM
- - (PLEASE anyone with specific RPM for certain years chime in)
- Turn the engine off & plug everything back in

Now you should force the system to re-learn the idle behavior:
- Allow the engine to cool down completely
- Reset your ECU (different years pull various fuses)
- Start the engine without touching the gas pedal
- Allow it to run & warm up completely without touching the gas pedal

That should do it...
 

Last edited by JimBlake; 11-07-2019 at 10:58 AM.
  #2  
Old 03-12-2011, 07:33 PM
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Now for some specifics...

For 1998-2002 Accord, there is no FITV. That function is built into the newer version of the IACV.

Reset the ECU by pulling fuse #13 in the fusebox at the right-end of the dashboard (near the right door hinges).
 
  #3  
Old 03-12-2011, 07:36 PM
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For 2003 & newer (especially later when they have motorized throttles) the procedure is driven by Honda's proprietary scan-tool. Never done it, don't know whether there's a do-it-yourself way around that.
 
  #4  
Old 03-12-2011, 07:37 PM
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Someone please chime in if they know whether this applies to the V-6 cars or not...
 
  #5  
Old 03-23-2011, 09:10 AM
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This may be an unneccessary question however I am going to ask anyway. Is the process the same for all engines(4 cyl) or are there more specific steps for a f23a1 engine? I am trying my hardest to not sound too much like a noob .
 
  #6  
Old 03-23-2011, 11:15 AM
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It's good for the F23A1, including the reminder in post #2 that your engine doesn't have an FITV.
 
  #7  
Old 11-21-2012, 01:34 PM
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I should add that some F22B1's do not have an FITV. My 97 does not have one.

The factory manual for the 97 accords says
550 +/- 50rpm for F22B1 and B2
620 +/- 50rpm for F22B5 and F20B3
When setting the idle when the IACV is not connected.

When plugging it back in and restarting the engine it should be
700 +/- 50rpm for F22B1 and B2
770 +/- 50rpm for F22B5 and F20B3
 

Last edited by RobinsonRicer; 11-21-2012 at 01:37 PM.
  #8  
Old 11-23-2012, 01:27 PM
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Talking Hello!

Originally Posted by jcollins6
This may be an unneccessary question however I am going to ask anyway. Is the process the same for all engines(4 cyl) or are there more specific steps for a f23a1 engine? I am trying my hardest to not sound too much like a noob .
But Jcollins, with your one post, you are a Noob..

Welcome to the HAF..
 
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  #9  
Old 12-20-2012, 07:03 AM
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I want to than all of you for your support! The car is running very good, and i think it was the adjustment for the idle that did the trick. What a great bunch of people! I am so glad i joined this forum! Again, I thank you all for your support, Jerry.
 
  #10  
Old 03-23-2014, 09:43 PM
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will be using this info ASAP...thanks guys
 


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