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94 Accord ex 4 cylinder idle surge and shifting issues

  #1  
Old 02-28-2012, 01:50 AM
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Default 94 Accord ex 4 cylinder idle surge and shifting issues

Hello well my car is doing some funny stuff. 1st the idle will surge mostly when the car is in gear with my foot on the brake. the rpm will only drop like 200 rpms and jump right back up. it is spaced out around 10 to 15 sec. when the car is in park the rpm is like 750 but when in gear it will be anywhere from 600 to 400 for the most part. Also if I am driving between 55 to 65 mph with an average rpm of 2000 the car hesitates to switch gears. But when I give it gas it will force it to the next gear. And when this happens if I hold the position of the rpm it remains constant. what I am feeling is like a small jerk. To me its like the car is confused on what gear it needs to be in.

Things I have done to the car in the last month are: cleaned the throttle body, IACV, EGR ports, Fuel injectors, replaced the PCV, TPS, Timing seals, Timing Belt, Spool valve filter,power steering pump. Any ideas would be greatly apreciated. Thank you
 
  #2  
Old 02-28-2012, 10:10 AM
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Look in the DIY section for a post by be about setting your "base idle".

Yes, your operating idle is OK at 750, but if your base idle is too low then your IACV runs out of range to open up when you shift it into gear. Go through the procedure - Honda idle-control system can mask some problems if it's not really set up.
 
  #3  
Old 02-28-2012, 11:36 AM
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Cool I will check it out. what about the shifting issues?
 
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Old 02-28-2012, 04:44 PM
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I got your PM about it not changing. If you unplug the IACV and the idle doesn't drop, then you should use the air-bypass screw (idle-adjust screw) to drop it down to about 550. If it won't go that low, you have a vacuum leak or some other issue.

The "base" idle is purposely low, because that causes the IACV to be partly open when it's controlling the operating idle. That way the valve is in the right place in it's control range & the system works better.

I'm no guru on automatic transmissions, so hope someone has advice on that. I do know that the throttle cable (from the accelerator pedal) has to have a bit of slack at idle. Then the shift cable (from throttle down to transmission) needs to cause the transmission lever to move immediately when the throttle moves. Possibly that adjustment is incorrect.
 

Last edited by JimBlake; 02-28-2012 at 04:50 PM.
  #5  
Old 02-28-2012, 06:20 PM
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well when I unplugged the iacv the rpm was already at 550 so I think the base idle is correct should have mentioned in the pm sorry. and I already did the adjustment on the cable and there was no change but I know that the tranny is good. so I think it has to do with the vss,tcm,or one of the two sensors on the transmission. I Had took it to the shop and the mechanic said that accord transmissions usually shift hard. I understand that but I know for sure that so much hesitation in area consistently is not normal. Thanks for your input
 
  #6  
Old 02-29-2012, 06:49 AM
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So the base idle is correct; and the operating idle in Park or Neutral is 750, right? So if the idle still drops way down when you shift into Reverse or Drive, then the IACV isn't doing it's job. Spray some TB cleaner through it? Usually they can be cleaned, but of course you might just need a new IACV.
 
  #7  
Old 02-29-2012, 08:41 PM
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Sorry, just me. I didn't see anything about the tune up items (plugs, cap, rotor, inspect the wires)?

When you did the TB cleaning, did you get the two ports to the "firewall" side of the TB?

Does, did the idle screw make any change in the idle-sometimes the little "port" can get clogged.

Sounds like you checked the throttle control cable for proper adjustment and movement (?). Check the mounts (mainly the frt and rear). When was the last fluid change and what fluid type of fluid was used?
 
  #8  
Old 03-01-2012, 06:01 PM
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Well once I unplugged the iacv and nothing happened I looked at the rpm and it was where it need to be so I didn't touch the screw. I did clean the ports as well when I took the tb off and cleaned them. I also just did replace my front mount the rear is a little weak but still in working condition. I did a fluid change like a week ago and I did the complete drain and refill of the honda specific tranny fluid. I figured out the transmission problem it was the soleniod.
but the idle is still off as for the tune up I did replace the sparks pulgs about a month ago. the wires seemed ok so I didn't replace them I had a brake and lamp inspection done around the same time and they said the rotors were good.
still looking for the idle problem though
 
  #9  
Old 03-01-2012, 09:57 PM
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Just a review...
Your operating idle is 750rpm when it's in PARK or NEUTRAL?
When you unplug the IACV it drops to 550rpm?

But when the IACV is plugged in and you shift into REVERSE or DRIVE, the idle drops low?
 
  #10  
Old 03-02-2012, 02:36 PM
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Yes, exactly, my operating idle is weird. sometimes it will be at 750 but it will almost always drop to 450 or 500 when I have the car in gear but when its in park it is at 750. when the car is warm and I come to a stop the idle will bump and what I mean is the rpm really wont change much but you feel the engine. the only thing that I havent done is the fast idle valve.
 

Last edited by seanmorley86; 03-02-2012 at 06:19 PM.

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