Results 1 to 10 of 10

Thread: stumbling idle after cold starts

  1. #1
    DX User
    Join Date
    Oct 2008
    Vehicle
    1989 Honda Accord LX-i coupe
    Posts
    19

    stumbling idle after cold starts

    The vehicle in question is an 89 accord lx-i coupe with 5-speed. There's around 215,500 miles on it currently.

    For the past week or 2, the engine seems to "stumble" after a cold start.

    Normally, the engine will rev to 1800 RPM, and gradually lower the speed to 750 RPM once it has warmed up.

    Now it will "stumble" around 1500 RPM, fluctuating within 50-100 RPM, with quite a bit of vibration. This only lasts for the first few minutes after the cold start. Once the engine has run for a few minutes, it manages to reach the usual 1800 RPM, and runs just fine.

    Here's the story of what may have caused it. I was starting it up one morning, and i realize that my radio faceplate was locked in the glovebox. So i shut the engine back off so I can unlock the glovebox with the key. Just as I was shutting the car off, this other car came out of nowhere, speeding down the street.

    Now, this caused me to flinch, and i managed to turn the key back to the "on" position just in time for the engine to start back up on its own. This is the exact moment when the "stumbling idle" first started.

    I checked the ECU LED and there are no codes flashing. My only guess as to what is causing the problem is that the engine has become slightly flooded, but I don't know enough to be sure. I'm hoping you guys have other ideas as to what the problem may be.
    Last edited by mrma5b; 03-24-2009 at 01:35 PM. Reason: No ECU codes



  2. #2
    3Geez Veteran MessyHonda's Avatar
    Join Date
    Feb 2006
    Vehicle
    89 LX-i(5speed)
    Location
    Bay Area
    Posts
    22,201

    Re: stumbling idle after cold starts

    yeah i would try to reset the computer...but it sounds like maybe its time to check your plugs and wires...also a buy seafoam and use it on your gas and brake booster

    1989 Honda Accord LX-i
    B18c1 swap since 7/2011
    175whp and 132tq
    Redzone tuned

  3. #3
    DX User
    Join Date
    Oct 2008
    Vehicle
    1989 Honda Accord LX-i coupe
    Posts
    19

    Re: stumbling idle after cold starts

    The spark plugs and wires were replaced a few months ago, but i'll check them when I get the chance.

  4. #4
    DX User
    Join Date
    Dec 2008
    Vehicle
    1989 Accord SEI
    Location
    So. California
    Posts
    12

    Re: stumbling idle after cold starts

    "it manages to reach the usual 1800 RPM, and runs just fine."
    Did you mean 800 RPM? As in Idle? I had a wire break to one of the temp sensors mounted in the thermostat housing that caused a similar problem ... just a thought. But I see that this thread is old and you probably found the problem and just and just bailed out on the post.

  5. #5

    AZmike's Avatar
    Join Date
    Jul 2002
    Vehicle
    Previous: '89 Accord LXi hatch, '89 Accord LXi hatch, '86 Prelude Si
    Location
    Tucson, Arizona
    Posts
    2,453

    Re: stumbling idle after cold starts

    Quote Originally Posted by Forrest View Post
    "it manages to reach the usual 1800 RPM, and runs just fine."
    Did you mean 800 RPM?
    Cold idle is 1500-1800 rpm. Warm idle is around 750 rpm.
    Mike

  6. #6
    DX User
    Join Date
    Dec 2008
    Vehicle
    1989 Accord SEI
    Location
    So. California
    Posts
    12

    Re: stumbling idle after cold starts

    "also buy seafoam and use it on your gas and brake booster"

    Sorry, new at this and don't know how to properly use the "quotes".
    How do you use Seafoam on the break booster? Just replaced my master, bled them and all doesn't seem quite right. The little gasket at the base was thrashed and I just shined it on. Is that important? Guess I should probably have started a new thread for this.

  7. #7
    DX User
    Join Date
    Oct 2008
    Vehicle
    1989 Honda Accord LX-i coupe
    Posts
    19

    Re: stumbling idle after cold starts

    Quote Originally Posted by Forrest View Post
    "it manages to reach the usual 1800 RPM, and runs just fine."
    Did you mean 800 RPM? As in Idle? I had a wire break to one of the temp sensors mounted in the thermostat housing that caused a similar problem ... just a thought. But I see that this thread is old and you probably found the problem and just and just bailed out on the post.

    I haven't found the problem exactly. The weather got warmer and the engine seems to cold start better now. It's probably that TW sensor acting up in freezing temperatures, but I don't have any error codes indicating the sensor has failed.

    Once the engine does reach normal temps, the idle goes to around 750 rpm, but I can feel occasional misfires as it idles. Once the car is moving and in gear, I don't detect any misfires. My best guess for that problem is slightly dirty fuel injectors.

    Warm starting is still somewhat of an issue, and always has since I got the car. Sometimes it will stall out if the engine was off for like 5 minutes and you try to start it again. Sometimes after starting warm, it will just idle roughly at like 300-400 rpm for a minute or 2. For this, it's probably a combination of the TW sensor and that main relay thingie, but I'm no expert.
    Last edited by mrma5b; 05-16-2009 at 04:52 PM.

  8. #8

    Dr_Snooz's Avatar
    Join Date
    Jun 2007
    Vehicle
    1989 Accord LX-i
    Location
    Fresno, California
    Posts
    10,638

    Re: stumbling idle after cold starts

    Quote Originally Posted by mrma5b View Post
    it's probably a combination of the TW sensor and that main relay thingie, but I'm no expert.
    Yep.
    Dr_Snooz

    "I like to take hammers, and just break stuff, just break stuff." - Beavis


    1989 Honda Accord LX-i Coupe, 240k miles, MT swap, rear disc swap

    Shop manual downloads available here: CLICK TO VIEW

  9. #9
    SEi User codyJDM's Avatar
    Join Date
    Apr 2008
    Vehicle
    '88 civic wagon
    Location
    SoCal
    Posts
    1,268

    Re: stumbling idle after cold starts

    Make sure your coolant is filled to the proper level and bled thoroughly. Air/bad coolant in your cooling system can cause you major headaches! Rough idle, bouncing idle, etc etc.

  10. #10
    DX User
    Join Date
    Oct 2008
    Vehicle
    1989 Honda Accord LX-i coupe
    Posts
    19

    Re: stumbling idle after cold starts

    Ok, so I tested the TW sensor using a multi-meter, and the sensor seems to be operational. I tested the resistance cold (weather is around 70 deg fahrenheit), and the meter read around 1.9 kOhms. I tested again after driving around and the temp gauge reached the middle of the normal zone, and the meter read about 0.4 kOhms. According to the chilton manual, these values are slightly higher than normal, but then again, I didn't do an exact measurement of temperatures. Should I replace the sensor anyways?

    Quote Originally Posted by codyJDM View Post
    Make sure your coolant is filled to the proper level and bled thoroughly. Air/bad coolant in your cooling system can cause you major headaches! Rough idle, bouncing idle, etc etc.
    The coolant level is correct, but I haven't done any flushing or bleeding of the cooling system. A new water pump was installed just before I bought the vehicle last July, so I don't know if the rest of the cooling system was serviced also. That'll be my next thing on my to-do list I suppose.

Similar Threads

  1. cold start issue - starts, idles, then dies =(
    By l75eya in forum 3geez Accords
    Replies: 8
    Last Post: 11-30-2008, 09:54 PM
  2. Only starts in cold weather.
    By EnSAn in forum EFI Tech
    Replies: 8
    Last Post: 09-16-2007, 11:28 PM
  3. oil filter blowing up on cold starts?????
    By 89T in forum 3geez Accords
    Replies: 41
    Last Post: 11-15-2006, 11:20 PM
  4. Runs on 3 cyls and burns oil on Cold Starts!
    By BootMachine in forum EFI Tech
    Replies: 4
    Last Post: 11-10-2003, 10:07 AM
  5. cold starts...
    By maka_RTH in forum 3geez Accords
    Replies: 10
    Last Post: 12-08-2002, 01:38 PM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
This website uses cookies
We use cookies to store session information to facilitate remembering your login information, to allow you to save website preferences, to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.
     
Links monetized by VigLink