1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Stumbling after valve cover job

Discussion in '1st Gen. Tacomas (1995-2004)' started by Just_Tombo, Jun 20, 2022.

  1. Jul 20, 2022 at 2:36 PM
    #21
    Just_Tombo

    Just_Tombo [OP] Well-Known Member

    Joined:
    Apr 20, 2021
    Member:
    #363252
    Messages:
    102
    Gender:
    Male
    Vehicle:
    2003 prerunner TRD DC 3.4
    All right guys, another follow up. As I mentioned a few posts ago, everything seemed totally awesome. The vacuum leaks were definitely solved, no doubt that there were at least one or two that showed up during my smoke test that were solved by the silicone vacuum lines that I purchased. However, there was still one symptom that occasionally popped up. Today, I believe I've solved the issue once and for all. Time will tell, and I will follow up.

    Anytime that I was on the highway going somewhere between 40 and 60 cruising in overdrive, if I started to go up an incline where the motor needed more power, a stutter would occur. It almost felt like a transmission stutter, as though the truck was trying to downshift to get more power. I did a search and found a thread where somebody had the same symptom, and there were directions for testing the transmission by lightly applying the brake. There is a sensor that you activate with the brake pedal that would stop the stuttering if it was in fact transmission related. For me, the brake pedal didn't stop the stuttering.

    In that same thread, it was suggested that the issue could be either coil related, or potentially a faulty spark plug with a crack in the insulator.

    By now a little frustrated to say the least, I bought a new set of spark plugs, as well as coils. My plan in doing the job was to take out the spark plugs one by one, and inspect them for possible damage. Turns out, my number four plug did have a crack that ran vertically on the insulator! This was the best news ever, because it seemed to indicate what My running troubles were being caused by. I skipped installing the coils because the crack in the plug is definitely worth playing out. I will return the coils. I buttoned everything up, all new spark plugs in place, and then I went back out to my default test place where I was able to replicate the stuttering multiple times during diagnosis. No more stuttering!

    I am not sure what happened to cause the crack in the spark plug that I had installed. The crack was so subtle that it only appeared when I rubbed my dirty fingers across it, and the dirt got caught in the crack. My guess is that it was already cracked when I got it, or potentially that it was cracked during transit. Suffice to say, I gave each of the new spark plugs the greasy finger test before cleaning them and applying fresh dielectric grease.

    Im Happy to admit that part of my repair was faulty if it means that the community gets to learn. I hope this thread helps somebody. I will check back in in several hundred miles to confirm that everything is good, but so far so good.
     
    Last edited: Jul 20, 2022
    TACOTU3 and Andy01DblCabTacoma like this.
  2. Jul 20, 2022 at 3:53 PM
    #22
    Morden

    Morden Well-Known Member

    Joined:
    May 28, 2012
    Member:
    #79669
    Messages:
    134
    Gender:
    Male
    Cali Central Valley
    Vehicle:
    2002 Tacoma TRD PreRunner
    Good idea but you may run into trouble come smog check time in CA, especially if they look under the hood.
     
  3. Jul 26, 2022 at 6:27 PM
    #23
    Just_Tombo

    Just_Tombo [OP] Well-Known Member

    Joined:
    Apr 20, 2021
    Member:
    #363252
    Messages:
    102
    Gender:
    Male
    Vehicle:
    2003 prerunner TRD DC 3.4
    After 600 miles driving to the Sierras this past 4 days, I can confidently say the problem is 100% solved. Thanks for coming along for the ride, hope this thread finds the people that need it.
     
    Morden, cruxofthebisquit and TACOTU3 like this.

Products Discussed in

To Top