Results 1 to 9 of 9

Thread: Handheld values were locked, engine backfiring.

  1. #1

    Default Handheld values were locked, engine backfiring.

    Hi Guys. I'm into my 7th year with my Atomic EFI TBI (purchased in May 2012) and couldn't be more satisfied. I haven't been on the forum in a while. Today I had just left the house to hit a cruise in and noticed some backfiring which got much worse before turning around and heading for home. The engine exhaust was extremely rich and almost died before getting it into the garage. I looked down at the handheld and saw that the values on the screen were locked in. The car's tach said about 500 RPM and the handheld read 1789 and not moving. Knowing that that was wrong I turned off the engine and it still read 1789. In going through the settings every one was at "0". I disconnected the battery and checked all of the connections, finding nothing I connected the battery and checked the handheld and all of the settings were back as I had them previously set. I then started the engine and now it's running fine. Has anyone had any similar experiences like this? I'm concerned that the ECU may be going bad. My Nova: 1970, 383 stroker, M20 4 speed, MSD 6A ignition box, MSD 8360 Ready-To-Run distributor.

  2. #2
    Join Date
    Oct 2018
    Posts
    28

    Default

    Hey. I never had to deal with the problem you described, but I have to mention that from time to time out of an unknown reason in my ECU the value for the total timing is set to 0°. So every time before I crank the engine, I power the system on and check the values if set correctly. Regards.

  3. #3

    Default

    That has happened to me as well, but this time was the first time that there was an operational issue. Today I swapped out the plug to the other connection port and the car started and ran just fine. Now we went out to another cruise in tonight and two diagnostic codes came in, the MAP sensor and low voltage came in the voltage was low at 5 volts even though the volt meter on the car read 13.2 volts. So I disconnected the battery and the codes cleared and it ran fine until we went home on the way the WBO2 sensor shows an error. I'm going to clean all of the electrical connections then replace the WBO2 sensor and see what happens. Does anyone have any suggestions on what else to check?

  4. #4

    Default

    Do you have the last firmware installed? Did you test your battery? Take a look at your rotor and see if the screws that secure it are not loose.

  5. #5
    Join Date
    Oct 2018
    Posts
    28

    Default

    Quote Originally Posted by joesjeep55 View Post
    That has happened to me as well, but this time was the first time that there was an operational issue. Today I swapped out the plug to the other connection port and the car started and ran just fine. Now we went out to another cruise in tonight and two diagnostic codes came in, the MAP sensor and low voltage came in the voltage was low at 5 volts even though the volt meter on the car read 13.2 volts. So I disconnected the battery and the codes cleared and it ran fine until we went home on the way the WBO2 sensor shows an error. I'm going to clean all of the electrical connections then replace the WBO2 sensor and see what happens. Does anyone have any suggestions on what else to check?
    All these things...
    1) 5 volts displayed although voltmeter read 13.2.
    2) MAP sensor error.
    3) WBO2 sensor.
    ...lead to either corroded or not optimal electrical contacts OR to a defective ECU as you already stated in the beginning of this thread.

    IMHO, I do not suspect MAP or WBO2 sensor to be defective. That's weird to me when two different sensors report an error so close after each other. Cheers, Roland

  6. #6

    Default

    Good point, make sense!

  7. #7

    Default

    Thank Guys, All of the firmware is up to date, I checked all of the connections and all are good I disconnected the ECU and visually looked to any oxidation on the connections there and they looked great. I disconnected the power and ground and cleaned them up even though they looked good as well. I put a dab of dielectric grease on all of the connections. Then I replaced the WBO2 sensor with a new one that I had on the shelf. I then fired up the car and it started right away. I then took the car for a ride, about 10 or 12 miles and it performed great. I started it 4 or 5 times with no issues. I also called tech support and no one has reported anything along the lines of what I was seeing. The only thing he suggested is to run the ground directly to the battery. I have it grounded to the engine block and has been that way for 7 years. I will move the ground as suggested and see what happens over the next several days and report back with the results. Have a safe holiday weekend.
    Last edited by joesjeep55; 05-23-2019 at 03:28 PM.

  8. #8
    Join Date
    Oct 2018
    Posts
    28

    Default

    Great news! Have fun!

  9. #9

    Default

    Hi guys. Now that I've driven a few weeks, in between the rain drops here in the South East, the Nova is running well with no hiccups whatsoever. I still don't know what exactly happened. Perhaps it's a combination of slightly corroded connections and a bad WBO2 sensor. As long as it's running well, I'm good. Have a safe summer cruise season.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us