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74 Cj5 Build

Discussion in 'Builds and Fabricators Forum' started by snoobly, Mar 31, 2020.

  1. May 2, 2020
    Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Silver Hill,...
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    Is this engine FI or just TBI ? If FI, The "reset " procedure I sent will work wonders for you. If no fuel injector's , Ed has much more familiarity with the procedures going forward.
    36 Degrees TDC, seems crazy high to me ...... But I like to be educated ?
     
    Last edited: May 2, 2020
  2. May 2, 2020
    Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Silver Hill,...
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    Did I see some where that you could not open this ? I pasted it here for you. It may not be applicable to your engine, though :shrug:
    "
    Your IAC and TPS are probably so far out-of-whack now that it might be a good idea to start from scratch.

    First, do the minimum idle air adjustment. This will also cause the ECM to reset the IAC:
    1. Warm the engine to full operating temps
    2. Turn engine off and then turn the key back to ON
    3. With the IAC connected, jumper pins A and B at the ALDL.
    4. Wait 30 seconds and unplug the IAC
    5. Remove the jumper at the ALDL
    6. Start the engine
    7. Adjust engine RPM to 500-550 in Drive using the throttle stop screw on the throttle body. 8. Shut the engine off and plug the IAC back in.
    9. Restart the engine
    10. Set TPS to .40-.44 volt or whatever your chip manufacturer specifies

    The above procedure should reset the IAC and get you close to final values. Then, to fine tune it, follow the procedure below:
    (note that everything below should be done with the car in PARK, not DRIVE)

    1. Start the car and get it up to operating temperature.
    2. With the engine-off, key-on, adjust the TPS per the GNTTYPE procedure so that you get the following on the Scanmaster: 0.40 to 0.42 volts with your foot off the gas pedal. Over 4.0 volts when you push the gas pedal to the floor. (note: many people say you need to have at least 4.6 or more volts when you floor the gas pedal. This is not true. Just make sure it's comfortably over 4.0 volts when you floor it. 4.25 volts would be fine. You should not have to ream out the TPS slots as is sometimes suggested. Try sliding the TPS all the way forward and then rotating it to achieve the 0.42 volts - this usually helps to get the highest WOT value possible.)
    3. After securing the screws that hold the TPS, start the car. Make sure that at idle, your TPS volts are BELOW 0.46 volts (I make sure mine are in the 0.42 to 0.44 range for a margin of safety). On most cars, the TPS volts jump by about 0.02 when you start the engine - i.e. if you set the TPS to 0.40 volts with the engine off, you will probably see it jump to 0.42 volts after you start the engine.
    4. Once the car is warm and in closed-loop, look at your IAC reading at idle. Make sure they are in the 15 to 40 range, with 20 to 25 being"perfect". If the IAC reading is too LOW, then turn the throttle body screw a little counter-clockwise (i.e. CLOSE the throttle plate a little more). If the IAC reading is too HIGH, then turn the throttle body screw a little clockwise (i.e. OPEN the throttle plate a little more). (Warning: if the TPS volts go over 0.45 volts while turning the throttle body screw clockwise, you are no longer in idle mode. Shut the car off and go back to Step 2.)
    5. Repeat Steps 2 through 4 above until you get the TPS and IAC readings to be in good values: TPS at 0.40 to 0.42 volts with the engine-off, key-on. TPS reading over 4.0 volts when you floor the gas pedal with the engine-off, key-on. IAC reading between 15 and 40 with the car running at idle, engine warm, in closed loop.
    It's an iterative process and takes a little time, but once you get there, you should have a good idle and minimize the chance of tip-in stumble. As others have mentioned, biasing the IAC to the low-end of the acceptable range might help improve your tip-in problem.
    One other thing to keep in mind - the exact IAC steps required to idle the car changes every day. If the incoming air is hot, it will open more to maintain idle speed (higher counts). If the incoming air is cold, it will open less (lower counts). So, if you set your TPS and IAC on a warm day, don't be surprised if the IAC steps are lower on a cold day, and vice versa. This is OK as long as they are generally in the ranges shown above.
    The good thing about the above is that it costs no money to do as long as you have a ScanMaster or some other tool. "
     
    Last edited: May 2, 2020
  3. May 2, 2020
    snoobly

    snoobly New Member

    Arvada, CO
    Joined:
    Feb 21, 2020
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    Noted on the code 51. I hard soldered the the adapter into the ECU and I have not been getting that code. I think it did have a loose connection.
    I ended up finding another small vacuum leak today. I fixed that, but I am still getting 0 steps on the IAC.
    I can't find any others.
    I am still reading lean all over the BLM chart. So I keep raising the VE table. Now I know that I am running rich because I am constantly backfiring.
    I had done some adjusting of the idle screw on the TBI unit when I first had got everything together. I am going to do the reset procedure that Lockman posted, maybe that's the source of the "leak" now.

    EDIT: I take that back on the code 51. I was out messing with the idle doing lots of little adjustments... I think sometimes the emulator gets mixed up or something. All I have to do to fix it is reload the Bin to the emulator and all works well.

    Lol I hear ya man! EFI is pretty interesting stuff and has quite the learning curve so far.

    Lockman, I only have TBI, not full multiport FI. Thanks for posting that procedure! I have seen that on Gearhead and I was using it pretty unsuccessfully when I had first started the Jeep. Now that I know there were some vacuum leaks and that they have been fixed, I am going to try this procedure again.
     
    Last edited: May 2, 2020
  4. May 3, 2020
    45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Naches, WA
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    As you work through your tuning efforts, would you mind posting your most recent .bin and log. I would like to follow along as your proceed.

    Also, here is another PDF that is geared a little more toward TBI. As you read thru the PDF, it noted a "Target Idle Speed". Your program uses the term in the tables as "IAC-Desired C/L Idle Speed" and notes a value of 700 rpm. So when manually adjusting the idle speed (IAC plug disconnected) you would be shooting for about 550-575 rpm.

    It is going to be interesting to see a log now that you have repaired vacuum leaks and completed the IAC reset.

    file:///C:/Users/Edward%20Stice/AppData/Local/Packages/Microsoft.MicrosoftEdge_8wekyb3d8bbwe/TempState/Downloads/Tuning%20the%20TBI%20(1).pdf
     
    Last edited: May 3, 2020
  5. May 3, 2020
    snoobly

    snoobly New Member

    Arvada, CO
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    you bet. I didn't record much yesterday. Did a lot of just toying with the tune and making small adjustments on the fly to see what would happen. I will try to get out today to do a couple of full logs. I am currently digging into things that would cause it to read lean even when I know I am dumping fuel in.
    One thought that rolled through my mind last night, the sensors are directly into the exhaust pipe, no "flow diffuser" or anything to slow the exhaust down at the WB02 or the main O2. Would anyone think that could be a culprit?
     
  6. May 3, 2020
    45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Naches, WA
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    No.
    This might be a better link to the PDF I noted.
    http://www.gmcmidwestclassics.org/Web pages/Tuning the TBI.pdf
     
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  7. May 8, 2020
    snoobly

    snoobly New Member

    Arvada, CO
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    Well, a small update to report. I will post the log at Gearhead, which isn't a great log because I didn't have all the things turned off that should be turned off when logging.

    I took Dave W's advice over at Gearhead EFI and bought a heated O2 sensor. While I was at it I had been doing some researching and discovered it is pretty critical that the WBO2 and the NBO2 be on different ground connections:whistle:.
    So I spent Tuesday evening after work wiring up the new three wire O2 sensor, cleaning up a couple of locations on the block so that each O2 sensor could have it's own ground. I also cleaned up D6 on the 7747 which is the ECM's O2 ground. It got too late on Tuesday night to fire it up, so I waited until Wednesday night.

    The second it started up I knew something had changed. Two reasons. #1. The WBO2 was now reading... WOO! finicky devices those thing are. #2. It sounded how a SBC 350 should sound!!! I pulled it out of the garage and took it up the road. My head slammed into the seat when I hit the throttle! It was awesome!! I can't believe how much more power this has than the old 258 I had in my old Jeep.
    For any of those curious, if you do the TBI swap and don't have to buy any tuning equipment, I believe I spent right around the $550 dollar mark. I easily spent $400 in tuning equipment though, so that makes the swap closer to the $1000 mark. Keep in mind that I had bought almost everything from the junkyard to start with, and then bought a few new items such a the O2, distributor, coolant temp, and oil pressure sending switch new.

    I'm mad at myself for wasting so much time and not just investing in the three wire right away. I am also mad because I know how funny electrical can be on a vehicle and yet I neglected to be sure my grounds were all adequate when installing the TBI system. Regardless, maybe someone else can learn from my thread here.

    Plenty more to do the the Jeep now that it is running like it should. I'll post updates as I mosy along! :beer:
     
  8. May 8, 2020
    45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Naches, WA
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    Glad to hear you have found the issue and have the engine running well. Dave W. always recommends a heated o2 and knowing some of the systems he helps with it certainly makes sense. In your particular case, you said your o2 was within a few inches of the manifold outlet so your o2 should have come up to temperature quickly. The biggest thing I noted, was you went back and cleaned up your grounds. It can not be stressed enough how important grounding is with EFI. A good read is the installation of MegaSquirt II that stresses good grounding and how to do it.

    I've never heard it stated or read for that matter, that it's critical that the WBO2 and the NBO2 be on different ground connections. Mine isn't, never has been and I have no issues with either o2 sensor. Actually, all of my grounds throughout the entire Jeep's electrical systems, ultimately terminate at the same lug on the engine.

    As you noted, the cost to do what you have accomplished can be relatively low. With the free tuning software available although most make the donation to the author, a cable to connect from ALDL port to a laptop and a Moates burn 2, I believe you total cost could have been held to about $700.00. With the emulator, that does account for increased cost.

    Again, very good. You should be proud of your accomplishments. :banana:
     
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  9. May 8, 2020
    snoobly

    snoobly New Member

    Arvada, CO
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    Funny how when you're cruising along with the install you think the grounds are good, but when you go back and look at them again you say "huh, what was I thinking".
    I would have thought it was close enough to heat up quickly, but maybe it wasn't. It was originally right at the exhaust manifold on the driver's side. I ended up plugging that one and moving it to the passenger side and about 6" away from the outlet. Maybe that was a mistake. The heated O2 fixed it now though. I'm just thrilled it is running how it should be!
    Thanks Ed, I appreciate your help and input along the way!
     
  10. May 8, 2020
    Dphillip

    Dphillip Member

    Omaha NE
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    Outstanding!
    Glad you sorted it out!
    I had a few issues with my TBI install years ago so I know how frustrating it can be.
     
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  11. May 8, 2020
    Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Agreed. Good Job..........I have learned that different set ups on these engines cause each engine to 'Like" different adjustments. It's like they are Individuals . Just Say'n

    Btw, was that ' Start Over Procedure ' any use to you ? I may just be for the 231 Turbo's ?
     
  12. May 9, 2020
    snoobly

    snoobly New Member

    Arvada, CO
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    I agree on how they all have their own personality. Yes, the procedure was helpful. I had actually seen very similar procedures posted on Gearhead EFI. I think some of the technical numbers might be different for different engines, but overall the procedure is the same. Thanks for reminding me of it!
     
  13. May 10, 2020
    Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Cool..... Glad to help.
     
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