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Tips For Starting Up A Rebuilt Engine With Sniper Efi

Discussion in 'Early CJ5 and CJ6 Tech' started by truckee4x4, Oct 9, 2021.

  1. Oct 22, 2021
    truckee4x4

    truckee4x4 Grant Kaye 2023 Sponsor 2022 Sponsor

    Truckee CA
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    Hey guys - we went over my wiring last night to get ready for tomorrow's startup, and it was suggested that I move the end of the (-) cable that runs from the battery. It currently goes from the battery post to the frame, and it was suggested that I move it to the threaded rod that protrudes from the starter housing at the front end. My starter is rebuilt OEM, the solenoid is new, and the starter does not have a hole in the housing to bolt to the bracket that goes to the block. The ground strap on the block goes between the upper bracket bot and the engine mount. Threaded post shown below.

    Thoughts?

    UNADJUSTEDNONRAW_thumb_816f.jpg
     
  2. Oct 22, 2021
    45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Naches, WA
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    I learned a long time ago when installing EFI on my jeep, that you are best served by attaching the battery negative cable directly to the engine block. From that connection, run a strap the the frame.
     
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  3. Oct 22, 2021
    Jw60

    Jw60 Sitting up n buckled down. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Sedalia MO.
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    I have battery negative to a bolt on the body then a positive negative pair to the alternator. I'm moving away from any component grounds on the frame since nothing electrical actually mounts to it, all motor or body tub for component grounds but will likely keep a ground strap on the frame.
     
    Last edited: Oct 22, 2021
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  4. Oct 23, 2021
    truckee4x4

    truckee4x4 Grant Kaye 2023 Sponsor 2022 Sponsor

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    Success! I have some videos to edit, here’s a couple of screengrab stills from just before the celebratory whiskey came out. oil pressure steady and RPMs around 2500.
    AC2E2C9C-E064-41CE-967B-1679510DF9F4.jpeg
    103AFF57-C375-46A9-96CE-A88F458AEC83.jpeg It took all day to prep, but we managed to get the engine broken in. The RPM bounces as expected, which will impede the IAC valve from achieving a nice smooth idle, which we will have to address down the road.

    After the break in we changed the oil with more break in oil and tried to turn it over again but my rebuilt starter wasn’t really cranking over the engine strongly enough so that was the only real hiccup of the day - I need to get a new starter. Once that happens we can proceed to dial in the final timing etc.

    I learned a lot today, including the importance of having a battery with 1000 cca, and a fresh, tested starter.

    Thanks to everyone who helped me and answered my questions in this thread!
     
    Last edited: Oct 24, 2021
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  5. Oct 23, 2021
    Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Whoohoo! :bananatool:
     
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  6. Oct 23, 2021
    OzFin

    OzFin Vintage Jeep Guy

    Michigan
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    Good job! :bananatool:
     
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  7. Oct 24, 2021
    Andrew Theros

    Andrew Theros Member 2023 Sponsor 2022 Sponsor

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    Right on truckee!
     
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  8. Oct 24, 2021
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Woohoo indeed! I hope you shared some excellent whiskey.
     

    Attached Files:

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  9. Oct 24, 2021
    skipilot

    skipilot Member

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    Outstanding!

    Tim
     
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  10. Oct 24, 2021
    jeep peep69

    jeep peep69 Member

    redding ca.
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    Nice.
     
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  11. Oct 28, 2021
    truckee4x4

    truckee4x4 Grant Kaye 2023 Sponsor 2022 Sponsor

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    Yesterday at lunch we fired her up again and tried to set the timing a bit better while at idle. I first drained the oil and replaced with fresh Maxima Break-In Oil and a new filter. As expected, the IAC in the ECU is still confused by the irregular tach signal from the HEI and the engine sounds not that great until it's somewhere around 1500. I thought you guys might like to check out a couple of quick videos I shot with my phone so you could see/hear:

    https://www.dropbox.com/s/z0nfy4rjmh..._0198.m4v?dl=0
    https://www.dropbox.com/s/imju37eafc..._0199.m4v?dl=0
    https://www.dropbox.com/s/d3whzimhik..._0201.m4v?dl=0
    https://www.dropbox.com/s/bfigf78tvb..._0202.m4v?dl=0

    So - time to put some effort into the crank trigger wheel. I have one designed, and have laser cut some prototypes out of wood, but I really need to take the fan and lower pulley off so I can more accurately measure the geometry of the balancer. Unless of course someone has one off a Jeep they would be willing to let me borrow for measurements....

    Bracket to hold the sensor, mounts to the Fuel Pump:
    Screen Shot 2021-10-28 at 7.20.30 AM.png
    Trigger wheel rough prototype, with holes every 30 degrees. The thing that I need to measure very accurately is the radial location of the holes out from center to as exactly match the holes in the balancer as possible so it is centered. One tooth will also be subtracted to allow the ECU to sense one revolution.

    Screen Shot 2021-10-28 at 7.20.51 AM.png

    I sliced my prototypes in half with the laser so I can place them on the balancer....they fit "well" but th eholes aren't yet right.
    UNADJUSTEDNONRAW_thumb_8198.jpg

    Closer view:
    UNADJUSTEDNONRAW_thumb_8193.jpg

    Another issue us that it seems as if the distributor wants to be clocked counter clockwise to achieve the optimal timing position of -6 degrees, and this causes the rectangular protrusion where the wires enter/exit the Cap to connect with the radiator hose. This will have to be addressed somehow. I wonder if I will need to modify this in some way so as to gain clearance.

    UNADJUSTEDNONRAW_thumb_82ca.jpg
     
    Last edited: Oct 28, 2021
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  12. Oct 28, 2021
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    There are three places on a full circle (every 120 degrees) where the distributor can be placed in-phase with the crankshaft. The rotor still points to the #1 wire at TDC of the #1 cylinder. Maybe one of these other rotations will allow the distributor to move to the needed advance.
     
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  13. Oct 28, 2021
    Norcal69

    Norcal69 Out of the box thinker 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Is there a way to tell the ecm the number of nodes on the trigger wheel, then allow the ecm to calculate the pulses?
    I think all you need is 3 nodes for RPM signal with a v6. If you look at the Holley trigger wheels they only use 4 nodes for a V8 engine. The trigger wheels that use nodes every 10 degrees are usually for systems with crank position sensors that are used with much more advanced systems. I believe that the Holley Sniper is a fuel only system and I think you are going to run way too rich.
    Just my .02, ple
    Your sensor bracket is going to sell like hot cakes on this forum if you choose to market them!!!!! Perhaps one could print it true to size, paste it to a piece of aluminum and cut it out!
     
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  14. Oct 28, 2021
    SFaulken

    SFaulken Active Member

    Bellevue, WA
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    You can reclock the distributor, to get the power connectors on the other side of the radiator hose. It just takes some fiddling sometimes with the HEI on an Odd-Fire to make sure it's "phased" correctly. Just a matter of taking the distributor loose, pulling it up to disengage the drive gear and oil pump, and rotating the whole thing counter clockwise, and dropping it back in. The distributor itself doesn't care in the *least* what orientation its in, as long as the terminals in the cap line up in the right places, so the odd-fire timing is taken into account.
     
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  15. Oct 28, 2021
    45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    You are going way beyond what is necessary for a crank trigger wheel. The trigger wheel you are trying to design would be great if the EFI were to be used to control the engine timing. Your Holley ERFI system will never be used to control your engine timing. Your HEI is controlling the engine timing. As was stated earlier, you just need a clean rpm signal to the EFI for the fuel only operation that it will be performing. For fuel only operation, it does not need to know nor care which cylinder is firing but rather how often the cylinders are firing, ie: an rpm signal.
     
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  16. Oct 28, 2021
    truckee4x4

    truckee4x4 Grant Kaye 2023 Sponsor 2022 Sponsor

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    I was pretty sure that everyone here at ECJ5 was adamant that there was literally ONLY one way to put a HEI distributor on our Dauntlesseses - with the #1 wire/post pointing at around 1:30 if you are standing at the LH fender facing the engine. This required filing off the corner of the intake manifold and installation of a button head hex bolt. I'd be happy to re-evaluate this if you guys think it's possible.

    I patterned this wheel off the Holley generic one (555-126). I know there is a member on here that succeeded in using three nodes (bolts through the balancer with round stock welded to them). I tried to copy that and decided I could get better accuracy with a wheel around the balancer face because I don't know how to use a lathe. Perhaps I'll try to redesign an alternate trigger wheel that only has three nodes. I do recall in paging through the Sniper menus that you can specify the # of teeth on the trigger wheel.

    Whenever I decide I have a final design, there are two shops in Reno that will water-jet one-off parts relatively inexpensively (Sendcutsend.com was $14 for one 0.25" sensor bracket in 5052, and also http://wademetalworks.com). I don't have the ability to CNC aluminum at the Makerspace for the sensor bracket. I think our CNC plasma table should be bale to do the trigger wheel out of mild steel with enough accuracy to work, but if not it would need to be water-jet cut as well.

    You are correct, and I understand that this is not about timing control but is about accurate RPM signal. Question - why would it matter to have a trigger wheel with three nodes and tell the ECU they are spaced at 120 degrees versus having teeth every 10 degrees and telling it that? I'd love to understand the difference.

    Over on the Holley forums, a member posted the following in my thread:

    I'm not buying it. If your Ignition Reference is unstable, you need to solve it. Are you telling me all odd-fire engines don't have a stable and perfectly separated firing sequence that doesn't support a steady crankshaft rotation at 800 RPM or so? The dist. is still forcing a trigger every 120° that should be smooth and even? Based on the timing light bouncing around, I think you have a distributor and or ignition system issue. Have you looked inside the distributor for loose or broken parts? Let us have a look at the datalog and GCF, there may be some clues in there that may help. You also may want to tidy up the wiring a bit before you make drastic changes. Any wire leading to the Sniper that is near a high voltage area is subject to disrupting the ECU.
     
    Last edited: Oct 28, 2021
  17. Oct 28, 2021
    SFaulken

    SFaulken Active Member

    Bellevue, WA
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    For the purposes of giving $random_internet_user a tutorial for installing an HEI on a Dauntless? That's certainly the easiest way to do it, and where people have the most success, it wouldn't be the "standard" procedure if it didn't generally produce satisfactory results.

    That being said, it's not the *only* way the distributor can be clocked. The odd-fire nature of the Dauntless just makes clocking it in other orientations somewhat of a pain in the arse, so most folks aren't going to, once they get it set in a spot where it runs right, and they just deal with any shortcomings of that orientation.
     
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  18. Oct 28, 2021
    Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    If you can specify the number of teeth, there is no reason not to do more for a smoother RPM signal.
     
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  19. Oct 28, 2021
    truckee4x4

    truckee4x4 Grant Kaye 2023 Sponsor 2022 Sponsor

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    I went back and read this old thread and think post #118 is relevant: New EFI Option - Looks Like 3 Good Players Now | Page 6 | ECJ5 (earlycj5.com)

    I have been running the GM TBI on my odd fire for about ten years now and am very happy with it. The GM TBI system fires the injectors each time the ignition fires, in the stock setup the ECM receives an rpm reference signal from the ignition module located in the distributor. The reference signal is a 5 volt square wave input to the ECM, so every time the ignition fires a cylinder the ECM receives a single 5v pulse and then the ECM fires the injectors. For fuel control the ECM doesn't know or care if it is getting an even or odd firing signal. You can use the tach signal from an HEI or negative post on the coil on a points system as a trigger, both these signals are on the primary side of the ignition circuit so the voltage is to high and dirty for an input to the ECM so it needs to be filtered and converted. Tach filters and signal converters are cheap about 40$ and will provide the ECM with the signal it needs. I think the tach output on the MSD box is 12v but I'm not sure, as long as the signal reflects the odd firing pattern you should be able to use a signal converter to drop the MSD output to the 5v signal for the GM ECM. Below are some scope captures the top capture show the relationship between the ignition reference signal, secondary ignition (cylinder firing) and the injector firing on a 1995 Chevy PU 5.7L. The second capture is from a 225 Dauntless odd fire and shows the uneven odd fire pattern.
    Hope this helps Mike

    Even Fire Chevy pickup:​
    IGN. REF1.jpg

    225 Odd Fire:
    IGN.1.jpg
     
  20. Oct 28, 2021
    45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    It is quite apparent the fellow over on the Holley forums does not understand the oddfire engine timing.

    I haven't set up a Holley system. I will look at their setup instructions to better understand how they use the ignition input signal. I see no reason to make the 10 degree wheel as opposed to the more simple 120 degree setup. Normally, the systems that utilize ignition input signals such as your 36 pulse wheel (or more) are performing much more control of both fuel and timing for things such as emissions throughout the rpm range and engine load.
     
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