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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 10, 2021
    skipilot

    skipilot New Member

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    Truckee, are you running some sort of a crank sensor for your EFI? I haven’t read all the EFI threads but from what I gather, the odd-fire 225 is problematic without some sort of a crank sensor so that the brain can get an accurate RPM signal. I may be wrong, but if that is the case, you may be better off doing your break in with the carb and then sorting out the EFI. Just something to consider.
    Tim
     
  2. Oct 10, 2021
    truckee4x4

    truckee4x4 Grant Kaye 2021 Sponsor 2020 Sponsor

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    To my knowledge, the EFI is capable of learning and running OK without controlling the timing (per the directions), albeit with less than ideal idle.

    To that end, I do have a Holley crank sensor, I have made ferrous triggers for the balancer, and I designed a prototype fuel pump plate-mounted bracket for the sensor. In my thinking I was going to dial in the timing mechanically first and then test and install the crank sensor setup.

    If you or anyone else thinks this is a bad idea let me know.
     
    Last edited: Oct 10, 2021
  3. Oct 10, 2021
    45es

    45es Member 2021 Sponsor 2020 Sponsor

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    No, you are not correct in assuming the ignition switch is out. That is your clean SOURCE of power for the EFI. The wire going to the HEI BATT terminal just happens to be the source of power for the HEI.
     
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  4. Oct 10, 2021
    45es

    45es Member 2021 Sponsor 2020 Sponsor

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    I think you are confusing a couple of issues. I believe skipilot's concern with the initial engine break in as apposed to ignition timing is so that when you do, first engine start, you can cleanly bring the engine up to RPM for cam break in and such. Since this is your first engine rebuild and startup, you do not need multiple issue to sort out simultaneously. As for engine timing, you will of course set that with your HEI distributor. The crank trigger will give the EFI system a clean signal which it will use only for the fueling of the engine.
     
  5. Oct 10, 2021
    truckee4x4

    truckee4x4 Grant Kaye 2021 Sponsor 2020 Sponsor

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    So do you think it’s worth trying to get the crank sensor going right away on first startup?
     
  6. Oct 10, 2021
    iharding

    iharding Quitter

    Tacoma, WA
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    The only advice I have is make sure it starts. I found it very stressful listening to my engine crank and crank and crank with gas washing the cylinder walls for what seemed like forever due to a dead brand new ignition module. I could easily have tested it but it was new!!
     
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  7. Oct 11, 2021
    45es

    45es Member 2021 Sponsor 2020 Sponsor

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    If you plan on using the EFI system rather than using a carb for your initial startup then yes set up the crank sensor. As noted by iharding, you want as clean a startup as possible.
     
  8. Oct 11, 2021
    truckee4x4

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    Well, I suppose I can certainly try. Getting the three trigger bolts that I made the specced 0.0040” from the sensor and securing them so they can’t rotate in the balancer and do any harm is going to be at (or beyond) the limits of my fabrication skills.
    5E64F8BA-2F0F-4641-A255-BCB5FBE4FB04.jpeg
     
  9. Oct 11, 2021
    45es

    45es Member 2021 Sponsor 2020 Sponsor

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    Well if you plan to use a crank with this system, do it now while everything is neat and clean with easy access. I believe another member said he would be willing to provide some help to accomplish the startup.
     
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  10. Oct 11, 2021
    skipilot

    skipilot New Member

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    Truckee, I don’t have any personal experience with the Holley Sniper or with any other EFI on the odd fire. I can put an engine together but would never claim to be an engine builder. The engine builders I have spoken to have all stressed how important the initial break in is. I have not done any serious research on EFI for the odd fire (I have converted a TR6 to EFI) just what I have casually read on this forum. If someone who has bolted a Sniper onto an odd fire can assure you it will start and run well enough to accomplish the break in then I’d be comfortable doing it. If I couldn’t find someone to give me that assurance I’d take the safe route and break it in with the carb, even if you had to run it from a boat tank with an electric pump. The only other advice I would have is take up the offer of help. The first time you do an engine break in can be a bit stressful as your trying to monitor all the vitals, look for leaks or other signs of trouble, and vary the rpms in the range the engine builder recommended. An extra set of eyes is really helpful. It’s very satisfying when it’s done and went well.
    Tim
     
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  11. Oct 11, 2021
    truckee4x4

    truckee4x4 Grant Kaye 2021 Sponsor 2020 Sponsor

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    @skipilot I'm not really sure that anyone else has done a fresh install/break-in with a Sniper before...but I could be wrong.

    FWIW I posted this question over on the Holley Sniper forums, and received what seems like an authoritative answer. I will also be calling Holley tech today and discussing with them and will see what they have to say.

    Sniper on fresh rebuild?

    Here is what was said over there - and I called Holley tech support and spoke with a very helpful tech named Tanner, who mirrored these instructions:

    Read the full manuals paying attention to the Wizard setup. Included in the Wizard is a target idle speed. Just like a carburetor, you won't have any idea if the idle screw is set properly but it's enough to get it started and you can then hold the throttle open to your ideal break in RPM range without any further adjustments. The Sniper has to have an RPM signal to even function, so it you wire it properly for HEI you'll get an accurate RPM signal on the handheld by definition. I wouldn't attempt any non standard crank/tach signal setup on an initial install because it may not work. Connecting to an HEI is a known quantity and there is no reason to deviate.

    This is a rough breakdown of the steps you would follow to start:

    1. Wire the system fully and properly. Temporary connections often introduce issues. For best operation use a relay triggered by known power source that it's hot in crank and run. Use this to trigger a fused supply directly from the battery to feed the pink Sniper wire.

    2. Test the fuel system by manually running the pump with a fused wire bypassing the Sniper. The Sniper will not run the pump until you run the Wizard. After the Wizard, the system will supply a prime shot and at this point you don't want any fuel in the engine. Confirm that there are no leaks and if you haven't done so, install a fuel pressure gauge on the inlet side of the Sniper to confirm that you have 60 PSI. After testing, wire the pump into the Sniper wiring and REMOVE the Sniper fuel pump relay.

    3. At this point you should be able to activate the Sniper. With the handheld in reach, turn on the ignition and confirm that the Sniper comes to life. If it does, run the Wizard following the instructions in the manual. Following the Wizard, you'll be asked to turn the ignition off for five seconds or so and turn it back on. The system will now have loaded the configuration into the Sniper and it should be ready to run. You won't hear the fuel pump run because the relay was removed.

    4. Use a timing light and crank the engine and confirm that your timing is set properly. After setting your timing, use the handheld again. Turn on the ignition, wait for the Sniper to boot about two or three seconds. At this point you should see "stall" I believe displayed on the Sniper. Crank the engine and first ensure that the Sniper doesn't reboot (the pink wire needs power in crank and run with no disconnect in between). You should see an RPM signal now displayed on the Sniper. Maybe 150 to 250 RPM. This confirms that you have a valid RPM signal from the distributor. If you don't, stop. There's no sense dumping fuel in the engine if there's no chance of it running.

    5. If you see an RPM signal, turn off the ignition. Reinstall the fuel pump relay. If you want to make sure it doesn't idle too low you can probably turn the idle screw in one turn but this shouldn't be necessary if you have your foot on the throttle.

    6. Turn on the ignition. You should hear the pump begin to run immediately. After about two or three seconds you'll also hear the injectors fire which means they're delivering a prime shot of fuel. If you have a helper, have them look down the Sniper when you do this first start just to confirm that fuel has been delivered. Crank the engine and enjoy. Move to the monitor functions on the handheld and watch AFR, CTS (coolant temperature), and RPM.

    Some suggest breaking in a motor on a carburetor, but sometimes there's no assurance that the carburetor is right. If you follow the conservative steps outlined above, it should start and run fine with a good AFR.
    So - is it possible to crank the engine with no fuel with just the starter, and set the timing?
     
    Last edited: Oct 11, 2021
  12. Oct 12, 2021
    Steve's 70-5

    Steve's 70-5 Active Member 2020 Sponsor

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    When I started my rebuilt engine I bought a cheap oil pressure gauge and hooked it up. Not a electric one but one that has a tube to the gauge. Prime the engine and watch the gauge and you will know when it builds pressure. This way you will not have to pull valve covers. I keep that oil gauge hooked up for a while. Start the engine with the distributor not to tight so you can adjust it. Have your timing light plugged up so you can check timing.
     
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  13. Oct 12, 2021
    truckee4x4

    truckee4x4 Grant Kaye 2021 Sponsor 2020 Sponsor

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    Yeah good idea thanks Steve. That was the type of oil gauge I had before and I still have it in a parts box somewhere, but last time I pulled it out the fitting that goes into the block was nowhere to be found. I currently have the port on the block plumbed to a 12V Equus oil pressure sender so I was actually going to connect it up to a gauge that's temporarily wired directly to a separate 12V battery so it can verify the prime before I crank the engine.

    I'm thinking I'll also have my IR thermo gun handy to take readings around the block and manifolds to check on those as well. I know the Sniper ECU reads manifold vacuum but I might plumb a gauge in as well.
     
    Last edited: Oct 12, 2021
  14. Oct 12, 2021
    skipilot

    skipilot New Member

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    Truckee, yes I believe you should be able to set timing by cranking the engine with the fuel pump relay unplugged. That is what I did when I converted the TR6 to EFI, though it wasn’t a Holley system.
    Tim
     
  15. Oct 12, 2021
    truckee4x4

    truckee4x4 Grant Kaye 2021 Sponsor 2020 Sponsor

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    Thanks. I've got a pretty good discussion going over on the Holley Forums, and one of the more knowledgeable members posted the same:

    And I think the other question that was not answered was in regards to fuel. Of many things that you shouldn't do on an engine break-in, you don't want to wash the cylinder walls with raw gas. So I suggest removing the fuel pump relay so the Sniper will not inject fuel until the time you are ready to start. The step running the pump to confirm flow and pressure will have flow through the Sniper, but because the injectors are not fired there won't be any fuel going into the engine.

    In the Sniper harness you'll find a fuse with a weather resistant cover and a fuel pump relay. Physically pull the relay from the harness. Anytime you're messing around with timing or sometimes when making tuning changes, it's a good idea to pull the relay. Every time you turn the ignition on after running the Wizard, the Sniper will execute a prime which is a shot of fuel to wet the intake and cylinders before cranking. Although it's possible to modify a tune to turn this prime shot off, it's much easier to pull the relay.

    The goal of the steps I outlined is to have the engine fire the first time it sees fuel with minimal crank time. Prime the oil system in advance and the only time you need to crank the engine is to check your timing and confirm that you have an RPM reading on the Sniper display. If you have a helper you can do those in one step. And you'll also be able to confirm oil pressure during the relatively short crank time.

    @skipilot - do you fly an aircraft with skis? I know quite a few bush pilots and heli ski pilots here in Truckee where I live, as I do some contract work seasonally in Alaska at a heli ski operation (Points North). - Grant
     
  16. Oct 12, 2021
    skipilot

    skipilot New Member

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    Yes, I have a PA-18 Supercub that is on wheels during the summer and skis for the winter. Flying skis is just fun.

    Tim
     
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  17. Oct 12, 2021
    truckee4x4

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    Nice! I'm heading out to my buddy Kevin Quinn's fly-in this weekend out in the desert north of Reno - High SIerra Fly In. I fly with him a lot and he has a really nice Carbon Cub, and he also has skis for his 1953 Skywagon. What year is your cub and where do you fly it?
     
  18. Oct 13, 2021
    skipilot

    skipilot New Member

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    My Cub is a ‘78 (pretty new for a Cub just like a ‘78 CJ5 would be pretty new). I live in Anchorage so most of my flying is within 2 hours of here, the Mat-Su Valley, Knik and the Lake George area, or down towards Homer and such. Occasionally I’ll get a bit farther out, across the Alaska Range towards McGrath or over to McCarthy and that part of the Wrangells. I just fly for the enjoyment and to see places you can’t get to other ways. For Alaska a Cub is kinda like a Jeep in the mountain West. One of these days I’d love to fly the Cub to the lower 48, a great way to see some country from a different perspective, low and slow.

    Tim
     
  19. Oct 19, 2021
    Warloch

    Warloch Did you say Flattie??? Staff Member

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    So as someone who has started a fresh engine with HEI and EFI, though not a Holley Sniper, I'll give you my $.02...
    • The oil pressure items are spot on for a motor that has been sitting and additives.
    • Plug the HEI vacuum advance and leave it plugged for the break in. It won't hurt anything at the 1500 - 2K RPM cam break in. Once you get it started go to @ 6 degrees and run it there.
    • Use the 'Stock' ignition and timing connection for the HEI to EFI. Folks have proven this works (on the Holley Sniper) and you just want to minimize the impacts and possible issues to trace for the break-in. Add the sensor in later if that's where your going.
    Minimize any items that would need trouble shooting if things don't fire and run right off the bat... KISS (Keep it Simple Stupid) is what my mantra is for these things.
     
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  20. Oct 19, 2021
    truckee4x4

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    Thanks Warloch. Good advice.

    Looks like Saturday is the day, and thankfully it looks like I may have a very experienced professional fleet mechanic buddy who used to build top fuel race boat engines coming over to run the show with me as his apprentice. He’s rebuilt plenty of engines before and has put a Holly Sniper on several vehicles so hopefully he can make it and things go smoothly. Will be taking lots of video!
     
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