Page 1 of 2 12 LastLast
Results 1 to 10 of 17

Thread: Few Timing Control Questions (Not install related!)

  1. #1

    Default Few Timing Control Questions (Not install related!)

    So I noticed the timing bounces around at idle, but the second you give it gas, it goes right to its "cruise" map or commanded timing setting. The book confirms that is correct, but seems like it could go in live feed? Guess not. Would be nice to see actual timing like at idle.
    And on the "cruise" setting, can I go like 40°? (Reference is set to 50°.) And then I have my WOT at like 36°? Or does it need to be like lets say 30ish, and then WOT at 34°-36°? I'm thinking in terms of vacuum advance I guess in that it would pull to like 50+ degrees.

    And something unrelated to timing, but I need to add fuel to the accel pump, but is the correct menu the "Injector Pounds Per Hour" number, as in adjust that up or down? It's the only setting I see in the accel enrichment menu. I think it's like 48 lbs per hour or something. What would be a good amount to change? 1 lbs, 5 lbs etc. up or down?

    I also found the IAC hanging for a while on hot start. Found the setting to change that. Ended up at like .7 seconds so it ramps up and then comes down quickly. Can you change the RPM it goes to before ramping back down?

  2. #2
    Join Date
    Oct 2016
    Location
    Albuquerque, NM
    Posts
    69

    Default

    For the accelerator enrichment, page 29 of the instruction manual says,
    "Load acceleration enrichment:
    This parameter provides another way of adding fuel when the accelerator
    is depressed. It adds fuel depending on how fast the MAP sensor reading
    changes (detects a change in engine load). There is typically no need to
    adjust this parameter except possibly under some extreme conditions of
    vehicles that are heavy and under-powered. Adjustment values are in
    pounds of fuel per hour (PPH) and should initially be adjusted in
    increments of 5-10 PPH."

  3. #3
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    17,678

    Default

    Quote Originally Posted by zeppelin264 View Post
    So I noticed the timing bounces around at idle, but the second you give it gas, it goes right to its "cruise" map or commanded timing setting. The book confirms that is correct, but seems like it could go in live feed? Guess not. Would be nice to see actual timing like at idle.
    That's the "Idle Spark" control doing its job to stabilize the idle speed.
    Temporarily disable it when checking or synchronizing the idle timing.

    And on the "cruise" setting, can I go like 40°? (Reference is set to 50°.) And then I have my WOT at like 36°? Or does it need to be like lets say 30ish, and then WOT at 34°-36°? I'm thinking in terms of vacuum advance I guess in that it would pull to like 50+ degrees.
    This is user-programmable aftermarket EFI. The entire Base Timing Table can be edited/tuned. Download the Sniper EFI software (LINK).
    Except for the Sniper EFI software, the Base Timing Tables in the base calibrations (Terminator, HP & Dominator) are better than the typical centrifugal/vacuum advance curves.
    Using the Sniper EFI software (LINK), Target Air/Fuel Ratio Table (Fuel ICF) & Base Timing Table (Spark ICF), select "2D Table" Type (not "Simple"). The Base Timing Table can then be properly tuned for any engine.

    And something unrelated to timing, but I need to add fuel to the accel pump, but is the correct menu the "Injector Pounds Per Hour" number, as in adjust that up or down? It's the only setting I see in the accel enrichment menu. I think it's like 48 lbs per hour or something. What would be a good amount to change? 1 lbs, 5 lbs etc. up or down?
    See post #2 above.

    I also found the IAC hanging for a while on hot start. Found the setting to change that. Ended up at like .7 seconds so it ramps up and then comes down quickly. Can you change the RPM it goes to before ramping back down?
    The Startup IAC Position "Hold Time" & "Decay Time" are what control the RPM flareup upon starting.
    Please take the time to read the Sniper EFI Software Help File (LINK). It is very informative.
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  4. #4

    Default

    So what's the max cruise timing I can run? That's all I was really getting at.

  5. #5
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    17,678

    Default

    You can run up to 10° less than your Ignition Reference Angle. The ECU needs an Ignition Reference Angle, so it can control the synchronized Base Timing Table. The Ignition Reference Angle needs to be at least 10° higher than the maximum amount of timing used in the Base Timing Table. So 60° of Ignition Reference Angle allows 0°-50° of ignition timing in the Base Timing Table. 50° of Ignition Reference Angle allows 0°-40° of ignition timing in the Base Timing Table.
    http://www.masterenginetuner.com/top...all-fails.html (Crank Reference Angle Importance)
    If you're asking exactly how much timing advance your engine likes at cruise, you'll have to experiment with that. I run 40° of ignition timing advance at cruise.
    https://forums.holley.com/showthread...8640#post88640 (Target A/F Ratio Table & Base Timing Table Reference)
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  6. #6

    Default

    OK, so what about idle timing? What's a good procedure to determine your idle timing target? Vacuum gauge?

  7. #7
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    17,678

    Default

    Yes, the same way you did with a carburetor. Although, when programming the Base Timing Table, the initial & vacuum advance timing (full manifold vacuum) at idle, are combined in the idle area. See below.
    Most street performance engines will idle well with 15°-25° of timing advance. (Stock cam - 20°, performance cam - 25°, radical cam - 30°). The exact amount depends heavily on the camshaft specifications.
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  8. #8
    Join Date
    Oct 2016
    Location
    Albuquerque, NM
    Posts
    69

    Question

    So if I'm transferring my carbureted timing, do I include the vacuum advance on the cruise timing as well, since cruise uses vacuum advance? Or is it only included in the idle timing? My cruise with vacuum is in the low 40s. Thanks.

  9. #9
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    17,678

    Default

    Quote Originally Posted by bryaneh View Post
    So if I'm transferring my carbureted timing, do I include the vacuum advance on the cruise timing as well, since cruise uses vacuum advance?
    Yes, just like it would be with a centrifugal/vacuum advance distributor.

    Or is it only included in the idle timing?
    No.
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  10. #10

    Default

    Quote Originally Posted by bryaneh View Post
    So if I'm transferring my carbureted timing, do I include the vacuum advance on the cruise timing as well, since cruise uses vacuum advance? Or is it only included in the idle timing? My cruise with vacuum is in the low 40s. Thanks.
    DO NOT use the handheld timing setting option. It will lead to a stupid setup. Get the Sniper EFI software and build an advance curve. It's super-easy.

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