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Thread: Timing Control No Start

  1. #11
    Join Date
    May 2019
    Location
    Ct
    Posts
    240

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    Maybe check the roll pin that holds the gear on?

  2. #12

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    Thank you all for the suggestions. I've thoroughly inspected everything again and I still can not find any problems. The distributor gear looks new and the pin is intact. The sliver of cam gear I can see seems OK too, but I can hardly imagine damaging the steel cam gear while not harming the bronze gear at all. The shaft turns very smoothly and the housing seems straight, but should I take additional steps to inspect for run-out or damage? I may be able to rig up a jig with a dial indicator. The reluctor to pickup gap is around .014". Does that seem reasonable? Different sources seem to claim .005" to .015"?

  3. #13

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    The magnetic pickup produces an AC sine wave signal. To test the signal connect your multimeter to the pickup wires and set to AC volts. There should be a voltage produced as the distributor shaft is turned, pulses on the bar graph display or the Hz setting will also confirm the signal. The reluctor to pickup air gap is OK.
    Last edited by tcm308; 06-01-2020 at 09:47 PM.

  4. #14

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    Very interesting information. I suppose the actual voltage value isn't too important? I wonder what the nominal voltage is supposed to be. Does the Minimum Signal Voltage setting govern this parameter? Will anything over that value trigger a spark?

    I'll try to manually trigger it and produce a spark this evening.


    EDIT: After some additional reading, I see that the voltage induced is directly proportional to the speed of the reluctor wheel. I bet this means the signal could read under 1 volt during cranking. Certainly easy to see why RFI interference can be such an issue. I raised the Minimum Signal Voltage slightly while reading through instructions from EFI System Pro, but I wonder if that has introduced potential cranking problems. I see I have a lot to learn on the subject.
    Last edited by K20BigBlock; 06-02-2020 at 07:55 AM.

  5. #15

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    Yes, the voltage value is important, but for what you're doing right now you, just need to see if it's still acting as a switch, turning voltage on & off. The Minimum Signal Voltage does not govern that parameter.

    Did you read this in the instruction manual?
    Ignition
    Ignition Type: This must be selected based on the crank signal that will be used. They consist of the following:
    • Coil (-) – Use if you are not controlling ignition timing, and are connecting to the negative side of the ignition coil and are not using a CD ignition box.
    • CD Box – Use if you are not controlling ignition timing, and are using a CD (Capacitive Ignition) box such as an MSD.Requires a square wave tach signal.
    • Magnetic – Use if you are connecting to a magnetic pickup. Does not matter whether ECU is controlling timing or not.
    • Ignition Reference Angle – This is the crankshaft position when the crank position sensor is triggered before TDC. A value of 50-60 is typical.
    • Minimum Signal Voltage – This parameter defines what the signal strength must be for the ECU to recognize it as valid for the crank, cam, and IPU speed inputs. Anything below this threshold is considered background noise. This value can be set between 0 and 5V. The higher the setting, the more noise is rejected and the stronger the signal has to be before the ECU considers it valid. Practically speaking, the sensor’s signal at the lowest speed (during cranking for instance) defines how high you can set this. Obviously, if you only have a voltage level of 0.5V during cranking, you do not want to set it to 1V because the actual signal will be ignored. It is advised to start with a value of .35 Volts. If there is a problem picking up a signal during cranking, lower this value .05 Volts at a time until you get reliable triggering during cranking (valid engine speed), then multiply this value by 0.75. If there is a problem with noise causing false pulses, you can try increasing this value.
    • Inductive Delay - This value is used such that ignition timing remains on target as RPM increases. If this value is too low, ignition timing will retard vs. commanded timing. If this value is too high, ignition timing will advance vs.commanded timing. Set this value such that the timing does not drift as RPM increases. It is best to use the “static timing set” function and set the timing to a fixed value such as 30°. Rev the engine up as high as possible (using appropriate caution/safety). Adjust the Inductive Delay value until the timing matches the commanded timing. Make sure you cycle the ignition key after this value is changed, before it is re-checked.
    • Filtering – This selection applies one of two different values to filter out electrical noise. The Base setting is high and should not need adjustment in most cases.

    That's a clue, you could have raised the Minimum Signal Voltage too high. (What do you have it set at?) I'd set it to .05V and if you still have the distributor out, spin it by hand and see if you get a cranking RPM, of course with the key on and the fuel pump off.

  6. #16

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    I'm kind of at a loss now. I was able to produce an RPM signal on the handheld just by spinning the distributor by hand. It even produces a spark as it should. That seems to point to a more fundamental mechanical problem? My mind jumped to the distributor green/purple wires being unplugged during cranking, but I'm 100% sure that I checked that connection multiple times.

    I absolutely confirmed the rotor spun when I turned the crank by hand just before removing the distributor. Back before I had upgraded the starting system I also specifically remember having oil pressure while cranking too. I did not think to check it again while trying to start it recently (there is a time gap of about 6 months since I had shut it down previously for the starting upgrades). Could my problem originally have been a weak starting system, but broke something mechanical during cranking with the proper starting system? Seems very unlikely.

    I welcome any ideas. I'm going to dig into it further when I get the time to reinstall the distributor.

    EDIT: To answer the previous question, I had the Minimum System Voltage set to .35V (I may very well have gotten that from the instructions, the time gaps during this build have clearly been disadvantageous), but I did not have to alter that value to get an RPM signal by hand.

  7. #17
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,741

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    You have oil pressure while cranking which proves the distributor drive.
    And you can produce spark while spinning the distributor by hand with the ignition on, which EVERYBODY should do on a new installation.
    I'd say your system has a voltage supply issue while the key is in the crank position.
    You need to verify module supply volts is above 9V in the crank position. Gary
    Regards, Gary

  8. #18

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    OK, I'll check that this evening. Thank you for the suggestion. Do both the battery supply wire and switched ignition wire need to remain above 9V during cranking?

  9. #19

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    Yes, they both do.

  10. #20
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,741

    Default

    Thank's for helping out. Yes, they both do. No spark while cranking if either drops too low. Ensure good grounding as well.
    Regards, Gary

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