1. How does MS handle ignition control during cranking RPMs?
2. Is it possible to setup MS to "pass through" the ignition signal during cranking without any changes?
3. Once the engine is running, is it possible to setup MS to just take the incoming distributor signal and just add advance? Forget about dwell/spark changes and just let the incoming signal control durations and let MS control advance. The distributor signal was doing fine controling the coil directly prior to letting MS take control.
*My car was running great with MS controlling the fuel and the optical distributor controling the advance. Once I changed over to let MS control the advance, the car will not start.
*Don't get me wrong, I'm looking forward to programmable advance control with MS, but the cranking spark is wacked!
Jerry
Ignition/advance control during cranking RPMs
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Re: Ignition/advance control during cranking RPMs
2. Yes. Set to trigger rise. You will get spark during cranking based on where your trigger happens.
3. Not really. If Megasquirt is driving an IGBT type ignitor, it will always control dwell as well as advance. It may be possible to separate dwell from advance with an external TFI-type module. However, since dwell time plays into advance, why would you want to separate them?
3. Not really. If Megasquirt is driving an IGBT type ignitor, it will always control dwell as well as advance. It may be possible to separate dwell from advance with an external TFI-type module. However, since dwell time plays into advance, why would you want to separate them?
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jdkoontz
Re: Ignition/advance control during cranking RPMs
Thanks for the reply.
2. That only sets up the incoming signal detection. MS still changes dwell and spark duration which is not a "pass through".
3. Dwell and Advance are two sperate items.
Dwell is just one part of the ignition Cycle. The ignition Cycle time is limited by RPM.
Advance is the shift of the ignition Cycle in relation to TDC. IGBT is just a signal driver. It does whatever the CPU tells it to do. The entire ignition Cycle is computed by MS based on the RPM, input signal detection and several settings inside Megatune.
Jerry
2. That only sets up the incoming signal detection. MS still changes dwell and spark duration which is not a "pass through".
3. Dwell and Advance are two sperate items.
Dwell is just one part of the ignition Cycle. The ignition Cycle time is limited by RPM.
Advance is the shift of the ignition Cycle in relation to TDC. IGBT is just a signal driver. It does whatever the CPU tells it to do. The entire ignition Cycle is computed by MS based on the RPM, input signal detection and several settings inside Megatune.
Jerry