Basic Trigger

[ironwill11]

Hello,

I am not sure that i completely understand the basic trigger mode in TS.
I have it set to fixed advance at 10 degrees advance, the TS dashboard gauge reads out 11 degrees advance.

I am not sure what to do with the trigger wizard where it reads 0.0 degrees and says "match timing marks to this number". But if the megasquirt fixed advance is giving it 10 degrees my timing marks don't line up.

I am running a 4.3l TBI with MS2 board 3.0 firmware 3.4. The 4.3 does not have advance marks on the crankcase it only has marks for 0 degrees TDC.

Here is a video for the timing marks (I put white out on them see better):
https://www.youtube.com/watch?v=m6U3lXx3Kn0

My latest datalog with my father in law squirting starter fluid in the throttle body while adjusting the throttle to keep it running:

2016-10-20_19.20.53_whiteout.msl

MSQ:

2016-10-20_19.20.53_whiteout.msl

i have read a couple different manuals about the settings in basic trigger and I am not quite sure what things mean. Can anyone explain some of this stuff?

I would appreciate any info you can give me.

[jsmcortina]

With basic trigger and the trigger input happening at 10deg BTDC, you can't go less then 11 degrees of advance. You'll need to make some marks on the damper at e.g. 15, 20 degrees and strobe to those instead.

James

[Six_Shooter]

With basic trigger and the trigger input happening at 10deg BTDC, you can't go less then 11 degrees of advance. You'll need to make some marks on the damper at e.g. 15, 20 degrees and strobe to those instead.

James

Or get a dialback timing light...

You can get timing tapes that fit specific diameter dampers, to get even more accuracy, and is probably the way I'd go.

The Trigger Advance/Offset is where the base timing is, think of it like when you would disconnect the bypass on the stock (OBD1 GM) setup and set base timing, or on a carbed engine when the vacuum advance would be unplugged. That base timing number, on many engines is at or around 10*, is what you enter in this field. So if your dizzy is set to 10 degrees before TDC, then you put 10 degrees in this box, if the dizzy is 8 degrees base timing then you put in 8, etc. This tells the ECU that the trigger is coming this many degrees before the cylinder gets to TDC and uses it in it's calculations to ensure that the timing you are commanding is what is actually happening at the engine.

What year 4.3 are you using? What ignition system are you using? There's a couple different trigger designs and ignition systems used on the 4.3. I assume yours is a late model version that uses a crab cap type dizzy with a crank trigger wheel behind the front cover? Have you converted to an older HEI style dizzy?

More details about your mechanical setup will help get you to the settings that you need.

[ironwill11]

With basic trigger and the trigger input happening at 10deg BTDC, you can't go less then 11 degrees of advance. You'll need to make some marks on the damper at e.g. 15, 20 degrees and strobe to those instead.

James

Or get a dialback timing light...

You can get timing tapes that fit specific diameter dampers, to get even more accuracy, and is probably the way I'd go.

The Trigger Advance/Offset is where the base timing is, think of it like when you would disconnect the bypass on the stock (OBD1 GM) setup and set base timing, or on a carbed engine when the vacuum advance would be unplugged. That base timing number, on many engines is at or around 10*, is what you enter in this field. So if your dizzy is set to 10 degrees before TDC, then you put 10 degrees in this box, if the dizzy is 8 degrees base timing then you put in 8, etc. This tells the ECU that the trigger is coming this many degrees before the cylinder gets to TDC and uses it in it's calculations to ensure that the timing you are commanding is what is actually happening at the engine.

What year 4.3 are you using? What ignition system are you using? There's a couple different trigger designs and ignition systems used on the 4.3. I assume yours is a late model version that uses a crab cap type dizzy with a crank trigger wheel behind the front cover? Have you converted to an older HEI style dizzy?

More details about your mechanical setup will help get you to the settings that you need.

I have a 95 4.3l TBI with MS2 board 3.0, firmware 3.4
The 4.3 came with a 8 pin HEI module and a circular cap design.

I do have a dial back timing light (actually now I have both a simple and dial back type now). It is difficult to keep the engine running long enough to check timing because the injectors do not inject any fuel above the cranking threshold. Then when the RPM falls below the cranking threshold, the start squirting again. In the youtube video in an earlier post, it looked like I was advanced maybe 10-15 degrees. I have the number in TS set to 0.0 degrees as if I were setting the base timing on the 4.3. So from here I assume that the MS2 is advancing the timing 10 degrees (or 11 if that is the min) since the fixed advance is set at 10 degrees. So this should give show up on the dampener as 11 degrees advanced when I can get it to run (it takes 3 people, one to crank, the other to squirt starter fluid in the throttle body to keep it running, and I am checking timing and doing the data collection). I think this is what I want to see? I was wondering if I set the fixed advance to 0.0 degrees, match the number to 0.0 degrees then try to get it running the dampener should be right on the mark and then I can be certain the timing is correct?

[jsmcortina]

It is difficult to keep the engine running long enough to check timing because the injectors do not inject any fuel above the cranking threshold.

This may have been covered before. Are you sure these are low-impedance injectors? Have you tested the injectors using the test-mode?

Your "whiteout" datalog shows a normal injector pulsewidth. If there's no fuel coming out, it makes me wonder if they really are low impedance injectors or whether your injector parameters are set correctly.
High impedance injectors should have "PWM current limiting" set to "Off".
If these really are low impedence, try increasing the PWM Time Threshold to say 1.5ms and the PWM Current Limit to 75%.

James

[Six_Shooter]

I went back and watched the video. The timing looks to be in a good enough position to at least run, so now you need to figure out why fuel is going away.

You will always have spark when under the cranking threshold with the dizzy you are using. In fact you could completely remove the ECU from the vehicle and still have spark. This is the 8 pin module performing spark control, which is used for both cranking and in GM's Limp Home Mode, where the ECM would no longer provide any spark timing control and the engine would be on base timing. So I suspect that spark is going away above the start RPM threshold. It is this threshold that turns the bypass on or off. Once the threshold, in your case 600 RPM is crested, about 5 seconds later the bypass goes high which turns the module over to ECU timing control. FYI, set that to 400 RPM, since that's where most GM calibrations have it and is a good balance between actual cranking RPM and idle RPM. I use 400 RPM on both of my GM engines, a SBC and a 60* V6.

Do you have a WBO2 connected? In your MSQ you have it set to single wideband, but there doesn't seem to be any actual AFR data, since the AFR is flat at 17:1, even when the engine is running in the msl.

How have you connected the MS and the dizzy? What instructions did you follow?

What module are you using for the knock sensor? Your msl shows that you have 100% knock when the engine starts. I would disable any knock sensing until you get it running.

What board modifications have you done to set it up for your engine? Maybe some pictures of the setup would help.

This is very similar to my T-bucket for basic setup, just a difference of 2 cylinders, and an electric fan and no knock sensing on mine. lol

Do you have any composite logger or tooth logger... logs?

[Six_Shooter]

It is difficult to keep the engine running long enough to check timing because the injectors do not inject any fuel above the cranking threshold.

This may have been covered before. Are you sure these are low-impedance injectors? Have you tested the injectors using the test-mode?

Your "whiteout" datalog shows a normal injector pulsewidth. If there's no fuel coming out, it makes me wonder if they really are low impedance injectors or whether your injector parameters are set correctly.
High impedance injectors should have "PWM current limiting" set to "Off".
If these really are low impedence, try increasing the PWM Time Threshold to say 1.5ms and the PWM Current Limit to 75%.

James

All GM TBI injectors are low-Z.

But I agree, using the test modes is a huge help in diagnostics.

I just compared my settings to the OP's...

My current limiting setting is at 75%, with a PWM time threshold of 25.6 ms... where as the OP's is 30% and 1.0 ms respectively. There will likely be some issue here.

[ironwill11]

I went back and watched the video. The timing looks to be in a good enough position to at least run, so now you need to figure out why fuel is going away.

You will always have spark when under the cranking threshold with the dizzy you are using. In fact you could completely remove the ECU from the vehicle and still have spark. This is the 8 pin module performing spark control, which is used for both cranking and in GM's Limp Home Mode, where the ECM would no longer provide any spark timing control and the engine would be on base timing. So I suspect that spark is going away above the start RPM threshold. It is this threshold that turns the bypass on or off. Once the threshold, in your case 600 RPM is crested, about 5 seconds later the bypass goes high which turns the module over to ECU timing control. FYI, set that to 400 RPM, since that's where most GM calibrations have it and is a good balance between actual cranking RPM and idle RPM. I use 400 RPM on both of my GM engines, a SBC and a 60* V6.

Do you have a WBO2 connected? In your MSQ you have it set to single wideband, but there doesn't seem to be any actual AFR data, since the AFR is flat at 17:1, even when the engine is running in the msl.

How have you connected the MS and the dizzy? What instructions did you follow?

What module are you using for the knock sensor? Your msl shows that you have 100% knock when the engine starts. I would disable any knock sensor until you get it running.

What board modifications have you done to set it up for your engine? Maybe some pictures of the setup would help.

This is very similar to my T-bucket for basic setup, just a difference of 2 cylinders, and an electric fan and no knock sensing on mine. lol

Do you have any composite logger or tooth logger... logs?

I have actually run the engine with no ECU (MS2 nor factory) getting spark from the module. It seemed to start up and idle fine (just required someone to squirt starter fluid in the throttle body).

I will change the cranking threshold down to 400rpm. I wasn't sure were it needed to be and I know the engine likes to idle in the mid 600s.

I do have wideband O2 sensor on it. I bought an innovate MTX-L; unfortunately I had a problem that others online had. It wound up frying out less then a month on the install. The people at innovate took some time to get me a replacement and then told me that the wiring is very specific. I got the replacement but now I am hesitant since they wiring is not a simple as in their directions. I will probably try that again today, just don't want to have it break again. I was running the ground as megaquirt wiring suggests, but the innovate instructions want the power and ground to come directly from the battery with a relay from the ignition switch.

I have connected the MS2 to the dizzy. This adds a point of confusion that I will try to clear up. I bought my MS2 board 3.0 from DIYautotune and when it was packaged it had information for the old out of date firmware and manual. So the board was build as per the megamanual (as it turns out I can not use D14 for spark output, I have to use JS10). So I followed the wiring diagram to connect the dizzy from the diagram on the HEI 7 pin using the information on this page for the HEI 8 pin:

http://www.megamanual.com/ms2/GM_7pinHEI.htm

At this point I was still running an older firmware (2.9 I believe). Everything would run however, I could not get the idle below 1500rpm. Found out from Phil at DIYautotune that I was seriously out of date and now I am running firmware 3.4.2 and now have the current problem of not getting injectos to fire above cranking threshold.

As far as the knock sensor is concerned, I never set one up. I never ran any wires for a knock sensor either. I did not learn about that until after getting this all wired up. Should i be running a knock sensor?

I build the board according to the megamanual:
http://www.megamanual.com/ms2/V3assemble.htm

For the input section I built both the VR and hall/optical circuits and selected the hall/optical with the jumpers as recommended by the manual. I read somewhere that the HEI dizzy has a VR set up but the module converts it into a square wave. I will will go down to the vehicle and take some pics and maybe a video of the actual board and post it, maybe that will help.

I have an electric fan on mine as well. My fan is powered from the ignition switch long ago when my dad wired it. So if you watch any of the youtube videos I posted, that is the noise you here in the background before the engine starts. lol

By composite logger are you referring to megalog viewer? I general try to run a datalog on every test/start I can to see if it captures different information.

I love T-buckets!

[jsmcortina]

Having built your board with those other manuals is going to confuse things for sure.

Where is your spark output actually wired? Your settings says "D14" but you mention JS10. Also, D14 will need "Going Low" while JS10 will need "Going High"

The composite logger is covered in the TunerStudio Reference Manual, from the Manuals link above.

James

[ironwill11]

It is difficult to keep the engine running long enough to check timing because the injectors do not inject any fuel above the cranking threshold.

This may have been covered before. Are you sure these are low-impedance injectors? Have you tested the injectors using the test-mode?

Your "whiteout" datalog shows a normal injector pulsewidth. If there's no fuel coming out, it makes me wonder if they really are low impedance injectors or whether your injector parameters are set correctly.
High impedance injectors should have "PWM current limiting" set to "Off".
If these really are low impedence, try increasing the PWM Time Threshold to say 1.5ms and the PWM Current Limit to 75%.

James

All GM TBI injectors are low-Z.

But I agree, using the test modes is a huge help in diagnostics.

I just compared my settings to the OP's...

My current limiting setting is at 75%, with a PWM time threshold of 25.6 ms... where as the OP's is 30% and 1.0 ms respectively. There will likely be some issue here.

I got my settings from the megamanual as they made mention of the difference of having the flyback circuit installed. The TS reference manual says that 30-50% is typical for low impedence injectors. I am open to try anything, just stuck with these settings since that is what the megamanual stated for the active flyback circuit (not sure if the active flyback circuit is needed).

[Six_Shooter]

As James said, D14 is the default output and works. I use D14 on both of my installs currently, both are HEI, one is a dizzy, the T-bucket and the other is DIS, the Datsun, with a GM 60 degree V6 installed...

Anyway, D14 is the trigger to use, which sounds like you might need to change the board setup to do this. This could be another reason why you can't get the engine above the cranking threshold. Once the module switches to ECU control it looks for an input on the white wire to signal when spark should happen, with that setting wrong, there will be no signal here. I suppose for now you could change it to JS10 to quickly test...

The old way of getting the tach signal into the MS with HEI is to use the opto input, some people have experienced problems with this, even though the signal is indeed a square wave like you say, so the VR input has been used as an alternative, again, this is how I have both of my cars setup, using the VR conditioning circuit. This doesn't look to be a problem for you currently, because you are getting a tach input signal. Yes the dizzy has a VR sensor internally that feeds directly to the ignition module, which then changes the signal to be sent to the ECU.

The knock sensor is turned on in your MSQ, which is why I asked about your knock sensor setup. Disable that before more testing. It's not likely hurting anything at this point, but it'll be better to turn that off, if you're not using it.

Your E-fan is independent of the MS2? You don't have it set up under programmable I/O. The MS can control the fan for you, just FYI, if you don't have it currently connected.

Again, as James said, the composite logger is covered in the manual. It logs the tach input to see what exactly is happening, or not happening there.

[jsmcortina]

The "flyback circuit" didn't exist on the ancient V2.2 mainboard. You will have it unless it was intentionally missed off your V3.0 mainboard. Your reported symptoms of no fuel coming out suggest that your settings aren't working. Use the injector test mode, really, use it.

Because you built your board using the Megamanual, the tach input and ignition output are wired differently from the current standard. You must use the "Ignition capture" and "Spark output polarity" settings from there too that match your wiring. You also need to set JS10 as the spark output.
i.e.
Ignition input capture = Rising Edge
Spark Output = Going High
Spark A Output Pin = JS10

You could re-wire the board to match the current manual, but no particular need, so long as you use the above settings.

James

[ironwill11]

As James said, D14 is the default output and works. I use D14 on both of my installs currently, both are HEI, one is a dizzy, the T-bucket and the other is DIS, the Datsun, with a GM 60 degree V6 installed...

Anyway, D14 is the trigger to use, which sounds like you might need to change the board setup to do this. This could be another reason why you can't get the engine above the cranking threshold. Once the module switches to ECU control it looks for an input on the white wire to signal when spark should happen, with that setting wrong, there will be no signal here. I suppose for now you could change it to JS10 to quickly test...

The old way of getting the tach signal into the MS with HEI is to use the opto input, some people have experienced problems with this, even though the signal is indeed a square wave like you say, so the VR input has been used as an alternative, again, this is how I have both of my cars setup, using the VR conditioning circuit. This doesn't look to be a problem for you currently, because you are getting a tach input signal. Yes the dizzy has a VR sensor internally that feeds directly to the ignition module, which then changes the signal to be sent to the ECU.

The knock sensor is turned on in your MSQ, which is why I asked about your knock sensor setup. Disable that before more testing. It's not likely hurting anything at this point, but it'll be better to turn that off, if you're not using it.

Your E-fan is independent of the MS2? You don't have it set up under programmable I/O. The MS can control the fan for you, just FYI, if you don't have it currently connected.

Again, as James said, the composite logger is covered in the manual. It logs the tach input to see what exactly is happening, or not happening there.

I will go back and look at what changes need to be made to switch the input to D14. All of my testing/trying has been on JS10.

Yes, my fan is independent of MS2. I did this project over a decade ago with my dad long before I knew about MS. Eventually I will try to get MS to control the fan for me as well, but for now i have been trying things as simple as possible.

I will read more into the composite logger and figure that out.

Here is a video of the board (I think it is more clear then pics):
https://www.youtube.com/watch?v=CYZSk7SQijw

[ironwill11]

The "flyback circuit" didn't exist on the ancient V2.2 mainboard. You will have it unless it was intentionally missed off your V3.0 mainboard. Your reported symptoms of no fuel coming out suggest that your settings aren't working. Use the injector test mode, really, use it.

Because you built your board using the Megamanual, the tach input and ignition output are wired differently from the current standard. You must use the "Ignition capture" and "Spark output polarity" settings from there too that match your wiring. You also need to set JS10 as the spark output.
i.e.
Ignition input capture = Rising Edge
Spark Output = Going High
Spark A Output Pin = JS10

You could re-wire the board to match the current manual, but no particular need, so long as you use the above settings.

James

Thanks for the input, I have these settings now. I wasnt sure if it was worth the effort to re-wire the board. I am kind of a stickler for details; but did not want to go screwing something up and causing more problems. I was looking for opinions on re-wiring. If there is no need to re-wire it, then it will probably not get re-wired cause when it is running, I probably wont want to screw with things and mess something up.

[Six_Shooter]

How do you have the bypass wire connected from the HEI ICM (Ignition Control Module)? You don't have D16 controlling like your MSQ would suggest.

FWIW, D14 is an output that is what tells the ICM when to trigger the coil, not an input, just want to make sure that's clear.

I'm not sure J10 is capable of directly triggering the ICM, it may be, but I've never done this personally. I like to have a buffer in the circuit in case anything happens that might cause a problem with an output. Cheaper to replace a transistor than a whole MS2 daughter card. JS10 may be able to drive the ICM directly and if it is, then what you have will work, but I'd use D14 if it were my ECU.

[ironwill11]

It is difficult to keep the engine running long enough to check timing because the injectors do not inject any fuel above the cranking threshold.

This may have been covered before. Are you sure these are low-impedance injectors? Have you tested the injectors using the test-mode?

Your "whiteout" datalog shows a normal injector pulsewidth. If there's no fuel coming out, it makes me wonder if they really are low impedance injectors or whether your injector parameters are set correctly.
High impedance injectors should have "PWM current limiting" set to "Off".
If these really are low impedence, try increasing the PWM Time Threshold to say 1.5ms and the PWM Current Limit to 75%.

James

All GM TBI injectors are low-Z.

But I agree, using the test modes is a huge help in diagnostics.

I just compared my settings to the OP's...

My current limiting setting is at 75%, with a PWM time threshold of 25.6 ms... where as the OP's is 30% and 1.0 ms respectively. There will likely be some issue here.

Hello,

I tried changing my current limit to 75% and time threshold to 1.6ms and got pretty good results. I was going to try 25.6ms like you suggested but it seemed a bit high and I am not that knowledgable with the consequences of this stuff yet.

2016-10-25_23.16.43_P&H_75_1.6.msq

2016-10-25_20.04.37_P&H_75_1.5.msl

It took a couple of tries to get it to keep running but it would idle at a respectable rpm, 800-900. Not sure if I should make further adjustments to these settings or not. It seems like you did a lot of adjusting to your time threshold.

Will

[Six_Shooter]

I did no adjusting to these settings, just original settings that work well...

[ironwill11]

I can now get the engine to start and run, keeping the throttle open to keep the RPMs to get past the cold period. Once it is warmed up it fires right up and idles (~850, a little high). I have my timing light on it now; and I appreciate the information about the trigger wizard. While it is idling the larger number in the black box at the top entitled "Advance (degrees)" says 11.0 and the "ignition offset angle (deg)" has input of 10.0. While Idling I have the timing light on the dampener which is reading right on 0 degrees TDC. I appreciate all the info about the trigger wizard but I am not quite sure why these numbers don't seem to line up.

Here is a video showing 0 degrees TDC and the trigger wizard:
https://www.youtube.com/watch?v=-xqy5uXx7do

This is a video of me adjusting the "ignition offset angle" down and then showing the timing getting more advanced:
https://www.youtube.com/watch?v=gR9CZlnMR2Q

From my understanding it seems like I should use a the dial back timing light to adjust the distributor so that way when the "ignition offset angle" is 10.0 and the "advance" box in black at the top says 11.0, I should change the timing on the dampener from 0 to 11.0 degrees advance to match the timing light reading to the back box entitled "Advance". Does this seem correct to anyone?

I am using MS2 V3.0 firmware 3.4 with GM 8 pin HEI control module.

I did get my wideband O2 replacement up and running which was reading lean the whole time (16-18 AFR). I read in a few spots that TBIs like to idle slightly rich. I was going by the gauge mounted in the truck since it was simple to see.

2016-11-04_17.37.05_At_temp.msl

2016-11-05_00.35.31_trigger_settings.msq

Thanks Will