No Spark During Cranking

[kseven]

Hey guys!

I am working on transitioning my ECU from an alpha-n based ECU (PE3) to the MoteC M1 series. For reference, we run a Yamaha R6 engine with stock coils wired to the IGN4 module, and stock injectors (only primaries), as well as modified intake and exhaust. We have been unable to get the engine started since we switched it to MoteC

So far, we have set up our Ref/Sync and are able to get cycle lock. We also verified that fuel was being injected during cranking.

When we tested the Spark plugs, we felt no spark. This is really confusing because spark works perfectly fine when we use the built in spark test. Also, there are no errors in the ignition output diagnostic and all the channels on the ignition configuration page seem fine during cranking.

We have our cranking ignition angle set to 10 degrees. For our Ignition Coil Charge time main table, we are using a table that I found on the MoteC forum that was posted by a MoteC employee. We are at a loss for what could be causing this issue.

We have also made some small changes to the firmware using M1 Build to replace lambda using LTC, with lambda as a normal analogue voltage sensor. We also were having issues with Engine Charge Temperature Port Delta being around 234524450000000000 degrees Celsius. We ensured that there were no lambda values set to 0 but it remained at a very large number. To fix this, we turned port delta into a parameter so that we could make it a value in its expected range. Besides this, we made sure that none of the fuel or spark related code was modified. We are pretty sure that this is not the issue as fuel is not the problem.

Any help would be greatly appreciated!

[Stephen Dean]

Hi,

In your Package the Engine Run Switch does not have a resource allocated and the Default is set to off. I have changed this in the attached Package, can you load and test this thanks. The Engine Run Switch disables the Coils, Injectors and fuel pump.

With the changes that have been made to the Lambda, if the Engine Charge Temperature Port Delta was that large, with no 0.0 Lambda Aims, then there may be another broken piece of code in your build.

[kseven]

Hey, thanks for your quick response and help! We added a run switch and ignition works fine now. However we still are seeming to have issues getting our engine to start. We have confirmed that fuel and spark work, so that leaves timing.

Even though we get Cycle lock, we checked our ref sync anyway and it looks very strange. We checked with an oscilloscope and it does not match at all with what MoteC is showing. We ran the engine on our old ECU two days ago and everything was fine so we don't think its a wiring issue (we use a swap-able mini harness to go back and forth between ECUs). I will attach a picture of our ref sync voltages, a picture of the oscilloscope, and a correct picture of our ref sync from our old ECU.

No real changes were made to the tune above except we enabled the engine run switch and set it to one of our dashboard switches.

Motec Bad Ref Sync Picture

RefSyncBad_2-27-24.png (500.92 KiB) Viewed 430 times

Correct Ref Sync PE3

Correct Ref Sync PE3.png (78.36 KiB) Viewed 430 times

Ref Sync Oscilloscope

Ref Sync Oscilloscope 2-27-24.jpg (1.22 MiB) Viewed 430 times

[Stephen Dean]

Hi,

Ignore the voltage trace shown in the time graph, it only updates at 50Hz and is no way near fast enough to correctly show the voltage traces. If you want to see what signals the M1 is receiving, use the Online | Capture Inputs functionality in M1 Tune.

With the non starting, if you have Cycle Lock and have verified that you have Fuel Pressure in the rails, that the injectors are opening and that the coils are firing, then it most likely will be a tuning issue. A quick test is to go to the Fuel Volume Trim worksheet and change the Fuel Volume Trim Overall to 25%, this will enrichen the Engine Efficiency table by 25% over the whole table. Try cranking it after doing this and saving it to the ECU and see if it tries to start. If it does sound like it it trying to start, but doesn't quite catch, add another 10% and try again. If the engine catches, let it run for a short period of time to burn off the excess fuel that has been added, then shut it down.

When the engine is shut down, go to the Engine Efficiency table and use Ctrl+A to select the whole table, then press the = key to bring up the Scale/Offset Value window and type 1.35 (if a 35% trim has been added, other wise use the value from your Overall Trim parameter) then enter to apply an overall 35% trim to the whole table. Once you have done this, return to the Fuel Volume Trim worksheet and reset the Trim back to 0.0. When the Engine is running and the Lambda sensor is reporting a value, go to the Engine Efficiency table and start tuning the idle area to keep the engine running whilst it gets up to temp.

[kseven]

Hey thanks for all your help so far. Been awhile since the last post because we had a fuel rail issue which has now been resolved.

Still no start, but we are getting really close. We have reverted back to the original build sent by Motec and the port delta issue is resolved. We also found a few issues with our ref sync set up with rising falling edge being wrong.

With all the fixes, we think the only remaining issue is our reference offset value. We have been trying different things for this value and we finally were able to get small sounds of combustion followed by after-fire out of the exhaust. We hear a loud pop and see flames coming out of the exhaust. This leads us to think that our timing is off.

We have a timing light that we hooked up to the engine on our old ECU so we could look at it with the engine running. We found an advance of 15 degrees on the timing light was needed to line up the TDC mark on the crank wheel to the TDC mark on the crank housing. I'm not sure if this helps us find the reference offset value. We are confused on how we can get the reference offset value and if we need the timing light to do so.

Any help or advice would be appreciated. I will attach a picture of our crank wheel with the mark for TDC cylinder 1 on the left side and the crank position sensor labeled. I will also attach our current tune which is the stock Motec Tune with our own calibrations and an input capture with the ref-sync sensors setup properly.

[Stephen Dean]

Hi,

I have made some fine tuning adjustments to the Reference Mode settings in the attached Package.

To get a idea of the base value for the the Reference Offset, remove the spark plugs from all of the cylinders other than Cylinder 1 and then do another Input Capture. This will result in the engine speed slowing when Cylinder 1 comes on to compression and allows you to calculate an approximate window for the Reference Offset value. You will need to use the timing light to determine the exact value.