TOYOTA Celica GT-four
24 tooth VR trigger and 1 teeth VR cam sync trigger. Want to drive wasted spark with the BOSCH coil from webshop.
When cam sync trigger is by its sensor, than the engine is 30 degrees before top death point cyl. 1.
VEMS Firmware 1.1.17beta
My question is, which values I have to set on the following tables.
I have tried to find out some documentation to gat the answers by myself for uncountable hours
So please explain me the tables below.
• TDC after trigger is it right, when i fill in 30 ?
• Number of theeth on wheel my wheel has 24 tooth, so i type 24 ?
• Tirgger tooth what is this ? is this the first teeth after the trigger of the second wheel,…
• Next trigger tooth what is this ? means this that all 6 tooth from the trigger 1 is an ignition event ?
• Crank min. period what is this ?
• Tooth Normal Relative min% ???????
• Tooth Normal Relative max% ????????
• Tooth Missing Relative min% ???????
• Tooth Missing Relative max% ??????????
Secondary Trigger :
• TODO! Should be 0x02 when disabled! ????????
• Use I have to choose „cam sync“ ????
• Rising edge is this in degrees and is this the position, where the first trigger wheel is ?
• Falling edge what does this maen
• Angular width of tooth ???????
• Angular width of missing tooth I have no missing tooth,…. ???
• Engine phase, when to reset ???????
is anyone out there who can explain me the trigger settings ?
Now I tried some different values, but i can't get any rpm readings on the display when I drive thr sensor with a drilling machine. I only get the value of approx 500 rpm with different tooth values.
My firmware is 1.1.27beta,
is it possible that this is the wrong firmware ?
1.1.18 is what I've had plenty of 24+1 systems working with, try that or go for one of the new 1.1.6x firmwares
Thank's Rob, now I changed firmware to 1.1.18 and set the values al follows
(http://www.vems.hu/files/ThomasSchragl/primary%20trigger%20setting.jpg)
(http://www.vems.hu/files/ThomasSchragl/secondary%20trigger%20setting.jpg)
I drive the sensors with a drilling machine and the rpm reading is max. 500rpm.
What I have to chsnge, that it could work.
I think the right rpm must be around 3000rpm, because the drilling machine makes 1500rpm.
Cool - its looking promising.
Lets turn off the secondary trigger first and get a stable reading from the main trigger.
I'd set the Number of teeth to 12 - remember that this is distributor mounted trigger and runs at half engine speed, the ECU will count 12 teeth and then count that as one revolution which will be correct.
now I changed the primary number of teeth to 12, and nothing happened,
the rpm reading was allways the half of the drilling machine.
When I chande the "next trigger tooth" from 6 to 3, then I can read the
rpm of the drilling machine. But I need to read drilling macjne x2.
here is an oszi picture from the trigger signals after the LM1815 (straight to the µP)
(http://www.vems.hu/files/ThomasSchragl/TEK00025.jpg)
I hope there is no error ?
ok now I think it works.
whats about the "constant for rpm calc." this value was 750 and now I set them
to 3000. -> and It works !!!
The number of tooth on wheel is now 24.
Only one question, have I set the trigger tooth 0 and next to 6 or other values ?
You can set trigger tooth to which ever tooth will give you a TDC after trigger of 60 to 90 deg. The next trigger will always be 6 - as this number is relative to the trigger tooth.
Your scope trace needs to show the output from both of the LM1815 chips so that you can ensure that 24 pulses are delivered to the AVR from the primary to a single secondary pulse.
The green one is the secondary trigger, the measuring bars of the scope stands on the teeth of the trigger.
When the sec trigger comes, the position of the crank is 40 before TDC of cyl. 1,
is it ok, when i set first trigger to "3" (which is 70deg. after TDC) and next to "9".
:-[ Yes - I can see the TWO traces now you've pointed them out :-[
The second trigger is relative to the first, as you have 6 teeth between each cylinder thats the value you go for, moving the primary tooth will always end up moving the second, so when you set first trigger to 3 and the next to 6 it will trigger on tooth 3 and 9 (6+3) then 15 and finally 21.
More complicated tooth arrangements are defined in the h[1] table, but we'll worry about them later.
Thanks for your help,
the next plan I have, is to hook them up in the car, to make the first start up.
reguards Thomas
Yesterday I started to fire up the engine,
nothing comes out of the engine !!!
We saw ignition looks like it will be within the timing
but i cant check how often it fires,
on cyl.1 i checked, if the injection fires, also ok.
result ... nothing
whats wrong ???
Have you done a visual inspection of the plugs? Make sure the body of the plugs are earthed and the tops connected to the distributor and check that each one is getting a spark.
Then its time for the timing light - check each one is firing and notionally in the right place.
I checked all plugs,
yesterday my first step was to check the timing with
timing light, and i set them 10 deg before tdc cyl1.
at the next i connected the injectors,
then i want to start.
after some start up test with no result, i checked the ignition
timing again, i saw only one ignition event and then nothing.
I charge the battery and try again.
I saw more ing events and then nothing.
I connect a lamp on injector plug 1 and saw them flashing.
I check the plug from cyl 1 and it is dry no fuel ????
Could it be, that the battery has to low voltage to start the engine???
What are your cranking PWs?
Is the fuel pump running?
Always have a spare battery when starting for the first time!
Bascs:
Kill power to injectors
Kill power to spark plugs
Swing engine
Does fuel pump start?
If not then you need to setup triggers better, or fuel pump setup/hardware!
fuel pump is running
all other values are ok, on the MT screen
i saw a injetion tiime of 6ms while cranking
It depends on the size of the injectors - but that seems a little on the low side, my rule of thumb for cranking PW is
3 x Req_fuel for the cold crank
0.75 x Req_fuel for warm crank
Ok,
in which table i must correct the value ?
Here is a graph from my trigger wheel and some commends,
please have a look at them and give me your ok if this is right.
(http://www.vems.hu/files/ThomasSchragl/wheel_doku.jpg)
My injectors are 450ml and enigne displacement is 2000cc 4cyl. -> means reguest of fuel 6ms
Yesterday i tried to start again.
Now when cranking i had 16ms of injaction pulse an the plugs are always dry.
They smell only a little bit of fuel.
Ignitoin looks good, and when the voltage of the battery goes down,
the ignition is away, i set the coil dwell time from 3.3ms to around 6, and the ignition is
here again.
Engine does not run !!!!!!!!!!!!!!!!!!
So you have quite a voltage drop.
Have you moved the
You need to start data-logging your start attempts so that you can review the transient changes and tune the settings accordingly.
but an original ecu starts the engine,
when the starter motor is able to turn the engine
for only a few strokes before the battery is empty.
An there the voltage is very low and the injectors fire.
In my case i measured the voltage supply of the injectors
from 9V while cranking.
please have a look on my config, i hope the settings are ok,
because i tried to start the engine for about 10 hours and nothing
happend.
http://www.vems.hu/files/ThomasSchragl/config.txt (http://www.vems.hu/files/ThomasSchragl/config.txt)
My starter motor is suffering.
The original ECU will have the correct injector battery factor, and will have had many man hours of cranking fuelling.
Don't cook your starter motor - if the car is not starting within a few seconds then there is no need to keep cranking.
If your battery is loosing voltage then you need to sort that problem out, constant cranking will damage the thing.
Looking at your config...
battfac seems low - only 9 - the higher the number the more the ecu will hold the injectors open as voltage drops.
All other values in my config looks realistic ?
Value "battfac (us)" - what is a good starting point
Ok,
yesterday evening i tried some other values in batfac from 600 up to 4000,
the next i tried was to set the prime pulse to 20ms.
When i turn on the unit it squirts 20ms, i turn on and of the unit for 5 times without cranking,
then cranking and it comes a big bang from the exhaust but no more. Plugs are dry !!!!!
Also i soldered some leds to the injection cables, when i turn on the unit all 4 flashes,
and when cranking also leds flashing. but i get not enough fuel!!!!!!!!!!
no firing, ignition point looks good.
I don't know what to do next
can you scope the injectors to check that they're actually pulsing?
Normally I set prime pulse to zero and increase the cranking PWs, and normally I have a problem with wet plugs rather than dry.
There seems to be something strange with the fuel delivery, if you can monitor the pulses with a scope or at the very least a light then you will be able to ensure that the injectors are being driven correctly.
Today, i give it the next chance to start.
The leds, which i had soldered, are paralell to the injectors.
And they will flashing when we crank.
Now i check the pulses via scope, to see how long the voltage is applied.
Are there some factors in the config, which i can change to get longer
injector pulse time while cranking ?
Is it better to set the "cranking threshold" to a higher value e.g. 800rpm?
In Settings->Priming Cranking Afterstart you'll find cold and warm PW values they're just before the cranking threshold, you can set the cranking threshold higher, but at the moment its not the cause of the problem as you're not going to be getting more than a few hundred RPM.
I drew up this event timeline to describe the stages of getting the engine running:
(http://www.vems.co.uk/VEMSUserManual/PrimingCrankingAfterstart.png)
ok thanks a lot,
i check all settings again and record the
injector signals afternoon.
And get yourself some datalogs so that you can review what was happening after the cranking tests.
Rob
Surprise !!!
car is running, very rough, but it's running.
The main thing what i changed was the crank
threshold rpm from 300 to 800.
Now the next challenge are wet Plugs
Battery is empty again.
Is anyone out, who knows the right dwell time for
the bosch ignition coil packs from the webshop ?
the next start is tomorow morning.
Mate, there is a link on the webshop page to the coils:
http://www.bosch-motorsport.com/pdf/components/ignition_coils/2x2.pdf
It gives all the info you need.
Yes i know,
but i set the dwell time to 3.3ms and the
max value for 6V 6.88, wich seems to be to low
for ignition.
With full battery, the value is ok.
But when the supply voltage of the coil goes down to 9V,
there is no igniton anymore.
At 9 Volts nothing really works ok. Your battery or your connections to the battery or between ground (engine to chassis even) are clearly not very good. If you do a datalog (ALWAYS DATALOG, hard drive space is cheap) and check it out you can probably see that the ECU may reset during this time, look for any inconsistencies in rpm, voltage, etc..
Also, don't start your engine running flooding wet super rich. It's not a problem if you start lean, it's only idle with no load. Your rod bearings and cylinder bores will thank you for not washing it down with fuel and wasting oil.
If your req-fuel was calculated correctly (let's assume) then you just lower the VE values of the cells in the whole region around idle by a lot.. if it's super rich but runs, you could probably cut 30-40% to get near the true value. Do make sure your lambda target table is ok before you make any changes.. it's a part of the fuel calculation.
From what I have seen,
idle region is almost always 40-55 if the req fuel is calculated correctly and map multiplication is enabled.
Update:
engine is not running,
here is a log of my last tests.
http://www.vems.hu/files/ThomasSchragl/datalog201002102146.xls (http://www.vems.hu/files/ThomasSchragl/datalog201002102146.xls)
it seems to me, that i am far away from a running engine,
the first event is in April, but there are so much trouble
to get the "Testcar" running.
If you can run the car on the standard ECU and you have a scope, then you should be able to find out the cranking and idle pulse widths.
Make sure that you are not firing all banks when cranking - somehow you have gone from no fuel to too much fuel and a ~11ms cranking pulse shouldn't be causing this.
Hy,
some good news from me, but one question:
The main error was, in one engine cycle (720 degrees) i had only two ignition events.
So i checked the "reference tooth table" and set the values 22,16,10,4.
now i had the right ignition and the engine is running.
but when i check the ignition timing with the timing light, i saw that the timing always
jumps around.
I measured at 1500rpm.
On MT the value is about 9 degrees, on the engine i saw its jumping around 10 degrees +/- 2degrees.
But i in recurring steps, the timing jumps to 30degrees for one spark and then back to 10 degrees ???
You can hear this bad ignition from the engine its not my timing light.
Whats the problem ???
attched is a log from last test.
http://www.vems.hu/files/ThomasSchragl/datalog201002160401.xls (http://www.vems.hu/files/ThomasSchragl/datalog201002160401.xls)
Can you scope the trigger with the engine running?
Are you having any trigger errors, 30 deg change sounds like a missed tooth.
You're going to have to start looking at experiments with pull-up and pull-down resistors.
I never had any luck with a Toyota trigger, sure it worked on my drill, but a running engine is a completely different matter.
Thanks Rob,
i will check the trigger signals with the scope tormorrow evening.
I wired the trigger signal in two seperate cables with shieldings to the controller,
and MT tells me no trigger errors.
When i have trigger errors, can i see them in the log file ?
The problem i have is, i will install the vems in my rallye car,
and so i must come in common with the original trigger.
Because my homologation sheet gives me the hardware,
which i have to use.
Okay, so you will need to do some extra precautionary work then, you may be wise to make yourself something like those earthing kits that the tuner boutiques sell, pulling all the grounds to a central grounding point may help with cutting down noise.
Is it possible to check on megatune, when vems has a missing tooth ?
Or can i see this in the log file, or on a gauge on the megatune screen ?
a missed tooth would show up in megatune as a trigger error, and in the data log there would be either a red line or an erratic RPM reading.
I am assuming of course that you have none of the idle control functions active - spark scatter and idle advance control would cause erratic timing.
Now I measured the pulses,
the trigger pulses looks not bad,
but what is with the ignition pulse.
light blue is trigger 24 tooth
dark blue is cam trigger
purple and green are the pulses to the wasted spark coil
(http://www.vems.hu/files/ThomasSchragl/TEK00000.jpg)
the cars runs I think on three cylinder and megatune tells me "missfire"
what do you think about this behavior
Very informative traces. I am assuming the purple Ch3 and green Ch4 ignition traces were done with the scope probes GND on +12V and the probe tips on the coil primaries (pins 1 and 3 of the Bosch 2x2 coil).
Seems like your dwell is now at 10 ms, as shown by the troughs of Ch3 and Ch4. Also, it is strange that the other coil is building up voltage (down ramp of trace) while the other coil is on the dwell period. I'm not familiar with the characteristics of Bosch 2x2 coil but that is strange behavior to me. Cross inductance, or failed insulation?
(http://www.vems.hu/files/ThomasSchragl/TEK00000.jpg)
No, the ground pins from the oszi is on ground.
Yes, the dwell time varies allways,
in my setting i have the value 3ms at 14V.
Now i am in the labor again with the drilling machine,
and instead of the coil i connect two relais.
Same behavior, plus ??misfire??.
When i change the ingition outputs to other, which are not connected,
then i have no ??misfire??.
Theres often an issue with misfire showing - ignore it for the time being, its the trigger error you
Can you identify which are the three running cylinders? You should test each cylinder with a timing light and ensure that the pairs of cylinders are correctly firing at TDC and BDC.
Running on 3 cylinders could be down to injectors as well as ignition.
You trace looks fairly solid from what I can see - I am a bit concerned with the dips in the cam trigger - the LM1815 chip senses voltage crossing zero, that might be a source of mis-triggering.
Its also worth taking a look at:
http://www.vems.hu/wiki/index.php?page=InputTrigger/TriggerLog
I have also passed this thread to the dev team, one of whom said:
"reference tooth table" (h1) values 22,16,10,4 look strange. They could (and should) work, but standard practice is to set 18,12,6,0 (or rather 0,18,12,6 for quicker startup), and trigger_tooth=04
More comments:
"VR campulse is ALWAYS problematic. That with the dips seems to require strong pullup (10k could be tried, but resistance and DC bias measurements needed). A thematical page would ne nice."
"look at the 30+% coil supply voltage drop when the OTHER coil dwells. Clearly the coil supply should be checked, possibly redone"
Good morning,
thanks for the hints,
what for me is confused too, is the dwell time or the
ignition coil, in Megatune i set them to 3.3ms, but in the scope i see ~10ms.
The dip on the cam trigger is the "little mountain" 180 degrees apart of the trigger tooth.
Is it better, when i remove them with a grinder ?
I disassambled the unit and measure the outputs of the two LM1815,
and there are no problems with the dip, but my drilling machine turns only 3000rpm.
I think you're going to be having issues with a ground down sensor too.
The suggestion for a pull-up is to ensure that the bias voltage is high enough that the dip never crosses zero. The voltage from the main tooth is large enough to pull a fairly significant bias voltage below zero and therefore trigger the LM1815.
Best to worry about getting the crank signal clean and reliable and to check the power connection (2mm dia core) to the coils, before getting concerned about the dwell time, dwell is ramped due to voltage and a number of other issues.
Another scope
make with drilling machine,
light blue is cam sync (with 10k pullup)
blue is cam sync after lm1815 straight to µP
purple and green ignition coils (relais)
h1 table 18,12,6,0
ignition looks good, but in depend of the dwell time, the ignition point varies all the time.
When you meter the scope trace, you can see that the ignition events are not 180 degrees apart.
(sometimes yes, sometimes no)
(http://www.vems.hu/files/ThomasSchragl/TEK00002.jpg)
Yep - that's not an even spacing on the ignition events.
Lets nail the blue trace first - how much above 0v does the small dip drop to?
If its well clear of 0v we can stop looking at it and start concentrating on the 24 tooth trigger.
Can you scope the 24 tooth trigger now with its lm1815 trace and the relay coils?
We can then check that the thing is triggering off the correct tooth and if there are any anomalies in that signal.
Here are the scope files,
for better reading i measured purple and green on the
gate of the ITGB's.
20 degrees spark advanced.
(http://www.vems.hu/files/ThomasSchragl/TEK00003.jpg)
(http://www.vems.hu/files/ThomasSchragl/TEK00005.jpg)
Is that quantization thats causing the thicker light blue lines?
I cant see clearly but they dont look even.
Which would result in an uneven trigger and erratic timing.
You would do well to capture the 24 tooth VR signal along with the output from its LM1815
Then you should be able to see what is causing the uneven spacing.
No this what you tell quantization what you mean, is only the oszi resolution.
The light blue pulses are exact 24 pulses between one trigger, with exact 100µs.
Measured after LM1815, straight to µP.
But if you want, then i make a new picture with better resolution, but then you can't see
one engine cycle.
We're not going to be able to see the 24 tooth trace with the right clarity here, so you need to be able to look at the traces and see if you can see where the LM1815 trigger occurs out of sync and if theres a corresponding signal on the VR input.
The 24 tooth trigger is not going out of sync.
The pulse frome the LM1815 comes allways at zero crossing of the vr sensor.
Allways 24 in one cam pulse.
For me the dwell time is the problem.
At the last post, i set them to 1ms and 0 at 6V,
but on the oszi the pulse is 4ms and variables.
The beginning of the ignition pulse is allways perfect 180 degrees, but the variable
dwell makes the ignition inacurate.
is it possible that this is better with another firmware.
Now i have 1.1.18
1.1.18 is running on many cars for a number of years, and we've not seen this problem on them.
The majority of these cars are Nissans running external amplifiers - and therefore inverted outputs, so make sure that you're not running inverted.
I have seen ignition advance change with engine speed with the ignition outputs inverted, but never seen variance between spark events.
I'll make sure that the dev team get to see your last couple of posts.
Is is possible to erase the internal memory of the µP ?
I want to set the unit completly to zero.
Load the firmware 1.1.18 new and make the configs from the start.
When you upload the firmware you'll see that the console reports that its erasing the flash.
To zap the config and tables you can make a tables file containing completely zeros.
If you really suspect the firmware then you might be as well to try one of the newer versions
No i am not thinking, that it comes from the firmware, but i must try something,
because the time to the first event is not very long,
And when the first is running, i have to order and assemble another
two vems plus wiring for our rallye cars.
You might be well placed to put these details on the Wiki - once its there I can press the developers to put more effort into solving your problem. This forum isnt officially supported so its just down to us users to help each other out here, you've identified something outside of the scope I've ever seen before.
My "testcar" is now running.
I changed firmware to 1.0.73 and remove every 12 tooth.
Now I am running 12-1 with no camsync, wasted spark and injectors are all fires at same time.
I checked dwell time with the oszi, and it works correct.
The car runs without any trigger errors.
If you have a missing tooth then you can run sequential injection, it will be nicer.
Good to hear that it is working, I think with more time and filtering of the cam sync, you should be able to get a working signal.
If you are sticking with v1.0 then I would suggest that you use 1.0.78.
Using 1.1.6x will give you even more options.
Ok,
i will try the sequential injection.
I use 1.0.73 because you nominate this firmware in an other tread.
You mean, that the problem with 24+1 trigger is the cam sync ?
The signal after the LM1815 was ok,
the only thing what i see, is it possible, that the position between the crank pulses could be the problem ?
Because on your trigger disk, the cam sync allways comes between two crank triggers and in my
case, the trigger comes in the first third between two crank pulses.
Which firmware i have to prefer, when i will stay on this trigger type (12-1) for a race car ?
I want to run, ALS, Lauchcontrol, perhaps water injection.
Yes 1.0.73 is a good one to get an engine running on, but the newest firmware would be worth testing, you may have noticed that people are using it with VEMSTune and getting some positive results.
I say that it must be the cam sync because now that you have removed it the triggers work, but I guess that this may not be entirely the case. Eitherway you have a trigger that appears to work now.