VEMS Community Forum
Technical => Triggering => Topic started by: Agriv8 on March 09, 2007, 09:19:19 am
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So I plan to get my Wasted spark up and running this eve / over the weekend.
I have a 36 -1 primary trigger installed on my crank so a tooth and a hole = 10 deg ( 5 deg each ) this will be firing 4 wasted spark coils
So I belive need to work out the deg between the missing tooth and the TDC and enter this into megatune.
My question is this am I working out
the degrees between TDC and where the Start of the missing tooth would be
Or
the degrees between TDC and where the center of the missing tooth would be
Or
am I barking up the wrong tree all together
Is there anything else I need to be made aware of ?
Many thanks
Agriv8
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The way I did this was to mark TDC on the harmonic damper on the crank so that I could use a timing lamp on it when cranking with no plugs in the engine. I adjsuted the timing of the spark to 0 in VEMS (crank ignition advance setting in Megatune) so that I got a timing pulse that should show the crank pulley mark lining up with the needle on the timing cover.
Obviously you need to come up with a best guess to start off with, so work everything out using the leading edge of each tooth. Note that you aren't triggering on just the missing tooth, you can trigger on any tooth, as long as you reference it to the missing one.
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Yep that makes sense and it worked spot on.
So how do I work out which pin goes to which waisted coil pack. I have 4 spark coil packs so for trigger wires. accourding to my instructions pins 33 to 36 are my coil drivers.
Regards
Agriv8
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You define the coil pattern in software, so you can plug them into which ever hole you like.
I prefer to match them upto their software equivalents: Coil 0->EC36-pin35, Coil 1->EC36-pin33, Coil 2->EC36pin34, Coil 3->EC36-pin36
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Thanks Rob that makes sense was going to have a look last night but was spannering a RGB racer yesterday , will check those when I get chance.
Where in the software do I define the coil patten.
Many thanks
Regards
Agriv8
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It's easy through MegaTune
Settings->Ignition Outputs
The drop down boxes define the pattern, remember that it counts from the highest numbered cell down to zero.
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Struggling with this all evening either I have my trigger settings out ( but have checked with timing gun )
so the basic in pictures
My Ignition settings are as so
(http://i167.photobucket.com/albums/u157/Agriv8/ignoutouts.jpg)
and how I have them conected
(http://i167.photobucket.com/albums/u157/Agriv8/igntablecon.jpg)
getting sparks just not at the right time help required before the next dor neigbour slaps an asbo on me.
Regards
Agriv8
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If you've wired them in firing order (which it seems that you have) then you should have them set
0 = 3
1 = 2
2 = 1
3 = 0
And set yout Ignition outputs in use h[2] to 03..00
Write up your firing order on a piece of paper, and write down where each one is firing in reality so you can figure out whats actually happening.
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Have you definitely got the secondary trigger turned off? This caught me out once and I only got half as many sparks as I was expecting...
Can you post up the trigger settings too? I know you've checked them but you could be running up against some weird software feature when you start to apply proper spark advance.
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Should be the same firing order as mine. It looks right from memory, and they will run on 5 cylinders...
1-8-4-3-6-5-7-2.
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You've wired them in firing order, not in cylinder number order, so Rob's right - swap over 2 & 3 in your sequence.
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So setting the h[2] to 03..00 will give me 4 ign outputs ( 0 to 4 inc ) rather than 8 ( 0 to 8 Inc ).
Ahh ( light bulb on - possibly should that be spark plug spark possibly ;D)
wasted spark -- Looking at it from a piston point of veiw -- rather than crank rotating and angles of the V and crank angles ect ..... ( makes my head hurt ).
2 spark plugs paired together on one coil pack - triggerd by the Vems.
1 of the pair will be on Compresion stoke ( piston 1 ) the other will be on exhaust stroke ( piston 6 )
A FULL crank rotation later the pistons have swapped and piston 1 is on the exhaust stroke and 6 on the compresion stroke.
SO Vems fires the controlling coil pack does not need to know which spark plug is igniting the fuel or which is sparking the 'Wasted' ignighting exhaust gasses.
SO IGN outputs will look like somthing like.
(http://i167.photobucket.com/albums/u157/Agriv8/newammendIGN.jpg)
Hang on Just so I can sus this
The point at which the Coil pack ( ign outputs 00 to 03 ) fires is -- missing tooth +n Deg. So where is n defined as I need to check that as well Dont I ?
need to check secondry trigger disabled and post up my trigger settings when I get home .
I have started drawing V's and cranks again ( off back to the dark server room ) ??? ???
Regards
Agriv8
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The trigger tooth is defined in Settings->Primary Trigger Settings, in an ideal world you'd chose a tooth thats 90 to 60deg BTDC and trim the exact amount using TDC after the trigger (deg)
Remember to set your cranking advance in Settings->Primary Trigger Settings to 10deg TDC, then when you crank the engine you set the ignition to 10deg by the TDC after the trigger (deg)
Its not a bad idea to pull your plugs to put less load on your starter motor, and to have a good fresh battery on hand... Oh and make sure that the fuel injector's fuse is out
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right here is my trigger table.
(http://i167.photobucket.com/albums/u157/Agriv8/primarytriggersettings.jpg)
the timming after TDC was set using dnb's gun method runing of original dizzie and gun fired of Coil pack 0
Gone back to basics tonight and checked out my wiring and switching ( some 12v Leds from malpin )
Need to check with timing gun tommorow.
Regards agriv8
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Get right back to basics and get one coil firing (cylinder one & six for example) correctly. Then add coils one at a time. Turn off your other coils by setting their outputs to an unconnected pin e.g.
0 = 4
1 = 4
2 = 4
3 = 0
Once you have that sorted, its a case of getting the coils on cylinder one to fire correctly, then adding the next pair and so on.
Its worth noting that wasted spark can upset timing lights that have 'clever' advance offset.
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thanks Rob,
Hatched a plan on the train this morning.
the 4 12v LED's ( got them flashing in order last night connected to pins 33 through 36 ) so all I need to do is to tie that up with the engine.
The plan is place the 4 led's in the flashing order around the existing distributor without the cap on ( still timed in OK ) the plan as the rotor arm points at it we got to make it flash !!!
Regards
Agriv8
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Howdy,
Bob gone back to basics as sugested and I think I have been a right royal numpty and got the trigger miles out.
a picture of my setup
(http://i167.photobucket.com/albums/u157/Agriv8/mytrigger.jpg)
Reading through the documentation I have set this up all wrong
I have this bolted though the 3 crank pully bolts so can adjust the trigger in 120 deg incremets. My brain has gone soft agin can anyone pont mt in the right direction
thanks
Agriv8
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So the missing tooth passes the sensor 90deg ATDC?
That means that the missing tooth passes the sensor 90deg BBDC.
So unless you're on an odd-fire engine this will mean that the trigger will be 90deg BTDC of one of the other cylinders.
What you need to do is work out which cylinder is on its compression stroke when the slot is level with the sensor, and use that cylinder as the first in the sequence. Just because your engine has (for example) a firing order 1, 3, 4, 2 it doesnt mean that you have to setup your VEMS in that way, you may be 180deg out so you'd have the sequence 3, 4, 2, 1
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So the missing tooth passes the sensor 90deg ATDC?
That means that the missing tooth passes the sensor 90deg BBDC.
So unless you're on an odd-fire engine this will mean that the trigger will be 90deg BTDC of one of the other cylinders.
What you need to do is work out which cylinder is on its compression stroke when the slot is level with the sensor, and use that cylinder as the first in the sequence. Just because your engine has (for example) a firing order 1, 3, 4, 2 it doesnt mean that you have to setup your VEMS in that way, you may be 180deg out so you'd have the sequence 3, 4, 2, 1
So the missing tooth passes the sensor 90deg ATDC?
>>>>> the missing tooth will pass the sensor about 50 deg ATDC
That means that the missing tooth passes the sensor 90deg BBDC.
>>>>> BBDC Whats that ?
but I need to set my 'TDC after trigger (deg)' my TDC after trigger is 310 deg it wont let me set it above 170
For referance my Priamary trigger setting are displayed on the other page.
Thanks
Agriv8
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BBDC = before bottom dead centre.
Don't worry that you can't set 'TDC after trigger' to be correct for cylinder 1 - use a different cylinder as your TDC reference and VEMS won't care provided you change your fuelling appropriately. (With batch fire it probably doesn't matter anyway)
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Ok so I can use which ever out of the 8 is coming up to TDC on compresion stroke when the missing tooth is lined up with the Sensor.
This is going to get me close but how do I tell the VEMS to wait that last few degress until the piston is at TDC and therfore fire the coresponding coil pack conected spark plug.
Regards
Agriv8
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Don't forget that the missing tooth doesn't have to be the trigger tooth!
The missing tooth is numbered 0. The first tooth is 1, second is 2 etc... So set the "trigger tooth" to be say 6 (leave "next trigger tooth" set to 9 (IIRC) as this is an offset from the first trigger tooth) to move around the trigger point. You then need to set up the 'TDC after trigger' to suit tooth number 6. Therefore it really doesn't matter where the missing tooth is - VEMS doesn't really care as it only uses it as a reference point.
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Ahhh light bulb may be flickering on.
So the missing tooth is the referance for the vems.
that tells the vems to start counting teeth when it gets to the tooth I have nominated the Tiger we get a spark.
from that point on we get a spark every 90 deg that the crank - equating to 8 sparks over the 720 degrees.
all I need to do is to tell the vems which coil pack I need to fire at each 90 degrees ( in other words the order ).
As its wasted spark we can set the sequence of the 4 coils to repeat every 360 degrees.
Clear as mud that ( i hope ) .
Will try and draw that up as a picture I work better in picturs and may assist in other installers like me who somtimes stuggle to digest the instructions correctly.
regards
Agriv8
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That sounds like the way I understand it working. At the very least we're now both working under the same misunderstanding ;)
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Oh bu66er not sure how but I have lost ign driver on pin 36.
looking throught robs pages there may be some other ones but how can i work out which if any are 12v drivers that I can use for my wasted spark.
Assuming i have blown a fet next time I have the vems apart i will solder a fresh on in will contact rob on monday and see if I can buy one.
regards agriv8
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It all depends on which option you had when you got the system:
Option 0 All 8 injection channels have logic level(+5v) control for coils that have built in igniters or systems where you wish to use an existing Igniter pack:
(http://www.vems.co.uk/VEMSUserManual/CoilOptions/IgnitionOption0.png)
Option 2+6 Two channels are high current, the other 6 are logic level:
(http://www.vems.co.uk/VEMSUserManual/CoilOptions/IgnitionOption2+6.png)
Option 4+4 Four high current channels, Four logic level:
(http://www.vems.co.uk/VEMSUserManual/CoilOptions/IgnitionOption4+4.png)
Option 6+2 Six high current channels, two logic level:
(http://www.vems.co.uk/VEMSUserManual/CoilOptions/IgnitionOption6+2.png)
Option 8 All 8 channels are high current control channels:
(http://www.vems.co.uk/VEMSUserManual/CoilOptions/IgnitionOption8.png)
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thanks rob,
got that printed in the garage but as I bought the unit second hand I dont seem to have any indication of which optoin has been chosen guess its just a case of finding a live one by sawpping the pins over.
regards
Agriv8
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I'd pop the case open and trace through which IGBTs are populated.
Chances are I'd pop the dead one out and move one of the good spares in its place.
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So are the 5v logic drive IGBTs the same as the 12v one ?
If not how do I identify 12v IGBTs ?
Looking at the pictures it again pin 10 is a favorite if its populated.
regards
Agriv8
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The logic drive is provided by a wire jumper on the board, it doesnt have an IGBT connected and is current limited so not much danger of popping things with it.
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in that case I think I have a few to go at.
(http://i167.photobucket.com/albums/u157/Agriv8/vemsboard.jpg)
Have tea and will go and investigate and report back
Regards
Agriv8
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You have four IGBTs there, they're the ones with the insulation stuff stuck on the back.
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thanks Rob.
I will ring you tomorow to get some spares sent through ( whats the best time and number to contact you on ) do you stock them ? - if not can you suply information so I can source one from RS likley ( as I have just found that my good frind marc has a trade account :) ) or Maplin local to me at work but may not stock them :(
but from looking at the track map seems i have
8 for the injetors ( only using 2 at the moment ) cant use these are they are different.
2 for the WBO'2 sensors only using 1 these run to the econoseal 18 ( not selectable for ign output under megasquirt ) not good enough at the command line yet :D
4 for the coils ( 1 of which I have killed )
I suppose I could swap the spare WBO one over, but if i am going to operate it makes sense to me to replace the one I have killed and fit another couple of spares.
Two reasons
one I have still not identified what has blown the original so could do it again leaving me with no resiliance.
two my soldering is not the best and don't want to chance lifting a track when moving somthing thats not borken just for testing
So as I see it going to get 3
one to replace the duff one connected to pin 36
and 2 spares to fit in the non populated ones easilly usable in case of further issues
TTFN
Agriv8
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Right,
Must be doing somthing wrong here. replaced the blown ign driver and added 3 New ones,
Cant get ant of the 3 I have added or the one that I have replaced to do anything.
Checked the invoice and I have definatly got Ignition drivers is there more than one sort ?.
So
Do i need to do anything after adding the 3 NEW ign drivers running. They are selectable in Megatune but not getting anything out of them. when connecting the to a coil.
Or
Have i really done somthing serious and blown part of the board If I have can ROB got the facilities to test ?
Regards
Agriv8
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If you have metal backed power transistors then you have the drivers.
Can you send me the MSQ you're using please?
If worst comes to worst I have a test bench to debug.
Rob
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Rob MSQ sent.
Kind regards
Agriv8
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Received, just having a look and will respond via email.
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Just a quick post up while hopefully having a celibrtory cuppa ( or in other words its too early for a beer to celibrate)
a few thing i have just learnt - listed in order of importance.
1, Rover 45 deg plug leads are a barsteward to get on correctly as they are very tight and even when you think you have them connected correcly they may not Be !!!!! The engine is running of dizzie and a spare set of plugs all nicly earthed in the vally of the V It looks like I have sparks on all 8 plugs ;D ;D so all I can assume is that I have not been getting the leads seated properly.
2 As Rob pointed out earlier waisted spark coil parks do funny things with timming guns - both my timming guns are playing silly beggers while trying to do the base timming :( :( :(
So back to it.
TTFN
Fingers crossed and Ill report back later Agriv8