Author Topic: Strange ignition output behaviour on bench testing  (Read 5695 times)

Offline msh

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Strange ignition output behaviour on bench testing
« on: October 13, 2017, 09:56:35 am »
Hello.

I don't know if this is the right place to put this thread. I'm about to put VEMS on a stock VW 2E 2.0 8v engine, however, upon bench testing, I've got two strange issues which discourage me from putting loom in car to try to start the engine. When I plug some spare ignition distributor to loom [I'll use stock dizzy hall sender for now] and turn it, either with hands or with drilling machine, two things happens:

1) serial communications becomes unstable - after a few seconds ECU disconnects, then connects again. I've googled and read about changing COM ground to solve that, but that shouldn't be my case, as my COM connection is directly to COM pins on board.
2) second and most important - LED connected between ground and stepper motor channel A, selected ignition output, sometimes flashes, but sometimes blinks, and I'm wondering what does the blinking means. When I turn the dizzy with drilling machine to simulate some constant engine speed, LED varies between blinking and flashing. Once ECU even managed to hang up the measurements - upon stopping turning dizzy, LED kept blinking and VemsTune showed some 450 rpm, and sucking air from MAP sensor didn't changed MAP reading, disconnecting and connecting VemsTune didn't changed anything, but after turning dizzy so that it got few pulses made ECU to exit this state.

Firmware 1.2.38

http://files.inbox.lv/ticket/af237a8739ef61cea8196617331ae42772b8feab/v3.3_u008777-A-2017.10.12-23.17.15.vemscfg

Offline GintsK

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Re: Strange ignition output behaviour on bench testing
« Reply #1 on: October 13, 2017, 03:51:05 pm »
Hi!

2) probably you just mess ecu algorithms with unrealistic RPM changes. Just guess.

Are your Hall sender connected to secondary trigger input?

I suggest firstly solve all errors under config validity check. There are much. And then zero CLT advance table. You have garbage in it. Better start with default firmware config from Vemstune directories.

1) Do you use AC powered drilling machine? Where your ECU is powered?

And please use C004 w/o Camsync trigger settings from drop-down menu under primary settings. 4 ignition outputs all configured to A output.

Does your ECU calibration values matches with factory values from papers?

Gints

Offline msh

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Re: Strange ignition output behaviour on bench testing
« Reply #2 on: October 14, 2017, 09:40:38 am »
Yes, hall sender is connected to secondary trigger input - I had a plan to use homemade rover type 36-1-1-1-1 impulse wheel, but I decided that I can't make it accurate enough, therefore currently primary trigger input is connected nowhere, with free 3 pin connector.

In the config sanity check I just see warning about invalid values in some configuration windows, about features I'm not going to use, and therefore I overlooked them. What do you mean with "zero CLT advance table" - CLT/MAP ignition advance table? It was slightly modified so that config sanity check wouldn't put error about it, but left in a state that it wouldn't affect anything. I put together current configuration with help from a A/S member, who has all around knowledge about ECUs and engine working principles, but not specific VEMS knowledge, he couldn't figure what is that table for, and therefore I left it so that it wouldn't affect anything.

VEMS was powered from car's battery, and serial communication unstability was the same as when dizzy was turned by hand - or when dizzy was turned by hand and connected to my desktop PC and VEMS was powered by powerful PC PSU. Well, MAYBE the instability is caused by USB-serial adaptor - I'll soon try to connect VEMS to my desktop PC, using it's serial port, as it has one, to test that.

Current primary trigger WAS configured with taking C004 NoCamSync and making some adjustments, namely, selecting secondary trigger input and selecting falling edge, as in some help I read that for hall falling edge should be taken. Do you mean that I should select 4 ignition channels and in outputs visual make sure that all are stepper motor A?

Which ECU calibration values makes you ask this question? I ordered my VEMS few years ago as a parts kit, as I couldn't figure out what do I really want, and I put it in 90's BMW bosch DME case with it's Motronic88 connector, with almost everything nicely connected to some pin - so only ECU callibration values I remember to have on papers that came together with board was WBO2 controller values that matched the ones in ECU memory.

Offline GintsK

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Re: Strange ignition output behaviour on bench testing
« Reply #3 on: October 14, 2017, 02:14:55 pm »
Yes, hall sender

OK


Quote
In the config sanity check I just see warning about invalid values in some configuration windows, about features I'm not going to use, and therefore I overlooked them. What do you mean with "zero CLT advance table" - CLT/MAP ignition advance table? It was slightly modified so that config sanity check wouldn't put error about it, but left in a state that it wouldn't affect anything. I put together current configuration with help from a A/S member, who has all around knowledge about ECUs and engine working principles, but not specific VEMS knowledge, he couldn't figure what is that table for, and therefore I left it so that it wouldn't affect anything.
I kindly suggest to clean all errorous settings. Or start with default config.
All cells in CLT/MAP table must be zero. It affect otherwise - corner or border value from table still used.
Quote
VEMS was powered from car's battery, and serial communication unstability was the same as when dizzy was turned by hand - or when dizzy was turned by hand and connected to my desktop PC and VEMS was powered by powerful PC PSU. Well, MAYBE the instability is caused by USB-serial adaptor - I'll soon try to connect VEMS to my desktop PC, using it's serial port, as it has one, to test that.
Possibly adapter, posibly crazy config.
Quote
Current primary trigger WAS configured with taking C004 NoCamSync and making some adjustments, namely, selecting secondary trigger input and selecting falling edge, as in some help I read that for hall falling edge should be taken. Do you mean that I should select 4 ignition channels and in outputs visual make sure that all are stepper motor A?
Yes 4 x A
Quote
Which ECU calibration values makes you ask this question? I ordered my VEMS few years ago as a parts kit, as I couldn't figure out what do I really want, and I put it in 90's BMW bosch DME case with it's Motronic88 connector, with almost everything nicely connected to some pin - so only ECU callibration values I remember to have on papers that came together with board was WBO2 controller values that matched the ones in ECU memory.
104 as zero DC. Just unusual.

Offline msh

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Re: Strange ignition output behaviour on bench testing
« Reply #4 on: October 17, 2017, 04:11:46 pm »
104 as zero DC. Just unusual.

Pump Zero PW? It was 103, then I did 2x100 ohm resistor test, found just 4.0 volts and tried to get 4.1, as written in that tutorial I was reading - 105 gave no change, when I wanted to set 115, VemsTune protested about that, so I left 105, as I also found in different tutorial that I should get voltage between 3.9 and 4.1, not exactly 4.1 - the other WB02 controller value wasn't touched as I measured required 0.45v and 0.9v


Today I fixed the problems you pointed at - all the warnings was fixed, CLT/MAP table was set to 0 degrees the whole range and ignition outputs was set to 4 identical ones - I'm pleased to say that it fixed both problems, serial communication now is stable and LED connected to ignition output just flashes according to how I turn the dizzy :)

Anyway, I've a few questions and I don't want to start a new thread:

1) do I have to, upon ignition angle testing with LED, take into account "coil charge time" [time how long LED shines], or temporary set to 0,1 ms , or my brain will " see"  the timing mark at the moment when LED will go dark?
2) how 1-wire immo works - after setting correct numbers and enabling it, off it goes? Can I see somewhere, without enabling it, that VEMS sees that I put ibutton in it's socket, and identifies it?
3) Maybe you know correct charge time for mk3 golf ignition coil? Knowing that it's rather fragile, I would like not to risk with it.
4) In the future I'll need config switching, as I'll go for a LPG with separate control unit, for it I plan to use separate analog input, which has voltage divider attached to it. When config switching will be enabled, will it be like "config A - 0v, config B - some voltage", or more like "config A - 0v, config B - voltage above x volts" ? I presume that config switch switches between two complete configurations?
5) I'm using GM 1 bar MAP sensor, as found in weak and small engined 90's opels, but I cannot find exact kPa specification for it - do I have correctly guessed it to be 102 kPa, or it should be more? VemsTune is highlighting in red settings "MAP Range Unit - normal" and "Table kPa Unit - 2", is there anything wrong?
« Last Edit: October 17, 2017, 04:13:26 pm by msh »

Offline GintsK

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Re: Strange ignition output behaviour on bench testing
« Reply #5 on: October 18, 2017, 08:16:31 am »
Yes zero PW, sorry! You misunderstood something. You have to get voltage between EC18-7  and   EC18-9  as close to zero as possible. Usually it is done in Hungary quite well. So I guess you have wrong setting now.

1) Do not knew about brain, but even if light would be enough to see timing mark method is not correct. At cranking engine speed fluctuates a lot and you will get erroneous value.
2) No experience. Too embarrassing.
3) No. Start with 2ms and use oscilloscope. Usually output stage limit current when maximum reached. Go little beyond that.
4) Do not feed solenoid + wire to VEMS inputs because of high flyback peak. Better use additional small relay driven from that for switching clean ground signal for VEMS input.
5) From here http://www.robietherobot.com/storm/mapsensor.htm  Range 95.  Offset 5 or -5 - not sure, try. Normal and 2 are OK.

Offline msh

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Re: Strange ignition output behaviour on bench testing
« Reply #6 on: October 22, 2017, 11:56:28 pm »
Ok, I'll set the previous value.

What I should measure with oscilloscope - coil primary winding current?

I know about need to protect VEMS inputs and outputs from relay and solenoid coil pulses :) What I do not understand is what exactly VEMS expects from that input - so, if I'll set config A to, let's say, MCP3208 CH2, and config B to MCP3208 CH2 inv, A will be active with positive voltage on that input and B will be active with no voltage on that input?



I also recently got confused about injector settings - what exactly should I set to have batch fire? Does coil type primary trigger makes VEMS to expect batch firing and requires no more settings for that? I found that I should set injector outputs like this for all four injectors to open and ISV to work - are those settings fine for batch fire?



I hate to give stupid questions but I cannot find the answers...  >:(