I have a user output operating a low draw vacuum sol. it's set up inverted so it's on until it reaches 3800 rpm.
when I hit 3800 the tach drops to zero I get a bit of misfire, the revs will continue on up but no tach readout. (it bounces a bit)
It's operating the vac unit but no tach above the set threshold (3800)
I disconnect the + lead to vac. unit and all is well, tach reads fine no missfire (except no vacuum controll)
Using version 3 MJL
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User output kills tach and spark
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NITROPIXIE
- Posts: 704
- Joined: Sun Sep 07, 2008 1:54 pm
- Location: Fareham, GB
Just to make it clear what your saying, you have a low current draw, vacuum solenoid and the solenoid is activated until it reaches 3800 rpm.
At 3800 rpm and above the cars tacho doesn't work but then your output is not switched on.
Ok i think i get it. I would do what DannyP says and isolate the circuit with a relay as you have proved that when isolated the problem has gone. Sounds like too much current draw at some point in the circuity and kills the tacho. I would do this sooner rather than later just to prevent any possible damage that maybe caused if you continue to operate it like this.
Hope this helps
Ryan
At 3800 rpm and above the cars tacho doesn't work but then your output is not switched on.
Ok i think i get it. I would do what DannyP says and isolate the circuit with a relay as you have proved that when isolated the problem has gone. Sounds like too much current draw at some point in the circuity and kills the tacho. I would do this sooner rather than later just to prevent any possible damage that maybe caused if you continue to operate it like this.
Hope this helps
Ryan
1310 A-series Mini, lightened and built myself. V4 board and loving it
Rasputin22 - The Mini Forum
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Megajolt repair for the UK available
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I disconnected the the vacuum unit for now.
Here is what I have going on.
I am running a Toyota Variable Induction system (T-VIS)
The way it works is the the solenoid is energized (closed) at all RPMs below the set switch point.
When the preset RPM is reached the power to solenoid is switched off and it opens thus opening the induction control.
I have the user output set to inverted and 3800 RPM, so if I am not mistaken I should have a closed curcit until 3800
So why if it's a load issue is it a problem only when the load is absent?
You can see the sol. connection in the pic, the big black thing is an accumulator, the solenoid is tiny.
Here is what I have going on.
I am running a Toyota Variable Induction system (T-VIS)
The way it works is the the solenoid is energized (closed) at all RPMs below the set switch point.
When the preset RPM is reached the power to solenoid is switched off and it opens thus opening the induction control.
I have the user output set to inverted and 3800 RPM, so if I am not mistaken I should have a closed curcit until 3800
So why if it's a load issue is it a problem only when the load is absent?
You can see the sol. connection in the pic, the big black thing is an accumulator, the solenoid is tiny.
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NITROPIXIE
- Posts: 704
- Joined: Sun Sep 07, 2008 1:54 pm
- Location: Fareham, GB
I can't work it out at the moment if you say the output is inverted.
It doesn't matter on the size of the solenoid but it does the amount of Amps it draws. Can you put an ohmmeter across the two terminals of the solenoid? If its quite low then it could be drawing too much current for the megajolt unit.
If you look here
http://www.autosportlabs.net/MJLJ_V4_ve ... hift_Light
It dictates that you can only draw 500mA or 0.5A of current through the unit. As Resistance = Voltage / Current, then say 14v / 0.5A = 28 Ohms. If the resistance is less then this then it can cause problems.
Just as a general rule it is generally safer to use a relay to protect the megajolt unit from damage. If it does cause damage to the megajolt unit then it should be localised to the ULN2003 chip and isn't difficult or expensive to replace.
It doesn't matter on the size of the solenoid but it does the amount of Amps it draws. Can you put an ohmmeter across the two terminals of the solenoid? If its quite low then it could be drawing too much current for the megajolt unit.
If you look here
http://www.autosportlabs.net/MJLJ_V4_ve ... hift_Light
It dictates that you can only draw 500mA or 0.5A of current through the unit. As Resistance = Voltage / Current, then say 14v / 0.5A = 28 Ohms. If the resistance is less then this then it can cause problems.
Just as a general rule it is generally safer to use a relay to protect the megajolt unit from damage. If it does cause damage to the megajolt unit then it should be localised to the ULN2003 chip and isn't difficult or expensive to replace.
1310 A-series Mini, lightened and built myself. V4 board and loving it
Rasputin22 - The Mini Forum
Rasputin22 - MK1 Golf Forum
Megajolt repair for the UK available
Rasputin22 - The Mini Forum
Rasputin22 - MK1 Golf Forum
Megajolt repair for the UK available
Hello,
Excellent tips so far. NITROPIXIE and DannyP's analysis is spot on. As it turns out we have actually controlled this exact device via a user output on our turbocharged 4AGE. The standard user output should be able to drive the solenoid valve directly.
How are you feeding the power to the solenoid valve, EDIS module and megajolt? A common circuit, or separate? You may also check ground connection- make sure you have a good ground for the EDIS module and megajolt. make sure everything is grouded to a center location ("Star" grounding scheme).
Excellent tips so far. NITROPIXIE and DannyP's analysis is spot on. As it turns out we have actually controlled this exact device via a user output on our turbocharged 4AGE. The standard user output should be able to drive the solenoid valve directly.
How are you feeding the power to the solenoid valve, EDIS module and megajolt? A common circuit, or separate? You may also check ground connection- make sure you have a good ground for the EDIS module and megajolt. make sure everything is grouded to a center location ("Star" grounding scheme).
Thanks Brent for looking at this thread. I'm powering the T-VIS EDIS and Megajolt from a separate power sources with all being grounded at one point. When you ran the T-VIS unit on the turbo 4AG did you use an inverted user output?
I suspect it's a ground issue, glad to hear I don't need a relay.
you can see the project at this link from the Powered by MJ
http://www.autosportlabs.org/viewtopic.php?t=2454
I suspect it's a ground issue, glad to hear I don't need a relay.
you can see the project at this link from the Powered by MJ
http://www.autosportlabs.org/viewtopic.php?t=2454