MakeEverything
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| posted on 22/3/11 at 01:38 PM |
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Megasquirt Voltage Limits
Anyone know what they are for normal operation of V2.2 MS1 running EDIS please?
When cranking my voltage was dropping to 8V, so im wondering if thats the cause of no spark / trigger signal.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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MikeRJ
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| posted on 22/3/11 at 02:05 PM |
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That is very low, suggests a dying battery or some high resistance connections somewhere. The MJ will need a couple of volts overhead for it's
internal 5v voltage regulator, so if it was dipping down much below 8v, even briefly it could cause problems. I don't know the operating
voltage range of the EDIS, but I doubt it's much lower than 8v. If you disconnect the MJ and just leave the EDIS module connected will it start
ok?
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MakeEverything
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| posted on 22/3/11 at 02:17 PM |
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quote:
Originally posted by MikeRJ
That is very low, suggests a dying battery or some high resistance connections somewhere. The MJ will need a couple of volts overhead for it's
internal 5v voltage regulator, so if it was dipping down much below 8v, even briefly it could cause problems. I don't know the operating
voltage range of the EDIS, but I doubt it's much lower than 8v. If you disconnect the MJ and just leave the EDIS module connected will it start
ok?
Its megasquirt, not megajolt.
If i disconnect the MS ECU, then the fuel pump doesnt run, and the injectors dont operate.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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ed1801
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| posted on 22/3/11 at 03:33 PM |
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My v3.0 with edis will start even when the voltage drops to ~6v on turning it over. This was after extended cranking and not normal. The datalog
showed it zigzaged between 6&10 volts in time with the chug-chug-chug from turning it over.
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MikeRJ
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| posted on 22/3/11 at 03:35 PM |
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quote:
Originally posted by MakeEverything
quote:
Originally posted by MikeRJ
That is very low, suggests a dying battery or some high resistance connections somewhere. The MJ will need a couple of volts overhead for it's
internal 5v voltage regulator, so if it was dipping down much below 8v, even briefly it could cause problems. I don't know the operating
voltage range of the EDIS, but I doubt it's much lower than 8v. If you disconnect the MJ and just leave the EDIS module connected will it start
ok?
Its megasquirt, not megajolt.
If i disconnect the MS ECU, then the fuel pump doesnt run, and the injectors dont operate.
Oops, me being daft again sorry. You should still be able to check for a spark during cranking however.
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matt_gsxr
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| posted on 22/3/11 at 04:03 PM |
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If I turn off when logging I get voltages as low as 5.3v reported from the MS. So the electronics are still working down there.
I get around 8.5V whilst cranking and sometimes a bit lower.
Not running EDIS though, although I am running the sparks.
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coyoteboy
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| posted on 22/3/11 at 04:05 PM |
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Normal cranking sees me at 7-9v depending on ambient temps, no problems with resets. IIRC it has an LDO regulator so it should be fine fairly close to
5v. Everything else will go to pot though, unless you've been really good with your calibration, things like injector opening times and dwell
could be WAY off due to the lower voltages.
If you set it up on the laptop logging you'll get notification in the logs if it resets. If it's just not seeing the sensor/triggers
it's likely to be more down to your sensor setup.
[Edited on 22/3/11 by coyoteboy]
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omega 24 v6
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| posted on 22/3/11 at 05:38 PM |
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If the voltages get too low then it should show up as resets during cranking.
i.e do a data log while cranking but DO NOT turn the key off while doing so. ign on crank for a time then release. |Do it a few times and look for the
reset line ( red line on the graphs)
If it looks wrong it probably is wrong.
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MakeEverything
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| posted on 22/3/11 at 06:27 PM |
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Thanks Fellas. I think it might be something else then. Im on charge at the moment, so will find out later tomorrow.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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omega 24 v6
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| posted on 22/3/11 at 06:34 PM |
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Post up your msq
Was it running before??
Not really up on edis but you should get a spark even in " limp home mode" unless its not seeing a crank sensor signal.
If it looks wrong it probably is wrong.
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ashg
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| posted on 22/3/11 at 07:13 PM |
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check the pip and saw cables between the edis and the ms. even with ms disconnected the edis should still produce a spark at 10deg btdc
i have seen my ms working down to 6v on my test bench, and its a ms3 with every option on the list meaning its more power hungry than most. it can
drain a brand new 9 volt square battery in 15-20 mins lol.
go back to basics crank it over and scope the vr sensor to make sure its giving output, check the edis is getting power. if it is scope the tacho
output pin and you should see the rpm pulses. check the coil has 12 volts to the middle pin then try tapping one of the outer wires against a ground
and it should spark dont hold it grounded for long or you will blow the coil.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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