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Sync loss and USB disconnection

Posted: Mon Dec 25, 2017 11:05 am
by loser
Strange things are happening - I've got my ms3 with ms3x connected and running my Honda s2000, it has run perfectly until I've got the VTEC connected.

I've used the injector e port (via the programmable on/off 1 under advanced engine to switch earth on a relay (powered from elsewhere)) which gives the 12v to the VTEC solenoid and at the same time goes to the nitrous in port to switch tables (Honda use 4 maps, 1 fuel map for low cam and 1 for the VTEC cam (same for the ignition maps))

It goes into VTEC fine (at 5,000 rpm) and revs to 7-8k before I lose sync, but at the same time the laptop disconnects.

I've messed with the cam vr conditioner (that has been a problem before, but the laptop stayed connected and let me log the cam/crank teeth) but now I get tuner studio tellng me I've disconnected.

It's also run perfectly fine using 1 map but won't now I'm using map switch.

I can't believe these aren't related (USB disconnection and sync loss) does anyone have any ideas?

(I know it's losing sync because when I reconnect my laptop (unplug USB for a few moments) the lost sync counter has incremented)

Re: Sync loss and USB disconnection

Posted: Mon Dec 25, 2017 3:38 pm
by Peter6000
Considering the synkloss and usb connection loss at the same time. I would take a close look at you 12V power and grounds.

Sent from my SAMSUNG-SM-J320A using Tapatalk

Re: Sync loss and USB disconnection

Posted: Tue Dec 26, 2017 6:35 am
by loser
Well some more messing today and it was 2 separate problems - for some reason pulling that relay (even though its impedence is 720 ohms) low through the spark e port the ms struggles with crashing the ECU and disconnecting the laptop.

The second problem was because I'd limited the first map to ~7k rpm and intended to have the second map (which was from 4.5k to 9k rpm.) Take over.. Which it wouldn't for some reason

Re: Sync loss and USB disconnection

Posted: Tue Dec 26, 2017 9:29 am
by billr
Do you have a diode across the 720 ohm coil of that relay? Is the relay coil being powered only from the 5V from the spark E output, no connection to other 5V or (gasp) 12V?

If you want help with the table-switching, best to:
:msq:

Re: Sync loss and USB disconnection

Posted: Wed Dec 27, 2017 10:47 am
by loser
It was being grounded by the injector e port, but now I'm grounding it through the vvt port - it was pulling 12v low (ie the relay sees a constant (well switched with ignition) 12v, and then the ecu completes the circuit to ground). The external 12v source comes to the relay independently so the ms won't see any noise

I didn't have any flyback diode when it was connected to the injector e port, but since connecting it to vvt I've enabled the flyback clamp, which should stop any noise?

Interestingly connecting the relay to power and ground externally of the ecu (and hence activating it - no ms involved) also makes my laptop disconnect. Wtfffffff

Using a solid state relay if you think that could matter?

Re: Sync loss and USB disconnection

Posted: Wed Dec 27, 2017 10:53 am
by loser
Sorry - it's a subminiature standard relay - not a solid state

Re: Sync loss and USB disconnection

Posted: Wed Dec 27, 2017 8:05 pm
by billr
Oops, I as thinking you were driving it from the spark E output; my mistake, sorry.

How about putting an ammeter in that circuit to see how much current is being drawn? Or, use one of the spare analog inputs to log what the 12V is doing, or voltage across a shunt in that circuit? Maybe power that troublesome circuit with a separate battery (or simple diode/big cap '"power supply") to buy enough time for the MS to log some of this before it dies. I'm rambling, I know... time for my ice-cream!

Re: Sync loss and USB disconnection

Posted: Thu Dec 28, 2017 2:06 am
by loser
Measured it yesterday and only a few hundred milliamps, the only thing I can think of is that the engine is poorly earthed, since that's the only thing the VTEC circuit and ms were sharing (engine ground), it's snowed here so I might not get much work done on it today (and I'm getting a little sick of banging my head against the wall!)

Re: Sync loss and USB disconnection

Posted: Fri Dec 29, 2017 9:14 am
by loser
So 2 further days of oversize earths, running new earths and adding flywheel diode to the relay it still wouldn't stay connected to the laptop..

So I tried my dad's laptop.. And it only works.. Arghhh.

Any ideas what that could be? Mines quite an old dell xps m1530, my dad's is a dell n5050, I know different manufactures use different USB protection but these are the fking same!

Well that was annoying...

Re: Sync loss and USB disconnection

Posted: Sat Dec 30, 2017 1:09 pm
by loser
Another day of experimentation and VTEC seems to be interfering with the crank and/or cam signals, I'm going to try to mount the relay next to the VTEC solenoid so no (not so) major current flows through the harness at all... Headache!

Re: Sync loss and USB disconnection

Posted: Sat Dec 30, 2017 11:00 pm
by billr
"So I tried my dad's laptop.. And it only works.. Arghhh."

That confused me. Do you mean all works fine when using your dad's laptop?

If your laptop is old, does it have a 9-pin RS-232 serial port? If so, try that. USB has been more finicky for me than RS-232. Maybe newer USB driver chips have eliminated some problems.

Re: Sync loss and USB disconnection

Posted: Sun Dec 31, 2017 7:51 am
by loser
Yeah it works fine on my dad's dell, but not on mine - neither of us have an rs232 on our laptops.

Even with the VTEC relay in the engine bay it still breaks connection from my laptop (even doing the ground switching externally from the ECU), except when the VTEC relay doesn't drive anything (VTEC solenoid disconnected)

The VTEC relay will drive a bulb no problem, but the VTEC solenoid is still a problem

Interestingly it's also showing lost sync without it having been cranked.

Re: Sync loss and USB disconnection

Posted: Sun Dec 31, 2017 8:13 am
by loser
Even hotwiring the solenoid directly to the battery and earthing to the block causes the laptop to disconnect.. Argh.

Re: Sync loss and USB disconnection

Posted: Tue Jan 02, 2018 6:18 am
by Yves
On my Dell it does it occasionally as well. Never found the cause.