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-   -   Wiring gremlins - vvt / ms3 (https://www.miataturbo.net/megasquirt-18/wiring-gremlins-vvt-ms3-91287/)

adryargument 11-21-2016 04:36 AM

Wiring gremlins - vvt / ms3
 
So I'm having a few wiring issues that recently popped up.

Recent changes:
- engine swap from 00 to 01
- wired turbo timer spliced into the 3 ignition wires. These are individually wrapped and look fine.
- Changed to standard 01 coils with engine swap. Just changed back to shaved Toyota cops due to misfiring on stock coils.
- cut aerial power

Vvt didn't initially work. So I did a few tests with no success then went for a drive and it suddenly worked. So it was a sticky solenoid. Worked d for a month or two.
I just pulled apart the head and now I have the same problem. But before I got to looking into the filter and cleaning it etc, I experienced:

- car started randomly cutting out
- blown ignition fuse
- lc1 wideband continuously flickers on off when car turned from on to off
- relay under dash flickering sound

All these issues disappeared when I disabled vvt.
And i have driven without vvt for last few months and she's been fine.

So I'm trying to get vvt going again. Now im experiencing the same flickering wideband display and continuous relay under the dash sound when car is turned off. The only way to stop this is to remove vvt fuse or disconnect the solenoid.

I have tried running vvt off nitrous output and it's the same issue. So obviously the ecu is getting power from the vvt line which seems to be causing this / bridging to the lc1.

I checked continuity from:
- chassis to coil ground : yes
- chassis to coil 12v : yes - wtf?

So. I'm assuming my coil wires are shorting somewhere.

The end. I think at this point I'm just thinking in text form.

Edit: running vvt directly off battery instead of coil 12v is same issue

adryargument 11-21-2016 05:07 AM

Now I have looked at all the wires I have done. And they are all heatshrinked with no visible shorts.

Could the 10000uf capacitor provide the continuity positive from 12 to grd on the coil?

Also if I turn the car key from ig to Acc. Motor stays on. Only when vvt solenoid is connected.

adryargument 11-21-2016 05:26 AM

If vvt is wired up, but signal wire from ecu is disconnected. Car turns on and off and It functions normally.
If vvt wire to ecu is connected, but solenoid 12v is grounded. Functions correctly with no vvt.

If car is on, solenoid 'test' set to 36deg where it works. And I connect the vvt wire to ecu. Vvt activates and engine dies, then I turn key off and lc1 stays on flickering with relay flicker, around 5 times. Per second.

I'm test mode with vvt. Nothing happens from 0 to 34deg value. If I hit 35deg. It activates.... Then shit happens.

adryargument 11-21-2016 05:30 AM

Dodgy solenoid?
Does this happen or very unlikely.?

adryargument 11-30-2016 05:52 AM

Ignition wires seem fine from the firewall to plugs. Don't ask me how I know, wire snips were used, alot.
With only two fuses plugged in. The 15a meter, and the 15a engine. The ignition wires are grounded to the chassis.

Considering my left speaker stopped working yesterday I'm going to work through the all the radio bullshit then work my way through the old 02 plug harness and whatever else is on that circuit.

Braineack 11-30-2016 07:45 AM

i wanted to help, but i stopped reading after turbo timer...


what are you using to control VVT, an output on the expander board?

adryargument 11-30-2016 09:44 AM

Vvt output on rev's ms3 basic. 5a.
Also tried the nitrous 2a to rule out the ecu. Same issue.

adryargument 12-01-2016 01:18 AM

So ecu, radio, EVERYTHING is disconnected.
Still shorting. Must be in the harness wiring somewhere..

It's the black/white 12v wire that is part of the injector harness and ends up at the coils.

Injectors and coils have been disconnected. So its somewhere after the 20a engine fuse and before the plug on front of engine.
Next step is to disconnect the big blue plug that connects the dash harness to the engine bay harness. to eliminate one or the other.

Diagrams tell me this wire splits to 3 places.
- coils - Fine
- engine relay - ???
- O2 Sensor heater - ??? Disconnected? Using LC-1 so maybe this is faulty somewhere / filled with oil dirt water.

adryargument 12-01-2016 01:48 AM

So if only the 'meter' fuse is in. + the 80a in the engine bay.
Pins 3 and 4 on the key barrel plug ground out on the chassis.

Which is ig2 and Acc.

Pulling the large blue plug in the firewall which separates the engine bay harness to the dash harness. Removes the grounding from the black white coil wire in the engine bay.
However when tested the same wire on the blue plug also shows a negative.

My powers of deduction point to that wire between the firewall and coil plug.

However this ignition barrel bs concerns me


Bah just noticed the plug plug goes under the dash. Not directly into the firewall. Fml

adryargument 12-01-2016 04:34 AM

this sucks.
fin.

progress is drier than a nun.

im thinking of stripping the engine harness. its a 99% waste of effort and will not work, but it will be positive to my mental well being at this point in time.

adryargument 12-01-2016 02:40 PM

Alrighty.

Grounding from ignition barrel IG1 and ST.
IG1 powers the white black ignition wire. So somethings wrong in the ignition system. (Turbo timer has been snipped, its not this)


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