MS3+MS3X Stopped working - No Cranking/RPM Signal

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Rothko
MS/Extra Newbie
Posts: 10
Joined: Sat Dec 21, 2013 10:37 pm

MS3+MS3X Stopped working - No Cranking/RPM Signal

Post by Rothko »

I have been running an MS3 with MS3X on my JDM 1992 Eunos Roadster with minor mods for a few weeks with no problems (really enjoying it!) but recently it simply stopped working. I came to my car in the morning and it just cranked and didn't start - it was working absolutely fine the night before when I parked it...

I reverted the car back to stock and it ran horrifically! Misfiring, smoking, sputtering, running super rich then lean and stalling - completely undriveable but after swapping in a different CAS it runs fine stock but still doesn't run with the MS3.

Tuner studio detects the correct throttle position, temps, pressure, but I'm sure it used to detect the car being cranked - nothing now - just a change in MAP.

High speed loggers show a CAM signal but no CRANK (and hence no SYNC/RPM) so I checked that the pots on the VR circuit are still tuned which they are (I can't see how they would change overnight) and visually inspected the board for any obvious damage (nothing).
Image

I have attached a log from when it was working and a log and composite log from when it failed to start. My msq (attached) has not been changed between the working and non-working state.

Really at a loss as to how it could stop working overnight - the only thing I can think of is that it overheated as I was using the heater on high in the foot-wells that evening...
1992 Eunos Roadster, stock 1.6 B6 engine, MSPNP 1.3, Z32 Turbo (TB02/22), Evo9 Intercooler, RX8 Yellow Injectors (Flow tested 405-411cc/min@2.5bar), DIYAutotune boost controller, Walbro 190lph fuel pump, no AC, no PS.
Matt Cramer
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Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: MS3+MS3X Stopped working - No Cranking/RPM Signal

Post by Matt Cramer »

Does the problem only happen on the car, or can you duplicate it on a Stim?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Rothko
MS/Extra Newbie
Posts: 10
Joined: Sat Dec 21, 2013 10:37 pm

Re: MS3+MS3X Stopped working - No Cranking/RPM Signal

Post by Rothko »

Thanks for the reply. Sadly, I don't have a stim to test it with.

I'll try to get one. Is there anything I could be checking in the meantime?
1992 Eunos Roadster, stock 1.6 B6 engine, MSPNP 1.3, Z32 Turbo (TB02/22), Evo9 Intercooler, RX8 Yellow Injectors (Flow tested 405-411cc/min@2.5bar), DIYAutotune boost controller, Walbro 190lph fuel pump, no AC, no PS.
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: MS3+MS3X Stopped working - No Cranking/RPM Signal

Post by Matt Cramer »

Can you put an oscilloscope on the crank sensor?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Rothko
MS/Extra Newbie
Posts: 10
Joined: Sat Dec 21, 2013 10:37 pm

Re: MS3+MS3X Stopped working - No Cranking/RPM Signal

Post by Rothko »

I don't have an oscilloscope but the car runs on the stock ECU and (I know it's primitive but) I get a definite changing signal from the crank sensor on the voltmeter.

I can get hold of an oscilloscope though so if you feel it will help further diagnose the problem I will check with one this weekend.
1992 Eunos Roadster, stock 1.6 B6 engine, MSPNP 1.3, Z32 Turbo (TB02/22), Evo9 Intercooler, RX8 Yellow Injectors (Flow tested 405-411cc/min@2.5bar), DIYAutotune boost controller, Walbro 190lph fuel pump, no AC, no PS.
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