MS3 no-spark (REV built)
 

The car in question is a 94R, factory wiring, with a VVT swap done as detailed in the "Ultimate VVT swap" sticky.


Got the motor, in, MS3 plugged in, MAP sensor line, TPS calibrated, and I believe the wideband is calibrated (not sure as the car won't run).


I sent the head to the machine shop, re-timed the motor and replaced the timing belt. Timing marks line up, and Cam shaft lobe position verified. Crank sensor plate was installed with the center bowl depression facing inward at the crank, not the balancer. I also reversed the plate as a test, still no spark. I did verify the sensor having the correct gap to the trigger wheel.


I'm using 01+ coils, but the factory coil connector blue wire (94 chassis factory 12Volts), shows no power. I plugged in the stock 94 computer hoping the get power, no dice.

Then I find the 80amp main fuse is blown (no idea how, it was fine last week when I pulled the engine), so I replace it. Still no spark, still no power.




I'm using TunerStudio, Fuel injector Load is reading 100% (because the circuit is closed I assume?), but RPM reads "Not synced".

The program also shows "not-ready" in the corner.




Anything obvious I seem to be missing? I thought I'd check the forum while I waited for the sun to rise in Greece.




EDIT: MAP is reading 100kpa (I'd guess this is about right, as 1ato is 100kpa, that puts the shop at just under sea-level).

The drivers side ground is connected at the dip-stick mounting bolt (as the car was originally). The intake side only has 1 ground, which I have on the intake manifold.

Are you getting RPM in TunerStudio while cranking? Log?

No rpm signal via gauge. I'm about to pull off my plug and play harness and do a continuity test to confirm everything is going to the right input/output.



Log (hopefully) below.

Plug and play harness for CAS - converted to 01+ Cam/crank sensors checks out for continuity, and location of wires.

Would the Crank-sensor be the RPM pickup on the new-setup?

Also Pulled up the "test mode" feature. Output test mode inj/spark.


I plugged in the #1 plug wire (run by #4 coil pack in wasted spark), grounded the plug to the header. No spark, when set at coil A,B,C,D.

If you don't have 12V at the coils (blue wire), they won't work, so find that first.

With no RPM signal, the ECU will obviously not send fuel/spark, so you need to see why you don't have RPM, use composite logger for that (post the log here if you need help with that).

Now have 12V at coils.

Here's a log of cranking, one RPM gauge reads 0 constantly, the other is stuck at 99.Xrpm.


Bad crank sensor? The OE Tach input for the 94 coil pack isn't connected, but there's nothing to connect it to. How does the OEM VVT engine derive rpm? Cam or crank sensor?

Cam sensor is brand new.



This log includes 2 cranks, ambient temp about 60, jump pack booster hooked up because the battery is getting weak.



Map is now all weird too.

From my understanding the factory 94 tach/wiring works as such.

5 wires total (6 plug connector, 1 not used). Blue power, black ground, brown and brn/yel are the signal wires to the ECU. The 5th wire is black/white, and this is the output to both the factory tach, and the ECU itself.


So, with my current wiring, I do not have said tach output wire tied into anything, it's just heat-shrinked shut. CMP/CKP each get power and ground, and their respective signal output to the ECU. My understanding is that the MS3 would derive its' own tach signal from other (non-specified) sensors.




So, that would mean that the factory tach output wire which went to the factory coil packs is now irrelevant, correct? If so, how is MS3 intending to pick up the required RPM signal? Does it run directly off the crank sensor?

Okay, 1 issue fixed.

Cam/Crank signal wires to the ECU were reversed. 100% my fault, had my connector upside down when I pinned it.



Tuner studio now reads "ready", in green, in the left hand corner during cranking.


However, I still am not getting a tach signal, rpm readout just says "100", and the factory tach in the gauge cluster is not moving.


Cam sensor is brand new, I'm about to swap out the crank sensor for a new one for the hell of it.


Does this shed light on what may be the problem? I also attempted to start the car with the ignition set to "CAS 4-1". The engine is using NB sensors, but they're wired into the factory CAS wires, which feed the MS3. Should I leave my igntion set at the original "Miata 99-05" setting, or due to my wiring, is "CAS 4-1" the correct setting?



EDIT: I also quadruple checked the mechanical timing, it is still correct, no movement of the marks.

Leave it at Miata 99-05, grab a composite log.

I selected sensor 1 and sensor 2, which I believe are the cam/crank signals.


EDIT: Let me know if you need other signals graphed, the car is at work with me.

Did you say you are using sensor 1 and sensor 2 for cam and crank input?

Post MSQ before doing anything else.

The megasquirt uses cam and crank to figure out the RPM, similar to how every other ECU does. The coil tach output is JUST for driving the tach. Which you will now do using the megasquirt.

How did you wire the cam and crank sensors in?

Ah, gotcha about the tach. Ignition stuff is wired with jumpers for basic testing only. My new connectors will be here friday.


I used the base inputs from Rev. The waveforms appear to be the cam/crank signals.




Wiring:

I clipped off the factory 94 CAS connector, and spliced in GM weatherpack connectors.

One is black, this feeds power and ground to both sensors. There's a splice after the pigtail, so they share power/ground like the 94 CAS. Both are getting power/ground in the correct locations.

The other is white, this is my signal connector. I originally pinned it backwards (upside-down, whatever), so my cam/crank signals were reversed to the ECU. This has since been remedied.




Below is the .msq - Let me know if it's not attached right.


I find it VERY unlikely that the PNP unit Rev built/base-mapped is the source of the problem. My sucking, is likely the source. :facepalm:

The log you posted is a normal log, it's not a composite log (in the "Diagnostics & high-speed loggers" tab).

New, actually composite log, below. I was running a standard log while I had the comp. log screen up.


TPS is moving with little blips of the throttle.

There are 3 cranking attempts.

I repinned my coil connector after one got loose. New pigtails should be here today to eliminate that issue 100%.

EDIT: Coil connectors fixed, power at the top-most pin, signal in the center, ground at the base.

FWIW: I'm using a battery charger to maintain the battery, and while cranking I have it set to 12v Start.

I doubt this would effect the MS3 in anyway, but I thought I'd mention it.

Just a dumb thought.


My coil wires are run through the OE 6 plug connector. The OE 94 coil pack uses 2, 4 plug connectors. In the factory coil setup, two 6 plug connectors are looped to each other, which feed the two 4 plug connectors into the coil.

Is my system of tapping into the factory 6 plug connector okay? I have power/ground at both COP plugs, and all of the wires match the color chart.

No cam signal detected. Check your wiring for the cam sensor.

I reversed the power and ground (I think AllData has messed up diagrams). Colors all agree, but some plugs seem pinned backwards.


I can see what I think is the cam signal (red) in the log.

The center wire in the plug for the cam sensor, has continuity between itself and blue/yellow, cam input for the 94 harness.

EDIT: Also checked all fuses for continuity in the engine-bay fuse block, and the footwell fuse block.

Red traces in the graph are errors. The crank/cam signals are blue/green.

Tested continuity between the cam output signal wire at the connector, and the ECU connector pin, that is good. Power and ground are good. The two raised sections on the cam that run the sensor signal are intact.

Then tested the CAM output signal to the ECU, by waiving a screw-driver tip in front of the trigger. It's reading 4.7X volts. I also swapped in another sensor to check, still the same.




So I have the cam input set at "MS3 cam in", continuity between the sensor and the harness, output signal being created, power and ground.

What am I missing in this equation? I can't imagine there's an air gap on the cam sensor, it just bolts to the valve cover, and is sitting flush.

:confused:

I decided to take wiring out of the equation.

With known good 12v power and ground, I apply each to the pins on the sensor.

When hooked up to the multimeter, the center signal pin shows static output at 10.XX volts. Waving a metal screwdriver in front of the sensor changes nothing.

The basemap came with the cam port set to JS10, so change it back to JS10.

JS10 selected.


Here's a log. Should I try jumping the cam sensor output signal directly into the factory connect? Perhaps I have a voltage drop issue. Cam signal still red.

The vvtunner instructions have a pin out of the cam and cranks sensor if you can't figure out which wire is which.

I know u don't have vvtunner box juts thought the pin out might help you.

I found the yellow/blue wire on the factory ECU connector. That, and an ECU pinout, are what I'm using.

Cam signal is now in and ok.

However, on that log, it appears you have an issue with the crank signal, on the latter half of the log. I can't tell but if you have a somewhat weak battery, that could be it.

Can you grab a longer log?

Yes, the battery is injured. 11.7X volts. I have it on the charger, I'll get my next log with multiple cranks. I'll let the battery charger 12volt start keep the voltage up.

Log, 2 long cranks. Tach on dash is now quivering while cranking.

Popped the breaker for the battery charger halfway through the second crank, so voltage should drop there.

What's the realistic time I can crank the car without overheating the starter? I usually got for 5 clock seconds or so on OEM setup cars when I'm looking at a no-start.

The 10 seconds for OEM cars is not a protection for the starter, it's more a protection for the oil and cat in case the problem is the with the coils. I usually ask for a 10 sec log to diagnose cranking issues.

Here's a 10second crank.

A 143-byte log probably doesn't contain much data.

My bad, try this one

Looks like a perfect log this time.

Now try to fire the coils in the test mode.

I selected "output test mode - inj/spk".

I enabled test mode, selected coil A (1 and 4 trigger I believe), output interval 199ms, rpm 600, coil testing mode "one", Dwell set at 5ms.

Number 1 wire (powered by 1/4 coil) has a plug in it, grounded on stainless racing beat header.

Tried on "coil" A/B/C/D. No spark output. Burn page 1 failed - displays iff I hit "burn".

Trigger wire in the center of the 1/4 coil reads 0.2volts during cranking.

EDIT: On the plug itself, 12volts is the top pin, then signal, ground at the base.

Okay, new info.



I hooked up the 94 coil pack into the stock wiring, attached a plug wire, and test-mode gives me spark.


So, I then wired the 01+ coil-on-plugs into said stock wiring, test mode does not trigger spark. I tried both coils (powered via the 1/4 wiring), still no spark.




Is it reasonable to believe that I have two dead coils? Spark outputs through stock coil, wire in COPs, no spark.



When looking from the drivers side at the engine bay, the top plug in the COP connector is 12volts, then signal, then ground.

I swapped in another set of 01+ coils.


In test mode, I can send signal spark, and my multimeter picks up the change in voltage at the center wire in the coil plug. No spark output though.

I'm feeling as though I may be a complete moron. Spark signal is going to the coil-connectors, no spark coming out. No idea how this is happening.

Coil has 12v? Sending it to the correct pin? Good ground?

11.75volts at top coil-on-plug connector pin. Battery is a tad weak at the moment.

From looking at the mazda diagram, Power then ground, then signal, is the pin order for the 01+ connectors, descending from the top.



I can watch the trigger signal when I probe the connector with my multimeter. Yet, no spark output. I've tried 4 different coils.

A diagram I have says A = 12V, B = ground, C = trigger.

Edit: Looks like we have the same diagram.

So, if we both agree the wiring is going to the right places, where does that leave my spark output?


Lots of dead coilpacks?

So I fired up the old tunerstudio.


I have pulse width at the injectors. YAY!


I would imagine that means I have spark output now.

Perhaps my weak battery couldn't properly fire the coils? I have fuel for sure now, I can smell the flooded cylinders.

The plot thickens. Fuel is there.


However my timing light and multimeter both confirm no spark current through the coil wires. Would having signal and ground reversed have cooked the coils?


The main screen now says: Ready/Cranking/RPM Sync/Full rpm sync.

However, "SPK1/2" does not turn green. If it were to be green; Is this the idiot light for "yes, you have spark"?

SPK1/2 is to show if you are using spark table 1 or 2.

Why not try to fire it up with the 94 coils so see if everything up to the coils is ok?

IT RUNS!!!!!


You're awesome Rev. :likecat: :likecat: :likecat:



Kinda idling high, rich, wants to die if I give it gas, but I haven't set the timing yet either. I'll keep you updated.

Good to know man!

hey sorry to revive and old thread but did you need to add the CAS back but did you just plug back the old ignition from the 94?