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HELP : MX5 mk2 SEI - No spark
Barkalarr - 23/2/14 at 10:59 AM

I have an MX5 mk2 SEI 1999 it will not start as there is no spark.
I have checked the coil pack and the 2 coils are both reading 9.54k ohms on the voltmeter (spec says 8.5 to 12.5).
I have also used the diagnostic diode to read faults but cannot find any code tables for the mk2, the codes I am reading are:-

1 long flash followed by 6 short flashes.
1 long flash followed by 2 short flashes.
1 long flash followed by 4 short flashes.
1 long flash followed by 1 short flash.

I have also changed the crank sensor and am about to replace the cam sensor when it arrives.
I have checked the location of the ECU and there is no dampness of any kind.
If anyone can help with the diagnostic readings It would be much appreciated as I am running out of ideas.

rdodger - 23/2/14 at 11:29 AM

This may help.

http://www.miata.net/garage/Engine_Diagnostics.html


Code

Meaning


1

Ignition pulse


2

Ne signal


3

G signal


4

SGT signal (1.8L)


8

Airflow meter


9

Water thermistor


10

Intake air thermistor in airflow meter


12

Throttle position sensor


14

Atmospheric pressure sensor


15

Oxygen sensor (output too low)


16

EGR function sensor (1.8L)


17

Oxygen sensor (output not changing)


25

PRC solenoid valve (1.8L)


26

Solenoid valve (Evaporative canister purge)


27

EGR solenoid valve (vacuum)(1.8L)


28

EGR solenoid valve (vent)(1.8L)


34

34 Idle air control (1.8L)


36

Idle speed control valve

dave - 23/2/14 at 12:05 PM

Dont know if this will help, but i had a similar problem with my MK2 and discovered that the crankshaft position sensor was too far away from the crank. I moved it closer and it work.

Barkalarr - 24/2/14 at 08:55 AM

quote:
Originally posted by rdodger
This may help.

http://www.miata.net/garage/Engine_Diagnostics.html



Thanks, but at the top of this link it says "Note that this may not work for models newer than 1995 (OBD-II))"

Mine is a 99... any other ideas.... ?

britishtrident - 24/2/14 at 09:15 AM

If it has an OBD2 port get the codes read with a scanner/dongle.

Coil packs faults will usually just give misfires and trying to test one with a multimeter usually is a waste of time.

The odds are it is either the crank sensor or an immobilisers type issue.


Crank sensors usually fail either due to broken internal or external connections or build of swarf crap on the business end
Older crank sensors were Vr sensors which you could test with voltmeter but if it is Hall-Effect it is more difficult.

Barkalarr - 24/2/14 at 11:15 AM

All I've got is this diagnostic connector under the bonnet on the RHS (from the front)



Any more ideas?