MK1 Cut out wont start, please help

Technical Area Engine, Transmission, Exhaust etc
2

Hi, i have a MK1 K reg 1.6 SE which I have owned for three years now and been an absoloute joy until last weekend. Whilst driving it cut out at around 60 and wouldnt re start.

Once towed home I have taken a look at the fuel pump, bridged out FP/GRD on diagnostic box and the pump starts, bridged out light green wire on fuel relay and it clicks, so all ok.

I tested for spark and only getting spark on 1 and 4, would that lend itself to a coil pack ? If so are there any tests I can do before replacing ? If I need a new one what do I need to look out for and where ?

Many thanks in advance !

3

Sounds like coil pack.If buying used, look for burnt plastic insulation, and corrosion where the plug wires fit. The insulation around the wiring gets heatcycled and stuffed with oil, and gets brittle. MX5parts are indicating out of stock, with nothing on the way.

RockAuto are offering a choice of new pattern replacements for between £27-75, with Delphi and Beck/Arnley parts listing at £88-75, a fraction of the Mazda price.
https://www.rockauto.com/en/catalog/mazda,1990,mx-5+miata,1.6l+l4,1190876,ignition,ignition+coil,7060


Delphi ref. GN10771

The Beck-Arnley part looks nice, using torx screws for construction

This appears to be a pattern part that will do the trick:
https://www.ebay.co.uk/p/Intermotor-12414/1037344187

ADL (Blueprint):
https://www.simplycarparts.co.uk/products/adm51474

So, the more you look, it seems there are plenty of pattern alternatives. ADL are OE quality.

Rock Auto is a US supplier, but they price shipped prices to the UK, and can be very reasonably priced even allowing for VAT/duty (they take care of that). Bu Delphi is sold here, so the Delphi cross-reference should help. I notice Delphi offer a 36,000 miles/ 3 year warranty in the US. Would be nice if they did that in the UK.

If you can get one for about £100, I would say its not even worth considering a used part. These are wear parts, and the newest will now be 22 years old. Commercial breakers are asking £60 for parts getting on for 30 years old, with I suppose a 30 day warranty. They might last another 30 years, they might last 31 days.

https://www.mx5heaven.co.uk/product/coil-pack-1-6-3-pin/



Cheap new:
https://www.buycarparts.co.uk/oen/b61p1810xb

4

Very likely coilpack with a remote possibility of it being low tension circuit wiring to that half(unit) of the coilpack.

MK1 1.6 is a very reliable coilpack but unlike the 1.8 and MK2 the two units cannot be swapped around to see if the problem goes to cylinders 2 & 3.

I would fit a used original Mazda coilpack if required. Borrow one off another car to test if you want to be sure that is the problem.   

5

Many thanks both, I will see if I can borrow one to give it a test.

 

Cheers Ben

6

Hi Moscar,

My money would be on the Igniter (small black plastic thing on the drivers side wing) as your symptoms are exactly the same as mine, I tested Leads, Plugs, coil pack, CAS, ECU and then finally the igniter which I wished I’d have tested first as it is the easiest to get to.

If you have a multi meter then you can compare your readings to mine to see if your igniter is the possible cause:-

Bad Igniter

OC1 - 47.7 tested at 200K ohms

IB1 - 1.965 tested at 20K ohms

VB - 11.7 tested at 20K ohms

TAC - 13.81 tested at 20K ohms

GND - 1.178 tested at 2k ohms

IB2 - 3.19 tested at 20K ohms

OC2 - 2.5 tested at 200K ohms

New Igniter

OC1 - 48.3 tested at 200K ohms

IB1 - 1.792 tested at 20K ohms

VB - 11.75 tested at 20K ohms

TAC - 13.83 tested at 20K ohms

GND - 1.186 tested at 2k ohms

IB2 - 1.79 tested at 20K ohms

OC2 - 48.3 tested at 200K ohms

 

As you can see the OC2 reading was massively different between the good one and bad one which will hopefully give you something to compare to.

This is a link which may help as well 

https://forum.miata.net/vb/showthread.php?t=251644

 

If it is the Igniter then I purchase a used one from Autolink and a new one off Ebay from Hong Kong which were both around £25 - 30. I thought it best to buy a new one as well because the one from Autolink will have some milage on it so could fail soon.

Hope you get it fixed soon.

7

Hi I have tried another coil and again just 1 & 4, so will look for an ignitor