mk1 mx5 no spark

[Tubs]

hi lads bought an mx5 the other day, towed it home cus the cam angle sensor was leaking oil,it still is cus i hvent replaced the o ring yet, got home and started the car drove it down my road and parked it in my drive, went to start it the next day and it wouldent start, found the problem it had no spark but i cant fugure out why it dosnt have spark i went though all the immoiliser and that isnt the problem, i cant figure it out :/ she is a 94 jap 1.8, any help would be much appreciated .

[MX5Spares]

94 jap would not have original immobiliser but maybe aftermarket one.Is battery flat??,is engine turning over??Presuming its manual and not automatic??Have you tried pressing the clutch down fully before you start it as some have switch on clutch pedal as safety feature but usually jap mk2,s.Is there an alarm on it?? Give us a few hints ....

[Tubs]

Ya it was an aftermarket immoboliser, engine is turning over and is getting fuel, its a manual there was an alarm fitted but it was taken out at sum stage, i dont get how it was working fine and then the next day it has no spark

[MX5Spares]

Is there a fob with the alarm ,like on dash or anything.Some have the type where you touch the fob off the contact on the dash front.Uusally have red led showing though. Firstly check all the earths on the engine,PPF frame ( near the diff) and check all the fuses,battery connections etc just to illiminate anything simple.

[MX5Spares]

Why dont you call the previous owner and enquire as to is there anything funny about starting it.Hardly broken timing belt and CAS is not turning?? Very unlikely.I still think its back to alarm issue or loose alarm wires shorting from not being insulated properly Other than that try another CAS sensor for starters and go from there.There is diagnostic check you can do with resistor and piece of wire if you check the net but not all electrical compononents are run through it.

[Tubs]

Ya i have the fob it works cus the car wont turn over if i dont touch the fob off the contact i traced all the wires for the alarm and its all fine, i even got onto the fella that fitted the alarm in england and he said that the alarm will have noting to do with the spark, ya the previous owner dosnt know either the car started fine when i viewed it and started when i got home, i did nothing to it but park it up and now it wont start ill try the earths and ill try the diagnostics test

[93 Mk1]

I would suggest you start with the basics. If there is no spark (by earthing the spark plug against the block) then check the coil pack (assuming
your plugs leads/caps are fine). Is there voltage present at the low tension side of the coil pack ?

[Steve]

I'd try swopping in a known good CAS first as autocheck suggested.

[Tubs]

I think i found the problem, i opened the ecu to have a look and found abit if burn on circut board, you can see it in the pic below its on the top half of the picture
https://fbcdn-sphotos-h-a.akamaihd.net/ ... 2950d64e68

only problem now is finding another jap 1.8 ecu to see if that whats causing it not to start

[MX5Spares]

We have good used ECU,s here

[Tubs]

We have good used ECU,s here

pm sent

[Tubs]

rite i got a new ecu and that didnt work and i tested the coilpack and thats grand, i read on another forum that if the CAS o ring is leaking that the oil can contaminate the sensor and mine is leaking so ill give that a go next, will i need a new cas if its contaminated with oil or can i just clean it ?

[Tubs]

anyone know ?