Mk1 MX-5 wont start, any ideas how to diagnose would be greatfully received.

Technical Area Engine, Transmission, Exhaust etc
2

Just bought myself a 1990 1.6 MX5 none runner. After having a rummage around (both on the internet, and under the bonnet) the problem as I see it is lack of spark. There is fuel getting to the plugs, but no spark. I have done a fault code, and it comes up as 01 : Ignition pulse.
Problem I now have is what to fix/replace.
I have discounted the coil pack, as from what I have read, the car has a pair, and it is unlikely that both have gone, so car would still splutter on one. (Please tell me if I am wrong)
My other options (as I see it) are the CAS, or the old immobiliser (usual type fitted to early cars, Finishline).
Is there any way I can work out which one it is without spending a fortune on a new CAS.


Would the fault code still appear if it was the immobiliser?

I never got an alarm fob with the car, and have no idea if the immobiliser has been disconnected in the past or not.
Hope that makes some sense, and cheers for taking the time to read my ramblings.

(I’ll also pop the reg up on the forum in the hope that someone recognises the car, and may be able to shed some much needed light on to it.)

 

3

the finishline immobaliser will have an ignition and cranking cut. I seriously doubt the installer would have gone to the hassel of cutting the feed to the CAS in fitting the immobaliser. Ignition pulse code would point me to the CAS myself, maybe try getting hold of a friendly local MX5’er through the forum to borrow theres?

 

Dan

4

Cheers for the reply.  I have just got a CAS from the scrap yard, fitted it, still nothing.  Now that CAS could also be faulty, which is always the problem with scrapyards, but am going to turn my attentions (and multimeter) to the coil-pack, to see if there is any power getting to it. Thats presuming I got the right CAS, as it did look a little different, but presumed that was just down to a newer cast design.