Replacement Immobiliser Suggestions



Our Eunos Roadster 1.8 had intermittent electrical issues resulting in the replacement of the coil pack and ECM a few years ago - problems that persisted, and resulted in the car being SORNd until recently.


We are now getting it back on the road, but have just suffered another coil pack failure.  The guy at the garage said that the immobiliser is at fault, and has removed it (it’s a Laserline immobiliser).


I’ll have a look online at options but, in the interim, are there any suggestions for a new aftermarket replacement?



Can’t quite see how a fault with an immobilser can cause a coil pack failure, but a suggestion for a replacement device would be from here;

Needs input from Rhino IMHO.


I’m not convinced, but Freelance Mazda have a pretty good reputation, so will wait and see if the intermittent electrical issues return or not.


I’m certainly glad that I had a spare coil pack in the shed :slight_smile:



The immobilizer will not kill the coil packs unless wired up incorrect, what kills the 1.8 MK 1 NA packs and CAS is leaving the ignition on without them running, early 1.8’s had a 4 pin packs , later had the 3 pin the same as the MK 2 NB 1.8’s, did your garage do their home work and read up??? and check for furring in the coil pots first, i bet not as that is the biggest issue that happens to them all, (1.6 MK 1 NA 1989 to the 2005 models 1.8 or 1.6 makes no difference with them going furry) which in turn furs up the HT leads connection giving none or weak spark, which is easy to put right with a good clean with fine wire wool and contact cleaner.


Regarding imobilser.


Back in the 80’s when hot hatches were being stolen for kicks, I came up with an exrememy cheap and simple solution.

A hidden rocker switch wired in to the earth wire of the fuel pump relay.

Flick the switch and the fuel pump would be rendered useless.

The car would start but would only run for a few seconds, before cutting out.


I also did the same on a mates XR2, only instead of a hidden switch, we bought a second hand Ford switch from a breakers, and fitted this to a blank space in the fascia.


No fancy electronics to go wrong, just a good old manual switch.

OK, so it had to be applied manually, but took little in the way of habit.

Did this issue get sorted, and feed back???


Got the car back on Friday.


Old Laserline immobiser has been removed, spare coil pack installed, and no more symptoms.


On the plus side, the (new) battery was draining overnight - that has now stopped.