Immobiliser problem

Hi guys recently did the clutch and starter motor and now I’m having problems with getting it going.

you can bump start it like a dream.

It’s cranks and fires and then dies immediately with the immobiliser light flashing before you start it though it’s a solid light.

ive got my key codes if I have to re add them but wondering if anyones got an idea and please don’t mention the stealership as they charged £200 for them to say they don’t know 
 

Assuming we're talking about the factory immobilizer system, you can remove the immobilizer from your list of suspects - when tripped, it inhibits both spark & fuel injection - the car will not start when bumped - it will not fire when cranked.

Focus on connections that may have been disturbed whilst replacing the clutch & starter motor - was the battery negative lead to the bell housing refitted during reassembly?

The reason I'm asking about this lead is if it's not there, the starter return current has to flow through other connections between the engine and the chassis - possibly the clutch cable and any other ground leads, from the intake manifold to the firewall, etc. - this has the possibility/probability of ground references changing and upsetting the ECU when the cranking current starts/stops.

Yeah all cables are back and connected up, been looking online and seems to be a problem some people have with immobilisers

First question - do the people having that problem have Jimnys?
Second question - are the Jimnys those people have fitted with immobilizers from the factory?
Third question - what good would an immobilizer be if you could simply "bump start" the vehicle and drive it away?

What I've described earlier is how Suzuki's factory fitted immobilizers function, you haven't told us what model Jimny you have (in fact, you haven't told us it's a Jimny, I assumed that), but that's how the immobilizer in my 2005 Grand Vitara works, and also the one in my 2021 Jimny - crank as long as you like, it'll never fire. (don't crank too long, you'll destroy the starter motor)

It's how most factory fitted immobilizers work, Mitsubishi does it that way, Nissan does it that way.

Yes few jimnys, among other cars,

Not to sound rude but I’m on a jimny forum so you’d assume so, no idea why you can bump it mate but it just does

With my after market flip key fob i have had problems somewhat similar when the immo-chip was on the loose inside the fob. started OK but then dies very soon after and the Immo-light flashing. I could always pull the key, shake it so the chip came closer to the antenna in the ignition lock (or so i thought) and restart.
Have not had this problem after swapping my dashboard cluster though (instruments and electronic board on the back of the speedo) . It should not have anything to do with this but now when i think of it, it could have been an intermittent electronic fault wich the car was full of with the old cluster.

Could it be something is lightly fried in yours as well like it was in mine?

I believe there might be some sort of timing issue where the immo-chip is checked at insertion of the key, and then checked again after a few seconds. Most of this happens in the ECU but the cluster has some influence on the communications as my car had ignition faults, stuttered, died without the ODB -plug attached, strange lights on the dash indicating faults that was not there and even released some of the smoke inside the ecu. ECU still works .