Won't Start !!

[Mikie711]

Out for a run on Sunday and the car cut out and would not restart. Stopped dead. Quick call to the AA and he checks it over and says there is no spark. Coil getting trigger from the flywheel sensor but no spark. Looks like the coil is dead. Change coil today and still nothing. Going to try changing out the emerald ECU for the standard one just to rule it out but a bit stuck now. Wondering if it is maybe a faulty cobra immobilser thats preventing the coil trigger from the ECU. Anybody got any tips/tricks etc.

[mac]

Don't you have a tick box option to ignore the imobiliser on the emerald ECU?

I would still be looking towards the crank position sensor though - unless the emerald is telling you 100% that it's getting an input.


Mac

[robin]

If the engine cranks and the fuel pump primes prior to cranking then the immobiliser components external to the ECU are working.

The emerald has an immobiliser configuration page that allows you to re-learn the code or disable the ECU's immobiliser function - if you configured it in the first place you'll know whether or not that option is set already. TBH I doubt that's your problem.

If the light on the emerald goes from red to green while cranking then you have a working crank position sensor/flywheel and the ECU is configured for the correct pattern.

If the engine cranks but the fuel pump doesn't run, check the inertia switch hasn't popped out; also you'll need to trace the rather tortuous path that the fuel pump wiring takes as terminal corrosion is common and this leads to poor contact, then heat, then circuit failure.

If neither the engine cranks nor the fuel pump runs then you have a faulty immobiliser relay, in all probability and it needs to be bypassed.

Assume you have checked the distributor cap/rotor arm?

Cheers,
Robin

[Mikie711]

Robin,
The fuel pump runs, have since discovered that I am getting a weak intermittent spark. The emerald light stays red, funny you mentioning that because I was sure it should have been green, but couldn't find any mention of it in the manual. Have tried changing the crank sensor but no different. However it is entirely possible that the spare I had isn't that great. Cap and arm fairly new but checked anyway and OK. Replaced the leads no difference. Looking at the emerald real time data it's getting trigger from the crank sensor, water temp is working as is everything else, weather the signals a correct is a different matter.
Gave up in the end and sent to Ricky Gauld (he set up the emerald for me). Will see what he comes up with and hopefully get it back in time for Saturdays hill climb!!.

OK just got the phone call to tell me the car is ready. The fault was caused by a porous rotor arm causing the spark to dissipate through the arm into the shaft rather than going to the plugs. A common problem with rover engines so I'm told.

Mike

[robin]

Robin,
The fuel pump runs, have since discovered that I am getting a weak intermittent spark. The emerald light stays red, funny you mentioning that because I was sure it should have been green, but couldn't find any mention of it in the manual. Have tried changing the crank sensor but no different. However it is entirely possible that the spare I had isn't that great. Cap and arm fairly new but checked anyway and OK. Replaced the leads no difference. Looking at the emerald real time data it's getting trigger from the crank sensor, water temp is working as is everything else, weather the signals a correct is a different matter.
Gave up in the end and sent to Ricky Gauld (he set up the emerald for me). Will see what he comes up with and hopefully get it back in time for Saturdays hill climb!!.

OK just got the phone call to tell me the car is ready. The fault was caused by a porous rotor arm causing the spark to dissipate through the arm into the shaft rather than going to the plugs. A common problem with rover engines so I'm told.

Mike

If the emerald light is red while cranking then I am 99% sure the emerald will not run the ignition and there is no point looking further downstream for other faults. If it's now running you could confirm that the light is turning green during cranking/whilst running. If it is and you are sure it wasn't before, then whatever other problems you may have had, you deffo have a problem in the Crank Position Sensor -> Emerald circuitry.

Cheers,
Robin

[ceejam]

The fault was caused by a porous rotor arm causing the spark to dissipate through the arm into the shaft rather than going to the plugs. A common problem with rover engines so I'm told.

Mike

Funnnily enough I was going to suggest you tested for that, as just diagniosed that on a rover 200 cabrio. Had the code reader on it, and everything was fine, cracking spark form the coil, but bnithing at the plugs. Cap off, point king lead at rotor arm and ZAP! Faulty rotor arm. Exactly the same breakdown symptoms too! Was running, stopped at lights, then wouldn't restart!

Funny how people usually suspect the Voodoo Box (ECU) when 99% of the time it's something external

Glasd you got it sorted, and shouldn't have been to expensive

[Mikie711]

£9 for the rotor arm £95 labour . However, unless you are aware that these engines are prone to this happening then I suppose it would take awhile to figure it out. I didn't catch it and I checked the rotor arm, looked OK.
You live and learn.

Mike