Sigma Roadsport - starting issue

[Guest]

I've recently had a starting issue with my Sigma engine Roadsport. Occasionally hesitant on starter button, but the other day just the "click", both from starter button and when turning ignition key. After several tries it started OK and has been a couple of times since. Hate being unsure if it will start, is something like the relay about to fail?

[Domus]

Guessing at key fob dongle thingy (technical term) not connecting with aerial. Mine did this when I used a new neoprene lanyard as a keyring. Very strange. My aerial hangs in a loop behind the ignition barrel, key in, turn, touch dongle to aerial and away we go. The neoprene strap was getting in-between and preventing activation.

[Simon Ferguson]

I spent a year trying to start my Sigma Roadsport SV until I phoned Caterham about something else and said by the way I have a lot of trouble getting the dongle thing to unlock the ignition. Oh yes the nice man at Caterham said the aerial is all nice and tightly bound round the steering column with a cable tie, snip the cable tie not the aerial and unravel it a bit. What a relief the time I spent waving the dongle under the dash!!

[Guest]

Thanks for the comments. I don't think the problem is connected with the immobiliser as this seems to deactivate OK.

[fauxae]

My Sigma has been doing that intermittently. At the last service Caterham said a replacement starter motor is needed. The K-click article in July Lowflying has me thinking though. Alan

[10uptobase]

Did a search and came up with this thread as I seem to be starting to get the same problem on my sigma 150 raodsport. ☹️

 

From cold, originally there was a solenoid click but no spin up of the engine. Second time started normally. Then it took a couple of attempts. Yesterday it was about 5th press before the starter engaged and started the engine. I replaced the battery not that long ago, but am planning to check the voltage at rest and when running to ensure its charging / holding a charge OK. Next on the list was security of power leads / earth to the starter. Any other suggestions???

 

thanks!

[Garth]

How old is your battery? I had starting problems on my Sigma recently - did various checks with a voltmeter and alternator was fine! Seems the battery had just had enough! Jump started it and it turned over fast and started just fine. New battery and been fine for 2 months!

[Guest]

I started this thread - and ultimately ended up with a new starter motor. Has worked perfectly every time since then.

[10uptobase]

Battery was new either last year or the year before...

 

[Jonathan Kay]

Quoting 10uptobase: 

... but am planning to check the voltage at rest and when running to ensure its charging / holding a charge OK. Next on the list was security of power leads / earth to the starter.

I'd add battery voltage while cranking.

 

Jonathan

[10uptobase]

hi and thanks. what should i expect while turning over?

 

Dave

[Jonathan Kay]

From what others have written I think you need at least 9.5V while cranking. There are two issues: what the electronics need to be happy and what the voltage drop tells you about the state of the battery.

 

Jonathan

[10uptobase]

thanks !