Peter_Bullen

Thanks. I think it must be the same issue.

Thanks for the reply. Guess this confirms my thoughts. I assume your engine is the same as mine... a Ford Sigma 1600? Do you know what was wrong with the slave cylinder? Had you done many miles? This was meant as a reply to #2. Pedal stop is set correctly .. thanks.

I am experiencing some odd behaviour with the clutch in my 310S. The clutch feels Ok and then suddenly the clutch pedal goes 'floppy' and sometimes there is no resistance at all. It comes back and you can drive it (so far) but its all rather disconcerting especially when the pedal goes right to the floor (with no resistance). I have bled the system, checked for leaks etc and all ok. This behaviour seems to start once its warmed up but varies from day-to day. Its OK when cold and sitting in the garage.The car has only done about 2800 miles and oddly enough I experienced something similar when i first built it (roughly 2 years ago). Brought it up with Caterham at the first check. They bled the system and declared it OK. Its been Ok ever since until Thursday when it started happening again, after about 60 miles! Same again on Sunday after about 12 miles. Anyone experienced this? I have a feeling it maybe to do with the slave cylinder sticking, once warmed up. Is this a possible reason?

I finally tested the car with the new relay and discovered that the speedometer wasn't working. Closer inspection revealed a loose wire in the speed sensor plug. .I am wondering if this was the cause of the relay failure. Pleased to say its all up and running now. Thanks for all the helpful suggestions/comments

I have been reflecting on the relay failure causing the ignition to cut out and wondering what can cause a relay to fail? If there is a sudden current surge could the relay act like a fuse. ie a short causing a current surge causing the relay to fail. I guess I am pondering on the very wet conditions and still thinking that was the reason for the failure but there was no evidence of any water around the relays or ignition switch or immobiliser. Any thoughts?

Hi Jonathan. The fault occurred at speed. it was as though I had switched the ignition off and the immobiliser came on flashing 'normally'. I tried the ignition switch and nothing happened no instruments,etc absolutely nothing. The immobiliser still flashing and lights and horn working, nothing else. I found that removing the battery earth lead and a 7.5 amp, instruments and relay drives, fuse (all fuses ok) and then replacing got the fuel pump to run, but no ignition and then with Robs (RatRace) help repeating the process for longer (ie battery disconnected for longer) and removing more fuses (not sure which ones) and then replacing we got the engine to crank and the immobiliser light changed from flashing to permanently on, but still no ignition/instruments etc. Switching the ignition key to 'off' put the immobiliser back to flashing (armed) mode. Replacing the ignition relay solved it. I think it was an internal failure in the relay. No water inside the car... but it was very heavy rain! Hope this helps. Peter

Hi Jim. Thanks for the tip re the barometric sensor. Think I will add a rubber tube as you suggest.. Problem fixed - fault was in the ignition relay.

Thanks everyone for all the ideas and helpful advice. Also thanks to Rob from RatRace (great guy) and Matthew and Michaela at Caterham. I ended up swapping the ignition relay around with the one above (Matthew's idea) and it all sprung into life. I was beginning to think it was an immobiliser problem ..phew! Anyone else experienced this issue with relays? Now concerned it could happen again. Thanks again. Peter

Hi Jonathan. I have just disconnected the speedometer but no change. Still stuck on 70 mph. I am wondering if the speedometer is damaged and if this could disable the ignition. Peter

HI Jonathan. Thanks - will try this. Peter

Hi Alan. Thanks for your reply. Yes I've checked that and its OK. (I even replaced it just in case). I also disconnected the speed sensor as you suggested. No change. The speedometer is stuck at 70 mph. I'm wondering how the speed sensor works. I thought it was just a magnetic pick up but can the sensor fail without blowing the fuse I wonder? Thanks for your help.

Thanks for the reply. lights, instrument lights and horn all working. Nothing else except the immobiliser. I need to borrow a multimeter for battery voltage. Nothing changes when you turn the ignition on. I have a map of the fuses and have checked them. All OK. Speedometer stuck on 70 mph. I have disconnected (and reconnected) the speed sensor but no change. I'll look at the threads you suggested. Thanks for your help.

Hi Jim Thanks for the reply. The immobiliser light just stays flashing in normal immobilise mode. No fuses blown. I'm wondering about the sped sensor. I disconnected it but nothing changed. The odd thing is that the speedometer is stuck on 70 mph. Thanks for your help.

Unfortunately I was driving along the A505 dual carriageway in my 310S (Sigma engine) in yesterday's heavy rain at 70 mph on my way back to London when the ignition suddenly died and the immobiliser came on. All rather scary. Dead car now back home with no ignition and the speedometer stuck at 70 mph. I have checked fuses and the speed sensor. All OK. has this happened to anyone and any ideas what to check next.?