The Pikey Posted December 10, 2007 Share Posted December 10, 2007 When my sigma 150 starts from cold it needs to warm up before the throttle is touched or it cuts out. Any ideas?? Currently, I am qualified to plead ignorance. CA08 TRM Edited by - jason fletcher on 10 Dec 2007 17:11:15 Link to comment Share on other sites More sharing options...
Old Git Posted December 10, 2007 Share Posted December 10, 2007 May be the mapping. When I first got mine, it was terrible until it warmed up, spitting & farting & cutting out, but I thought it was a case of TADTS. I realised the mapping really was out when I started trying to rev it above 5 and it wouldn't do it. CC re-mapped it, and a by product of the remapping was that the cold running was transformed. Tim N Link to comment Share on other sites More sharing options...
Steve Cornford Posted December 10, 2007 Share Posted December 10, 2007 Although I can't help with your specifuc question, a warm welcome to Blatchat Sigma Steve Link to comment Share on other sites More sharing options...
The Pikey Posted December 10, 2007 Author Share Posted December 10, 2007 Tim Its a long time since I played around with the Solex on a mates Beetle or the carb on my Escort and things have advanced a tad... So,I have been reading about this mapping thing and it seems there are compensator parameters for air temp and coolant temp etc that will have an effect on the cold running .Although I really have not got half a clue what I am doing, if I was a betting man I would say its weak on cold start. Might have to get the gear ordered and do a crash course in the black art of mapping! Steve thanks Jason Currently, I am qualified to plead ignorance. CA08 TRM Edited by - Jason Fletcher on 10 Dec 2007 20:41:00 Link to comment Share on other sites More sharing options...
Gambo Posted December 10, 2007 Share Posted December 10, 2007 I would suggest that your ECU will be locked out by caterham , to stop you remapping, thus voiding your warrantee. Sounds like a mapping issue to me( but I am no expert) I would suggest caterham take a look at it for you Shouldn't be too much of a job for them. RED 2.0 HPC 230BHP here Link to comment Share on other sites More sharing options...
The Pikey Posted December 10, 2007 Author Share Posted December 10, 2007 Gambo It's been back for the post build and they checked the map in front of me and said it was right... But I am not sure it is, and from what I can gather, no two engines are the same and a standard sigma 150 map will work in some but not all and some might need tweeking?? Does that sound right or am I reading (and writing) tripe? Jason Currently, I am qualified to plead ignorance. CA08 TRM Edited by - Jason Fletcher on 10 Dec 2007 21:24:13 Link to comment Share on other sites More sharing options...
Old Git Posted December 10, 2007 Share Posted December 10, 2007 I wouldn't have thought that individual engines needed individual mapping, but I don't know. There are basic engine parameters e.g. camshaft profiles, comp ratios etc that are fixed, and the variables such as temperature, fuel type, fuel/air ratios, rpm and ignition timing are the ones that get altered in the "map" and should work for all engines with the same fixed parameters. But I know very little about it (it's actually something I'd like to know more about) My money is still on the mapping! Tim N Link to comment Share on other sites More sharing options...
Willie. Posted December 10, 2007 Share Posted December 10, 2007 Faulty throttle position sensor? I haven't a clue about Sigmas, but have had a similar problem on a K. When you blip the throttle, does it seem as if it's got something in its throat and choke? (Sorry, best description I can think off). On the K, the TPS sits below the louvres in the bonnet, so rain runs straight into it causing it to short. I just opened mine up, dried it out and re-assembled with glue...no more problem. Worth a shot. Willie Link to comment Share on other sites More sharing options...
Mr Locust Posted December 10, 2007 Share Posted December 10, 2007 Is the ECU coolant temp sender plugged in/working. (Next to the gauge sender on a K car, can't comment on sigma.) Without that input the ECU could well substitute a default 'warm' value rather than calling up cold start mapping. Might explain if its OK once warm? Ian Green and Silver Roadsport 😬 Link to comment Share on other sites More sharing options...
The Pikey Posted December 10, 2007 Author Share Posted December 10, 2007 Willie I know the throttle position sensor is working ok because I saw it altering the injector voltage on the laptop when it was at Caterham. Ian I am not sure but I think that unlike the K series where theres two, the sigma has one temp sensor and I know that is working because I let it get up to 92 deg to check the fan comes on. Thanks for the ideas guys Jason Currently, I am qualified to plead ignorance. CA08 TRM Link to comment Share on other sites More sharing options...
The Boy Posted December 10, 2007 Share Posted December 10, 2007 Jason, How old is the Sigma. I know mine has had 3 different mappings and they are working on one as we speak . . I believe. I did have problems in the early days with poor running caused by the throttle position sensor. However I have heard people say that if the map sensor is not sealed properly this is causing fuel issues Hope this helps and is not waffle Its finally finished :-) 3500 miles completed. Back at CC now :-( Link to comment Share on other sites More sharing options...
The Pikey Posted December 10, 2007 Author Share Posted December 10, 2007 The Boy Its a whole 12 miles old, and built from a kit that is a month old. I have also heard mention of the map sensor pipe causing problems if not sealed right but as far as I can see it is. But it would be nice if Caterham fitted the same size nipple to the T.B as the map sensor has to allow a good seal both ends! I also had problems with the throttle pos sensor, it was wired up backwards.. Not a hint of waffle Jason Currently, I am qualified to plead ignorance. CA08 TRM Link to comment Share on other sites More sharing options...
The Boy Posted December 11, 2007 Share Posted December 11, 2007 Did Caterham really say that no two cars are the same with regard the ECU You say that the kit is only a month old, wow a quick biuld, well done. If that is the case then I would guess that it can't be the ECU. Does it run ok when warm? Wonder if it is just simply that the engine is still tight How have you found the car otherwise? Wait for the grin from ear to ear Its finally finished :-) 3500 miles completed. Back at CC now :-( Edited by - The Boy on 11 Dec 2007 00:12:23 Link to comment Share on other sites More sharing options...
The Pikey Posted December 11, 2007 Author Share Posted December 11, 2007 The Boy No it was not Caterham who said that no two cars are the same. I have been trawling through so many websites trying to satisfy my hunger for something new and it was one of them where I read it. It did build quick,I was hoping for an over winter project…. Next time I'll build a Robin Hood for something to do. Maybe it is because it’s new but I don’t think so.When it's warn it goes like a train. I just think with a bit more fuel at tick over when cold and the problem would not be there. But I maybe wrong. As for the kit, just very professionally done. Manual is cr@p.Some shortages as expected but I have to say that Sean at the factory is so efficient even that was not a problem. Jason Currently, I am qualified to plead ignorance. CA08 TRM Edited by - Jason Fletcher on 11 Dec 2007 00:45:28 Link to comment Share on other sites More sharing options...
Eccles Posted December 11, 2007 Share Posted December 11, 2007 Hi Jason, My car does the same, the something getting caught in the throat analogy is spot on. I have had a look at my TPS and it reads 1V at tickover and 4.3V at WOT but I am not sure if this is correct. Hopefully I have a couple of USB to CANBus interfaces on their way to me at the moment so I hope to be able to connect it to the ECU and use Easymap to look at the settings. Can't change anything in the map but it will be good to monitor what is going on. Regards Ivan Link to comment Share on other sites More sharing options...
Dickie Normuss Posted December 11, 2007 Share Posted December 11, 2007 Ivan, when do we get to see it at the meet? VX HPC - Loud and proud here Watch out, whatever hits the fan will not be distributed evenly Link to comment Share on other sites More sharing options...
Eccles Posted December 11, 2007 Share Posted December 11, 2007 Soon, it's all been conspiring against me at the moment. I was planning on bringing it to the November as SWMBO was going to be in hospital but she was sent home earlier than expected late on Tuesday afternoon so I thought I should stay at home and look after her instead 😳 😬. Ivan Link to comment Share on other sites More sharing options...
Eccles Posted December 14, 2007 Share Posted December 14, 2007 I sealed the joint properly for the MAP sensor earlier and took it out for a drive today and I'm sure it was a lot more responsive and didn't have anywhere neer the same problems when reving the engine. Maybe worth a look if you are still having problems. Ivan Link to comment Share on other sites More sharing options...
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