Windy Corner Posted March 12, 2009 Author Share Posted March 12, 2009 Brian, Thanks for that, please keep us posted. Spoke to CCM just before I left for work, they have managed to reproduce but need the laptop plugged in at the same time so will keep you all updated Rik Roadsport SV 1.6 Sigma 150 in Viper Blue here Link to comment Share on other sites More sharing options...
brianmurray325hotmail.com Posted March 15, 2009 Share Posted March 15, 2009 Well, had a play yesterday, set all all choke airflows to 4.5kg/hr, only adjustable by the pair (unless severe dismantling is done and each butterfly is rotated on the "common pair" spindle), then set the TPS output volts to 1.03VDC, tickover was 900rpm. I took it out for a blast and initially lots of pops bangs and flames from the exhaust then things seemed to settle down.Ihave a fullset of new sensors 'cos i'm not convinced i've cracked it but its running a bit better.I'm out today for a decent run and i'm going to check the mpg. My main problem is at low throttle openings it was a bag of hammers and to me running extremly rich...........well see what today brings Link to comment Share on other sites More sharing options...
brianmurray325hotmail.com Posted March 15, 2009 Share Posted March 15, 2009 well the bad news is, did 136.7 miles in 24.54 litres about 25.2.gal and still running like a bag of hammers, lots of black smoke on tickover, basically in the old days we'd have said it was running on choke all the time. Begining to suspect a temperature sensor, there supposed to be 2 and i have 2 new ones but can only find one (on the inlet tract fixed to the rear of the air filter assy) but i'm not convinced thats the one thats shot, anyway we'll change it and see. I'm guessing whats happening is that the the "faulty" temperature transmitter is telling the ECU that the engine is cold and so the ECU is giving instructions to whack more juice in. If thats not the problem i'm starting to struggle, i can't belive that my ECU that was mapped on Monday last is at fault. Hope i can get it right by the switzerland trip wasn't looking forward to taking the '81 crossflow but at least i've got confidence in it..............................! Link to comment Share on other sites More sharing options...
Windy Corner Posted March 15, 2009 Author Share Posted March 15, 2009 Brian, Shame that didn't do the trick, although at least yours does it all the time 😳I will call CCM on Monday and see where mines at. Incidentally, anyone, is there a list of sensors, engine loom wiring diagrams anywhere or even a location guide showing where the sensors are ??? Thanks all Rik Roadsport SV 1.6 Sigma 150 in Viper Blue here Link to comment Share on other sites More sharing options...
brianmurray325hotmail.com Posted March 15, 2009 Share Posted March 15, 2009 forgot to add ,pre fault exposing itself mpg was 36 and a bit (now 25.2). and finally for this weekend .........i changed the temp sensor on the inlet tract (back of the air filter) and its still a bag of hammers at low revs...............meanwhile back to the crossflow for a week in royal deeside................roads just aint as good as royal teesside................don't forget mothers day next week, not many sensors getting changed next weekend Link to comment Share on other sites More sharing options...
brianmurray325hotmail.com Posted March 21, 2009 Share Posted March 21, 2009 changed out the temperature sensor today , its at the back of the cyl head you need a 20mm box spanner. CC sent me the wrong bit, dashed over to my local ford dealer and got the right bit £22, its going better and less black smoke but it still won't tootle smoothly at 1500rpm in 5th or 4th...it misses a beat.......may be its the ECU map, i'll give it arun tomorrow ....too much rugby to watch to fully check it out Link to comment Share on other sites More sharing options...
Medieval Mike Posted March 22, 2009 Share Posted March 22, 2009 Hi - this might not be relevent but I had been getting lumpy low rev performance (hunting at low speeds in traffic etc) on my 150 Sigma (new last March) and have had a succession of engine maps. I had reached the point of accepting that this is just what 150's are like as I have not driven any others until I had the first annual service (5400 miles) on Friday at the Caterham showroom. When I got the car back the mechanic (Kevin) said he wasn't happy with it and suspected the throttle sensor was faulty...being Caterham they didn't have any spares and he would have to get one sent down from Dartford. I started to drive home and the car was much worse than ever - almost undrivable and I had to ride the clutch to make any kind of smooth progress. I stopped and phoned back - Kev said he'd take one off another car for me. I told him that I was already on my second sensor (the factory had changed it back in Sept when I took the car in for it's umpteenth and latest engine map) which made him scratch his head. Two faulty sensors ? Possible I suppose... Long story...sorry...anyway, sensor didn't fix it - turned out to be the short connector cable between the sensor and the loom (plugs on each end) that was faulty and must always have been. Swapped for another one and the car is like new - correction - driving like it should always have done. Absolute pleasure to drive now and completely different. Top marks to Kev in Caterham for the diagnosis which the factory couldn't find. Hope you get yours sorted too, believe me - the 150 is incredible when it's running right. Mike Wishing I was blatting to the South of France... Link to comment Share on other sites More sharing options...
Windy Corner Posted March 22, 2009 Author Share Posted March 22, 2009 Thanks all for the contributions, my car is still at CCM (2 weeks on monday), where there appears to be much head scratching. I will feed back to CCM these points, Mike, your point sounds particularly feasible, as it is intermittent, I always surmised electrical connections may be at fault. Keep the ideas coming, I just want my car back for Wightblat !!!!!!! Rik Roadsport SV 1.6 Sigma 150 in Viper Blue here Link to comment Share on other sites More sharing options...
brianmurray325hotmail.com Posted March 23, 2009 Share Posted March 23, 2009 I changed my temoerature switch on saturday (Sigma 150), wrong part supplied by CC so got correct part from Ford dealer, no improvement!!!! still backfires, misfires and orange flames from exhaust under both acceleration and deceleration and poor running below about 2000rpm. Changed throttle position sensor (got this from CC) but no real improvement (voltage output from position sensor seemd to rise & fall ok in response to throttle operation) still poor low rev running and after ticking over for 2 mins lots of black smoke and flames at first blip off the throttle. Thats temp sensor (at rear of cyl head changed, throttle position sensor changed, airflow at each choke set to 4.5kg/hour at atmospheric pressure and temp of about 12C, still getting poor MPG. Clearly mixture is toooo rich.........fuel pouring staight through into exhaust and exploding therein..........if it was human its like a real bad attack of the Arabian Nights.................Anybody else got any further news Link to comment Share on other sites More sharing options...
Eccles Posted March 23, 2009 Share Posted March 23, 2009 Hi all, Right, lets try and quantify where I have got to (or haven't as the case maybe)... I have balanced the TBs as per the CC instruction sheet and this has made no difference. I have logged some data here to show the juddering that I am getting. I then managed to log some more data which showed the MAP sensor readings and could see that this started wobbling around before the engine RPM etc. did here so am wondering if this could be part of the problem for me. The only other thing that I have noticed is that the air temp sensor reading was more based on the temp of the air filter back-plate rather than the temp of the air around it. I don't know if this could be an issue or not but I guess that the ECU map was originally set-up with the sensor here. But, I did re-fit the sensor with an O-ring either side of it to try and insulate it a bit and when I took it out for a drive it was an amount better. According to the log it was only about 2C (26C to 24C) cooler so me thinks it was a coincidence. I've got the day off again tomorrow to have another little fiddle so any ideas of which way to go now would be greatly appreciated. First off I was going to try a new MAP sensor. Cheers Ivan Link to comment Share on other sites More sharing options...
Windy Corner Posted March 23, 2009 Author Share Posted March 23, 2009 To further add to the story on mine........... Spent an hour at CCM at lunchtime, they really have done their damndest to sort the problem so full marks for effort, after swapping everything and eliminating everything, the only thing left seemed to be the loom, so when I left they were in the process of loom inspection and possible change. I called back this afternoon, and they think they may have found the problem, a dodgy earth under the dashboard, so fingers crossed It also appears there has been another map issue, the latest is Revision F, although not sure what the differences are. I think my issues are slightly different to Ivans and Brians, in as much that mine is intermittent, when it runs well it is fantastic, but when it doesn't ☹️ I was also lucky that mine is still under warranty. Will keep you posted Rik Roadsport SV 1.6 Sigma 150 in Viper Blue here Link to comment Share on other sites More sharing options...
6speedmanual Posted March 23, 2009 Share Posted March 23, 2009 Hey Rik Sounds as if CCM may now have got to the bottom of it. Hopefully you will be able to have your car back in time for the "Grand Opening" of the Earl Shilton bypass on Friday. Peter 6SpeedManual *tongue*There's no such thing as too much BHP per Ton 😬 Link to comment Share on other sites More sharing options...
Windy Corner Posted March 24, 2009 Author Share Posted March 24, 2009 Theres always hoping, Peter !!! Rik Roadsport SV 1.6 Sigma 150 in Viper Blue here Link to comment Share on other sites More sharing options...
Martin J Posted March 24, 2009 Share Posted March 24, 2009 Blimey the Sigma 150 does seem a fussy engine Makes me glad I've got the cooking 125 which is a sweet engine using standard ford induction & single caterham throttle body. Never misses a beat Hope yours is 100% now! Martin Link to comment Share on other sites More sharing options...
Windy Corner Posted March 24, 2009 Author Share Posted March 24, 2009 I agree, it is a fussy engine, any slight problem and it coughs, although when it is right it is great. Caterham chaps said the same, all the Sigma engine problems are 150's, the 125's are fine. Seems strange when the only difference is the cams TB's and a bit of software ???? Rik Roadsport SV 1.6 Sigma 150 in Viper Blue here Link to comment Share on other sites More sharing options...
Pete-B Posted March 24, 2009 Share Posted March 24, 2009 I'm a complete ignoramous where engine tuning is concerned and my 150 as suffered all the same problems. It's been remapped at least six times and various other things. Brett at CC Midlands has been great in trying to solve the problem, he's tried adjusting the cam timing and even changed the automatic belt adjuster for a manual one because it ran better with that on. It's running a dream now when hot but still undriveable when cold and a bit lumpy round town it also pops and bangs under de-acceleration. My question is to the learned ones, surely there are lots of far more complicated highly tuned engines out there that give no problems and are a pleasure to drive. After all said and done this is basically just a tuned a Ford engine so there must someone out there who can solve it's problems so shouldn't Caterham be working towards this as part of customer relationship? But has I said at the beginning where engine tuning is concerned I'm at the bottom of the class, I would therefore like to know from the chosen ones what they think the solution to this ongoing problem is because there's a lot of us out there who aren't enjoying our not inexpensive cars as much as we should! Peter Link to comment Share on other sites More sharing options...
Windy Corner Posted March 24, 2009 Author Share Posted March 24, 2009 Well summed up 😬 Anybody 🤔 Roadsport SV 1.6 Sigma 150 in Viper Blue here Link to comment Share on other sites More sharing options...
Eccles Posted March 24, 2009 Share Posted March 24, 2009 Totally agree Peter. There must be something wrong with our cars like dodgy earths, sensors or something as there must be plenty of people who are more than happy with theirs. Maybe when all else has been eliminated they should give the ECU unlock codes to Steve at Track 'N' Road (who I hear is familiar with the MBE setup) and give us all a free RR session to set us up once and for all. I tried several new sensors today but with no improvement, I think I will head back to the earths again and re-check. Out of interest, which of you Sigma150 owners are completely happy with the running of your cars, hot running and warm-up phase? Cheers Ivan Link to comment Share on other sites More sharing options...
P150NR Posted March 25, 2009 Share Posted March 25, 2009 Ive a 2007 Sigma 150 (first SV off the line) and initially I had a bit of a problem with a flat spot at about 3000rpm when cold - when warm it was OK. I had a new map loaded at the first service and that sorted it out. Now it runs like a dream although I do try and let it warm up a bit before driving off if I can. Mal Stubbs Link to comment Share on other sites More sharing options...
Shminky Posted March 25, 2009 Share Posted March 25, 2009 I'm now happy with mine. when I first had it I had the hunting at cold which seemed to be resolved by throttle body setup. Subsequent maps have seen improvments and since the last map I had done late last year it's running like a dream. It pops and bangs on over run if you rest on the accelerator peddle - but I consider that a plus point - not a negative.... -- Shminky -- Link to comment Share on other sites More sharing options...
Windy Corner Posted March 25, 2009 Author Share Posted March 25, 2009 Picked mine up tonight, seems to run well and started again fine after being left for a few minutes. I find it difficult to believe that a dodgy earth could be responsible, especially so far from the ECU, but thats what they surmised, repaired and it seems to have worked. Need to carry out some more field testing and will report back in a few days or so. All set now for Friday (Earl Shilton Bypass Opening) and then Wightblat (touches all the wood he can find 😬 ) Rik Roadsport SV 1.6 Sigma 150 in Viper Blue here Link to comment Share on other sites More sharing options...
TobyCoulson Posted March 25, 2009 Share Posted March 25, 2009 I've had my 150 sigma for a year and have had no problems with the running of it. It does pop and bang on the over run but I quite like that. Admittedly I have done less than 1000 miles in it though so perhaps I have all these joy to come! Link to comment Share on other sites More sharing options...
BadBob Posted March 26, 2009 Share Posted March 26, 2009 Same here, with over 4000 miles done. I hired the sigma 125 before taking the plunge and found it just a bit tame, I'm glad I stumped up the extra dosh for the 150. The map that was installed in Autumn was worthwhile, improving cold running and some 'pinking' at medium loads. Link to comment Share on other sites More sharing options...
Eccles Posted March 26, 2009 Share Posted March 26, 2009 Good to hear that they do run very well, so if any of you lot wake to hear the clinking of spanners during the night, don't worry, go back to sleep, it's just the wind 😬 Link to comment Share on other sites More sharing options...
Windy Corner Posted March 26, 2009 Author Share Posted March 26, 2009 From the feedback, it sounds like the problems are limited to a few cars, the "design" would appear okay then although I have heard it said that the Single TB of the 125 is more "stable" than the 4 TB 150, so it maybe it is that, that is partly responsible. From my perspective, it sounds as though electrical connections are everything, so perhaps the next stage for Eccles and Brian is to start metering out the loom for continuity, especially connections to chassis. If you can access the ECU Live information, that may tell you that a particular sensor is or isn't working, but I have yet to do this at home yet. Rik Roadsport SV 1.6 Sigma 150 in Viper Blue here Link to comment Share on other sites More sharing options...
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