Area Representative Iain McCallum Posted June 23, 2011 Area Representative Share Posted June 23, 2011 Hi people, I am new to the forum and am in the final stages of the build of an SV Sigma 150 but am having problems getting the engine running cleanly. When I tried the first start I was a bit concerned that it didn't start easily at all then found that it wouldn't accept any throttle at all. Also it was hunting and stalling all the time. With a little help from Sean at CC we got some replacement plugs and it seemed to cure the start issues as it looks like it had flooded and the plugs were goosed. It still didn't take any throttle and so Sean sent me an engine set-up guide which pointed me at the airflow through the inlets and the TPS voltage and resetting the ECU. I am not a real mechanic so didn't have the meters and such like. However I eventually got a meter and found that the TPS voltage was set at 0.45 volts and managed to reset it to 1.03. Now the engine accepts throttle but won't idle! I am also getting a LOT of combustion in the inlets and the engine is, not surprisingly, misfiring all the time. To my untrained eye this is a timing problem which I can't fix. Any clues? Also I expected the engine to be able to run when I pressed the button as there are no instructions on having to do any sort of initial set-up on it. Is this a common 'feature' of a new build? Any help would be appreciated! Many thanks Iain Link to comment Share on other sites More sharing options...
DJ. Posted June 23, 2011 Share Posted June 23, 2011 I wouldn't think there would be any timing problems inside the engine, it is most likely that the throttle bodies aren't balanced. I've heard about problems getting the 150 to run nicely and I have read that some people have left it to the post build check. I'm afraid I just have the 125, so hopefully an expert will be along soon. Duncan Link to comment Share on other sites More sharing options...
Domus Posted June 23, 2011 Share Posted June 23, 2011 Mine ran "like a bag of spanners" I ran it up to temp to bring in the fan then left it to the post build check. Pops and bangs a bit at low revs but runs very well when "making progress" 😬 Link to comment Share on other sites More sharing options...
Pete-B Posted June 23, 2011 Share Posted June 23, 2011 Macca, I had the same problem, mind you at that time there were various map updates as well but in the end Brett at CC Midlands sorted it and now it runs a dream. Mine also had the automatic cam belt adjuster which Brett changed to a manual one. If it were me I wouldn't play with it, It should run OK out of the box, it's not your fault if it doesn't. In my case CC picked mine up from home free of charge, about a fifty mile journey for them and I collected when they'd sorted it. Good luck, by the way, the problem with mine was indeed throttle body adjustment. Link to comment Share on other sites More sharing options...
Area Representative Iain McCallum Posted June 23, 2011 Author Area Representative Share Posted June 23, 2011 Thanks for the information guys. I am tending towards getting it all checked over at the pre-build check and not running it at all before then. I presume that if there is anything major wrong it will be up to CC to fix it as it has not run at all properly yet? Pity as it sounded really good (when I could persuade it to run) when I had visitors! Really surprised (and disappointed) it comes in such a poor state of running as it is a slightly major part of the car. Link to comment Share on other sites More sharing options...
jeffi Posted June 23, 2011 Share Posted June 23, 2011 I had similar issues! Getting the throttle bodies aligned and set to the correct air flow, and then OK at idle and with the TPS voltage correct is tricky, and takes a lot of effort. I also had a dodgy ECU with he wrong map altogether, and then a duff ECU. I then had to disconnect the MAP sensor tube to match the newer ECU and open MAP sensor. When is was running bad, it was bad and undriveable, and horrendously loud with spitting and backfiring - causing stir with the neighbours. Now it's great but the map favours hasty driving and not light throttle in traffic, as you'd expect of course from a car of this type, but that could be changed with a 3rd party re-map. The best advice is said above - let CC sort in the PBC. They may need to install a new map on the ECU and balance the throttle bodies again etc. I think their quality control on the ECU form may be a little lax at times - they just ship 'em out and resolve any quirks in the PBC. Link to comment Share on other sites More sharing options...
Blacken Posted June 24, 2011 Share Posted June 24, 2011 It doesn't surprise me. When my car was a 125 I had no problems. 3 grand on it has been a series of headaches. Link to comment Share on other sites More sharing options...
Scoops Posted June 24, 2011 Share Posted June 24, 2011 Once I had the right ECU map mine's never missed a beat? Link to comment Share on other sites More sharing options...
Martin J Posted June 24, 2011 Share Posted June 24, 2011 Quoting Blacken: It doesn't surprise me. When my car was a 125 I had no problems. 3 grand on it has been a series of headaches. I've had a 125 on the road for over 13k miles over 3.5 yrs & it's never missed a beat, just a noisy diff but that has never got worse so ear plugs on a longer blat save my ears. On occasion I think I'd like a bit more poke & upgrade but I won't for 3 reasons. I don't want to upset the engine when it's running so well, I can't justify nearly £3000 for an extra 25 horses & I havn't that much dosh to hand anyway. Link to comment Share on other sites More sharing options...
diggerman Posted June 24, 2011 Share Posted June 24, 2011 It's been said by others but this is my experience. I built my 150 a year ago. On start up it did all the things you describe. I trailered it Caterham midlands and they confirmed that it had an out of date map and the throttles were not balanced. I am certain you have the same issues. The map was for the old set up that included a vacuum pipe from the inlet manifold which is no longer supplied. Once the new map was entered and the throttles balanced it ran like a fire breathing dream and has done so for 6000 miles since. Fun, fun, fun PeterC Link to comment Share on other sites More sharing options...
jeffi Posted June 25, 2011 Share Posted June 25, 2011 The trick is to not be disheartened on first fire-up of the 150 as it's more than likely to be out of balance or has the wrong ECU map which will be resolved in the PBC. Its a shame CC can't get the ECU map version correct for each model then half the issues are resolved, but I guess they just ship out ECUs with generic maps, old versions or none at all, and slap on an unbalanced throttle body onto the engine. Not an issue if you were planning on using the PBC but a hassle if you live the other side of the country and no trailer. I can say that once setup the Sigma 150 is an awesome engine on the open road. I may still re-map mine as the CC map will be biased towards track use. Then I'd have an accessible ECU with no password for me to tweak at a later date...(hmmm that could be asking for trouble!). Link to comment Share on other sites More sharing options...
jeffi Posted June 25, 2011 Share Posted June 25, 2011 oh and it would be good PR if CC managed people's expectations and warned them that the Sigma 150 is unlikely to run well or pass the IVA emissions (exhaust gases and noise) tests in it's default state... then you'd know and wouldn't worry too much. Link to comment Share on other sites More sharing options...
Area Representative Iain McCallum Posted June 27, 2011 Author Area Representative Share Posted June 27, 2011 I can understand wrong maps about a year ago, but that is a LONG time in engine management! I will let them sort it out in the PBC and post the solution. Hopeful that there is one! Link to comment Share on other sites More sharing options...
Aitch42 Posted June 28, 2011 Share Posted June 28, 2011 Hi. I had the same problem on my SV150 when I built it late last year. It fired up but ran very rough. Caterham adjusted on the post build inspection but I then took it up to Scotland for a shake down run and the mileage was terrible and it stalled every time I stopped at a junction or traffic lights. Took it in for its first service and it came out a different car - it was amazing the difference and has been great ever since. Howard Roadsport SV150 Green/Yellow Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now