1.6 Sigma 150 Quirk ??? - Final Update 23.06.09

[Windy Corner]

My Roadsport with the Sigma 150 runs well 99.5% of the time, but recently I've noticed that if you stop for 5 minutes (to buy a paper or some mik) the engine runs lumpily on the restart (to the extent it will stall if allowed)

 

Its almost as if a couple of cylinders aren't firing. After 20 seconds or so of increased (lumpy) revs, it sorts itself out,, the cylinders kick in, and runs as sweetly as ever.

 

So not a major problem, just a niggle.

 

Any ideas ?? I did think that it may be fuel evaporation due to heat, but when it is running lumpily there is a smell of petrol from the exhaust so perhaps fuel is getting though ??

 

Over to the power of Blatchat................ Thanks

 

Final Update 23.06.09

 

Please see post on 23rd June, after the latest map, Rev H, car is now fine and was had a dyno run at Northampton Motorsport. Figures are more than acceptable, so I'm happy again 😬

 

Roadsport SV 1.6 Sigma 150

in Viper Blue

 

Edit Title Updated

 

Edited by - Windy Corner on 6 Apr 2009 12:02:33

 

Edited by - Windy Corner on 23 Jun 2009 11:20:48

[shn7]

If you're smelling unburnt fuel then it sounds like not all cylinders are seeing a spark. Know nothing about the Sigma engine though.

 

Steve.

Sussex (West) AR

Not forgetting Percy the Polar Bear

[Eccles]

Hi,

 

The ECU has a sort of electronic choke that runs the engine on a richer mix/map for the first 40 seconds (ISTR). Maybe this is cutting in when it doesn't need to.

 

Regards

Ivan

[shn7]

So would that be caused by a faulty temp sensor?

 

Steve.

Sussex (West) AR

Not forgetting Percy the Polar Bear

[mav]

Probably worth dropping in to see Nick at Cat Mids and having eh ecu checked - it will also give a reading on sensors (one of which may be faulty). You should also be able t0 have the latest maps loaded into the ECU.

[Eccles]

From what I recal the 40 second thing is always there along with a gradually changing map acording to the temperature.

 

From cold, the engine starts on a cold run map (set of maps) until the engine is up to 60C, this is then gradually turned off until the engine reaches 80C when the normal running map(set of maps) is used. I have found the engine always lumpy until it reaches 80C (quite horrendously so when <50C). So I guess it could also be that the temperature is dropping just enough to put you into the warm-up region when the engine doesn't need it.

 

Out of interest Windy, does yours run really badly until it has got warm or just after the kind of stop you mention above?

 

Regards

Ivan

 

 

[Windy Corner]

Thanks for the comments, I will do some more experimentation as to the temp of the engine when it does its thing !

 

Eccles, from cold it runs absolutely fine, slightly fast idle but no lumpiness at all, it is only when stopped for 5 mins or so that it thinks about playing up.

 

Roadsport SV 1.6 Sigma 150

in Viper Blue

[h_____]

A mate with the a 1.6 sigma, has just had first service and they upgraded the ECU map, has yours had the same?

 

Assume you turn car off at ignition key, not FIA cut out?

[Windy Corner]

The car did have the latest maps when it was serviced late October prior to me collecting it, but there is apparently a new one out now !! So will talk to Nick / Jody at Midlands (thanks Mav)

 

h___ , no haven;t got a Master Switch, so always use the ignition key, although I noticed on Scoops thread, Mic said that :-

 

"When starting DONT touch the throttle as it will alter the ECU settings." which is probably something I do out of bad habits.

 

 

Roadsport SV 1.6 Sigma 150

in Viper Blue

[Windy Corner]

Okay, booked into Cat Mids in a week or so. Further investigation shows that it is lumpy for more than the 40 secs, so maybe not the mapping, current thought is the throttle body set up.

 

But of course, it won't do it now will it !!!!!!!!!!!!

 

Thanks everyone for your thoughts

 

Roadsport SV 1.6 Sigma 150

in Viper Blue

[Scoops]

Still having a cold start problem which appears to be different to yours but things have moved on a bit. I tried to do a reset as per the advice given to me but no joy. So went for a blat anyway only to lose the front passenger wing on way home 😔

 

OOO don't they fly when they let go at speed 😳

 

Anyway decided to book in at Dartford for service new wing (both to be bolted down)and ECU update early Dec.

 

Be interesting to see what it's like after the update as I always felt there was a slight flat spot at about 3.5k revs. Anyone else noticed this on a Sigma 150 or just me?

[Eccles]

Scoops,

Mine used to have the flat spot at 3500RPM but that was cured when the car was re-setup at CC using the latest map in mid Sept.

 

Is your cold start problem like mine (even after re-map), bl00dy lumpy (feeling like it is cutting-out) for the first little bit then gradually getting better until it gets up to temp? What's slightly suspicious is that it happens around 1800RPM ish, half that of the 3500 problem.

 

If so could you let me know what they find out please as, while it's livable with, it's still very annoying!!!

 

I think it is part of this cold start mapping for particular engines out there. The only trouble is you have only one shot at seeing what it is before the engine is warm and then you have to wait a several of hours before you can try again.

 

Regards

Ivan

[Scoops]

Hi Ivan,

 

The cold start was never a problem until the last few weeks. It used to be that I could the car without actually being in the car so I could let it warm up a little whilst closing the garage dopor etc. Now it immediately dies after firing unless I catch it immediately with a little throttle to hold the idle at about 1k. Within a couple of mins it's fine no lumps or bumps or stalling at junctions.

 

I'm hoping the remap will cure it along with the flat sopt.

[Eccles]

Hi,

 

Would think the re-map of the ECU and re-setting of the throttles will sort out what your experiencing.

 

Thanks

Ivan

[TobyCoulson]

I know since my car had the upgrade it has run smoother.

[Martin J]

Is it just the 150 sigma that seems to suffer from these remapping issues Mine (a humble 125) hasn't missed a beat & is very economical as well, then again perhaps I'm not giving it enough right foot

 

Edited by - Martin Jeffrey on 22 Nov 2008 16:56:35

[Eccles]

Agreed Toby, mine is really good since the upgrade, I must have a dodgy sensor or connection that is causing my cold running issue.

Not heard of anything on the 125s, getting 36Mpg with an amount of hooning, how's that compare?

 

[TobyCoulson]

My consumption improved as well after the upgrade also the surge I was getting under light throttle has more or less gone

[Windy Corner]

My 150 is doing about 34 mpg, with an element of heavy right foot, which is not too bad, will have to see if it improves after it has gone in.

 

Although, of course, since posting on here, it hasn't played up at all !!! The power of Blatchat eh ?? 😬

 

Rik

 

Roadsport SV 1.6 Sigma 150

in Viper Blue

[Martin J]

I seem to be getting in the region of 40 to 45 mpg which to be honest is very good for a high performance car! However it seems to prefer super unleaded as the engine would pink occasionally but that has stopped. Super unleaded is still a hell of a lot cheaper than diesel.

The 125 uses the standard ford injection (my sisters new 1.6 Focus looks very similar under the bonnet) this I imagine is quite *lean burn" hence the economy.

I think the 125 is a great engine with the same torque as the 150 but at lower revs.

[TobyCoulson]

I'm getting about 32mpg and I haven't been hoofing it above 6000rpm tbh 😳

[Windy Corner]

A quick update

 

Took the car to Midlands this morning, very efficient, remind myself to be nowhere near there on Saturday (!!) (hope all you Academy people have fun 😬

 

Engine map now updated (despite car being serviced by South before I collected it), was version "D" now Version "E", all temperature senders okay, car much better when cold and when warm, good as ever when hot.

 

The explanation goes something like :-

 

the new map helps cold & warm starting by reducing the fuel during the first two "phases" of the map

 

Map Phase 1 - first 40 secs, engine runs from map settings only

Map Phase 2 - up to 60 deg, engine runs from map settings only

Normal Map - over 60 degs, engine uses information from senders

 

Apologies if this is telling everyone what they already know, but I thought someone might find it interesting

 

Thanks everyone for their suggestions

 

Roadsport SV 1.6 Sigma 150

in Viper Blue here

[Windy Corner]

A further update,

 

The starting after 5 minutes problem is back as bad as ever, generally as described in the first post. Now, I know it has the latest maps, so there has to be something else.

 

It is booked in with Brett at CCM when I can get it there, but any other suggestions ??

 

I am still thinking temp sender or connection thereto, or perhaps a throttle linkage/body problem, as very occasionally I can get it to run right with a blip of the throttle.

 

Over to BC

 

Rik

 

Roadsport SV 1.6 Sigma 150

in Viper Blue here

[Eccles]

Hmmm, interesting!!

 

I've just had my map updated to the latest one and it is bl00dy awful on my engine, lumpiness, flat spots, worst between 60 and 80MPH in top (3000ish to 3500ish RPM). The cold section of the map now works like a dream, but the rest.......

 

I'd be interested to hear the outcome of your problem as it might point me in the direction of mine

 

Don't get me wrong, I'm not having a go at CC as I'm sure they test these maps thoroughly before they release them but it's making me think more and more that there is something quirky/amiss with my engine.

 

Would be grateful to hear how it goes Rik.

 

Ivan

 

 

[brianmurray325hotmail.com]

My SV 150's the same going to have a go this weekend, check all the engine earths ok set up the air flow to each cylinder (4.5kg/hr at 900 rpm i believe) using caterham approved airflow meter! then see how we go, change out each sensor, one at a time, TPS, MAP and Temp..........we'll get there