Fired her up for the first time.....doesn't sound right!

[Alexander Gurr]

Just fired the car up for the first time and she sounds as though she is running on 2 - 3 cylinders. I have checked all of the wiring and it looks OK. Is this normal and does it just take time sort itself out, or is it likely that there is a problem of some sort?

 

Cheers,

 

Alex

[Eugene]

Hi Alex, I'd say not normal, but probably not a major problem.

 

Check fuel as well as electrics.

 

Probably something very simple 😬

[Alexander Gurr]

Thanks Eugene.

 

I put 20 litres of fuel in this afternoon, so can't be that. All of the visible connections look firm. There is smoke coming from the exhaust and when I first turned her over she backfired and stopped after a few seconds. Since then she fires up OK, but seems to be running on 3 cylinders. There is also smoke coming from the exhaust primaries, but I thought that might just something burning off. I guess I need somehow to work out if it is fuel or spark

[Eugene]

Burn-off smoke is normal after a build - grease on exhaust, etc...

 

Are all injectors working ok?

 

It's unlikely to be ignition map, as that would cause general rough running.

[Shad]

Mine tends to do this only if one of the HT leads isn't seated fully (or has worn out/failed), but then again mine's a K so sometimes does special things just for fun 😬

[Martin J]

Is the oil pressure where it should be? I'm sure that would be the first thing you would look at!

re poor running.....is one exhaust primary cold? Difficult to tell I know without burning yourself. Pop the engine cover off & check all plug leads are secure etc. If it's persistent you may need to unscrew the plugs & look at the condition, any sooting or fowling & check gaps etc.

I have to say you are romping through the build, it took me a lot longer!

[Alexander Gurr]

I just checked all of the leads and plugs and they were fine. I then went through the recommended start procedure.....taking out the connection from the inertia switch and cranking the car over to get oil pressure. The strange thing is she fired up perfectly, which makes me think that I have the wrong connection to the inertia switch (two green and yellow wires to a three pin female plug), because I assumed with this disconnected it shouldn't be able to fire? Or does it cut the fuel pump and the car will run for a few seconds until the fuel line is dry?

 

Anyway I reconnected the inertia switch connection and she fired again and ran sweetly at 1,500rpm, before starting to settle down towards 1,000rpm. One other thing that worries me though is that it was reading virtually zero oil pressure. I know the system is full and switched off after a few seconds, but how do I make sure I have sufficient oil pressure as I really don't want to do any damage to her at this stage.

 

Cheers,

 

Alex

[Stationary M25 Traveller]

The inertia switch cuts the fuel pump, so it would only run for a second or two.

[diggerman]

I had same prob with my Sigma 150 when I first started it18 months ago. The problem was that the ECU was wrongly mapped. Caterham were very relaxed about this. They instructed me to complete the build and they would sort the map at the post build check. After 5 mins on the Cterham mids laptop all was fine. I know of others who have also experienced this.

 

Am a bit more puzzled by you comment on oil pressure. You should crank the engine with no ignition for as long as it takes for the oil pressure to rise. This may take 20 plus seconds. Do this in several bursts with a good gap in between so that you don't stress either the starter motor or the battery. Once all the oil chambers and the oil filter are full of oil the pressure should go up quite suddenly to normal working pressure. At this stage top up the oil level and then when you reset the cut off switch the engine should fire up and full oil pressure be obtained straight away.

 

If in doubt leave the start up to the Caterham checkers.

 

Don't worry about it ..... All will be well!

 

 

PeterC

[DJ.]

This may not be the same as your car, but ever since I built my Sigma 125 the oil gauge goes to zero for a couple of seconds on start up and then returns to normal.

 

I have fitted an oil light and that goes off immediately the engine starts and stays off when the gauge is reading zero, so the engine is fine.

 

I have no idea why it does this but it isn't a problem and I sort of assumed they all do it

 

Duncan

[Martin J]

Relax Duncan.....mine does the same

I think the gauge or at least the sender is pretty accurate on the sigma. I changed the oil & filter on mine in the week. On the first start up following, the OPG took perhaps 3secs longer to rise & then settle at a steady reading than normal. This would correspond with the empty filter filling for the first time.