ChrisC

Is it worth checking willwood to see if there is a repair kit available? I am only assuming it's a willwood because it's stamped into the cap on mine from 2016.

Caterham use a Rover sensor on a Duratec 420, well then did in 2016 and 2019 at least. MHK10006, I got a genuine one from Rimmer Bros for my cat bypass.

Idle speed is controlled by the ECU, but if the throttle stop is open too far you can get hunting at idle as the ECU struggles to maintain the idle. The strange thing is the idle speed is normally set to 950rpm. Are you sure the idle is 1050, only reason I say that is I am not sure how accurate the tacho is around idle. EasyMap (or the good work this community has done decoding the can signal) is the only true source of information.

It's used to adapt the map with the long and short term fuel trims. With a reading outside the acceptable values an assumed perfect mixture will be used, I.e no adaptation needed.

Oops https://www.thegazette.co.uk/notice/4079546

A modine oil cooler, it uses the coolant to cool the oil. It also warms the oil on initial start up, because the coolant heats up faster than the oil. Personally think it's the best form of oil cooler if a thermostat isn't fitted to the oil cooling system. Sump looks normal to me.

Caterham does sell the R gauges, they just don't list them on the website. The idea was you needed to own an R pack car to get R pack parts. Give the parts department a call or email and they will be able to help, unless you want to convert to a mechanical gauge.

Yes as far as I know, the plenum has undergone a few versions, but since we are taking about throttle bodies here it doesn't seem relevant. I would imagine they where removed from spec because the % of warranty failure didn't justify the cost. Kit builders get the full list of all parts, either fitted or to be fitted, it covers things like the sump and the cams, but no ARP rod bolts, that's how I found out.

I gave up trying to find an accurate 2011 Sigma wiring diagram when I owned an ex academy car. The one published in the build manuals (even as late as 2015) showed a MFU, which wasn't fitted to my car, and I had extra wires in the engine loom connections. That said what I had was good enough for the odd time I needed it.

I always save my old (but reusable bolts) so when I have anything zinc coated I include the bucket of bolts. Most of the time I don't get the minimum job value at the platers, so the bolts are effectively free, and they come back like new.

Oh just one point the R400 has a better engine spec compared to the 420, they ditched the ARP rod bolts on the 420 :-(

Having done the conversion from metro to CC aero before you will need the back hose. The mount holes are different and need to be drilled out. It's actually covered in the old (2015) build manual under upgrades, so it's worth checking there. Newton make the CC aero unit, so an unbranded version is available from them. Vat is charged on the service of "postage and packing", it's not just postage.

Is the car pre IVA, waiting for the process anyway? I guess the know good ECU could be used for the IVA, and a replacement sorted before registration is completed. Fingers crossed the wait isn't to long.

Totally agree, my Sigma 150 when it first came back from a Caterham Specialist after upgrade was undriveable, but I knew the reputation and had read the monster thread on blatchat so I knew the answer. The TPS and idle speed where set incorrectly. Once correct it was a honey, even pulling cleanly from 5th at 1100 rpm. The setup would wonder over time, I think due to the small springs holding the ITB screws. I would be aware of it after 6 months, and I would reset it every service. The only pain is if you have a version 1 Sigma 150, where the bleed screws are under the fuel rail, fingers crossed these don't need adjustment or it can take a fair bit of time. Version 2 resolved that problem. Finally there is various spec of quadrant (the thing the throttle cable pulls) to help drivability, but I suspect if you have an early version it's going to be very difficult to track one down now.

There is a drain hole in the heater, which will drop the water onto the scuttle.

Later models also have a fuel pump module, mounted on the boot floor, not sure what it does. I wonder if this is the reason why there is new part number.

Officially the first (1000 mile) service doesn't include an oil change, only a spanner check. That said I did one, and the diff oil.

I hope it's not a UFI filter, Caterham haven't supplied them for year. They used Fram for a bit, they now have their own brand.

I know of one new build 360R which when I saw it, pre PBC/IVA was running on all four, but had obviously been running on three at some stage. The IVA trim on the cat heat shield had melted, meaning the cat had been getting overly hot for some reason. When it went for PBC it started missing again, eventually resulting in a ECU replacement before IVA. So basically yes I have seen this before in a new build.

That's part of the reason I use LED fuses, it takes the guesswork out of the fuse setup. If the fuse is glowing it's blown. Relatively expensive in comparison to a standard fuses (about £20 per set of 18 fuses plus including postage), but the ability to stick you head under the dash and see if a fuse has blown is priceless in my book, especially at the roadside where I won't have a meter.

Wouldn't repair be a better route, that way originality and similarity with the other gauges would be maintained?

The S is on fixed platform springs, unless optioned differently. It might help if you post a picture of the problem, and what wheels you have ordered. My builds, both had adjustable platforms and 13" wheels and when they where put on the ground the clearance was hopeless, so I had to raise the ride height, by a lot :-(.

I have noticed something interesting with my 420, and this may or may not translate to the 620. Each time I isolate the battery, which I do frequently to maintain my batter health, the ECU looses it's long term trims. This wouldn't be such a problem, but the base map is rich, and the ECU lambda sensor value limits means it's ignored until a significant time / coolant temperature is reached. In my 420 case from a isolator off start I need a coolant temperature of 98c before closed loop control is engaged, compared to a start without isolation where the typical 60c / 30 seconds is all that needed before entering closed loop. Once closed loop is established the long term trims are applied and the map is adapted to obtain the correct mixture. If this is the case for a 620, the combination slow warm up in comparison to the 420 might mean a 620 would fail to achieve closed loop and therefore fail to trim / adapt the map.

The photos on the blog are either CC factory builds or my car prepared for IVA, which it pass on first presentation, before it had been to PBC. PBC was carried out post IVA, no remediation work identified. This is obviously only at that point in time, so unless it's reverted back to P clips since, tie wrap must still remain the recommended advise during build. I also prefer the P clips, but we can't recommend that for a new build.

Yes in front of the brake hose is the correct location. It always looks badly placed until it's tensioned then your find clearance for the brake lines and the rear ARB mounts. Don't fix the handbrake cable to the rear calipers unit they have been bleed and hydraulic pressure applied a few times. If you have, leave them connected, but wind the caliper back using a wind back tool. Don't touch the handbrake leaver/adjust until the hydraulic brakes have been applied.