Rich_tea

Thanks all. I'll try the repositioning suggestion before I cut off the extension.

The throttle pedal arm on my 2.0 Duratec with RBTBs has been extended by a couple of inches or so to increase the cable travel but I'm not sure why. I'm wondering if the RBTBs need more cable travel? The car has a tendency to kangaroo at light throttle in low gears and I'm thinking the increased pedal ratio/sensitivity could be the cause or at least a contributory factor.

Thanks both. 7 Wonders, is the tank from Raceline? Also, how would you improve the plumbing - presumably using braided hoses with swaged fittings rather than Jubilee clips? Why would a circular tank be better?

I've now had a chance to get underneath. The sump itself appears to be the Duratec item listed on Caterham Cars website. My main reason for wanting to understand which tank I have is so I can establish the correct oil change procedure.

My 2005 SV apparently started life with a 2.3 motor but the original owner rebuilt the car in 2015 with a 2.0 Duratec motor in 420R spec. I can't identify the type of oil tank in the car as it is different from others I've seen on the internet so any advice would be welcome. Hopefully the picture is clear enough but it's mounted on the left rear side of the engine compartment beneath the air filter (removed for clarity).

Thanks for the offer James. PM sent.

Thanks James, I've sorted the ECU connector. Before adjustment, the closed throttle front 2 cylinder throttle openings were around 5.7 mm and rear 2 around 6.8 mm. I balanced them to bring the fronts to match the rears then lowered the idle stop to bring all 4 to around 6mm. I adjusted Throttle Angle 1 (TPS) from 4.59V @ closed throttle to 4.62V. Throttle Site 1 was reading 0.00 (not flashing) before and after TPS adjustment at closed throttle. I ran the engine up to temp and did an Easimap logging session. I don't yet have a flow meter so couldn't measure or balance air flow. Normal idle when warm was 1000 rpm with small fluctuation. I did a couple of fast idles approx 2500 - 3000 rpm and a blip to about 4500 rpm then back to normal idle and shut down. Throttle Angle 1 and Throttle Site 1 seem to change with throttle input, lowest Throttle Angle was about 4.24V and Throttle Site max was about 6.1 at the 4500 rpm blip. The car has always had a tendency to kangaroo at slow speed light throttle openings but not sure if this could be linked to the RBTB imbalance? The only apparent anomaly I can see in the log file graph is Lambda, which fluctuated around 0.65 and only spiked momentarily to about 1.1 when I dropped the throttle back to normal idle. Lambda Status was displaying "Control Disabled by User" at normal idle and "Control Disabled by Target Map at fast idle & throttle blip in the Easimap live Panel but only showed a flat line "Disabled by User" in the entire log session graph. Today's Lambda reading was using the new Bosch Lambda sensor but was consistent with the log data I got the older day using the old Lambda sensor and before adjusting RBTB balance & TPS. The Lambda reading around 0.65 seems off the scale from what I can find on a quick Google. When I measured the Lambda signal voltage in March with a voltmeter before getting the Easimap interface (details in an earlier post), the voltages I recorded then appeared to be closer to spec than the 0.65 Lambda figure now suggests (noting Lambda value in Easimap is not voltage). I still have not changed the fuel which is now over a year old so that's on the list. I may also put the old Lambda sensor back in and read the voltage again to see if the RBTB/TPS adjustments have made any difference. There are no obvious air/exhaust leaks so any other advice/suggestions would be most welcome. The car is SORN and out of MOT so I can't road test it (legally) unless I'm taking it for the MOT. If anyone is willing to look at my Easimap log file, that would be much appreciated.

Thanks James and JV. Unfortunately when I went to run Easimap again, it isn't seeing the ECU this time. After I ran the first logging session, I disconnected the ECU connector to test continuity on some feeds but I think when I reconnected it I must have dislodged the female socket in the loom connector for Pin 8 (CANL) (clear plastic shroud removed for investigation). Any tips on getting it back into position? Looks like I need to open the backshell casing and push it back into position from the rear?

Thanks for the input James. I had a feeling it wasn't as simple as a faulty MAP sensor! This is the physical setup: So I can see how the MAP sensor is effectively redundant given it's location means it is probably not going to see any significant pressure change. Any idea why it's even installed? Coolant temp sensing appears ok and I've replaced the Lambda sensor with a new Bosch MHK 10006. Which other sensors do I need to check and can you give me any pointers to info on checking the RBTB balance and TPS alignment? I haven't yet changed the fuel either which is now over a year old. I couldn't siphon the last 9 litres so assume I'll need to disconnect the fuel line from the filter and pump it out, if that is a possible cause of the rich running.

I've not had a chance to investigate the emissions issue further until now so the car has sat in the garage since the MOT failure and our initial attempts to diagnose the problem back in March. I have bought the MBE ECU CAN diagnostic interface and have done my first logging attempt using Easimap 6 software. After letting the car warm up for 10 minutes, Lambda is running very low (rich mixture) at between 0.5 - 0.8, whether at normal idle or fast idle (2500 - 3000 rpm). However, "Manifold Pressure 1" which I assume is MAP does not change during the logging session from 1.021 Bar. So it seems the MAP sensor is duff/broken wire etc, unless anyone has any better ideas? Thanks.

Thanks for the replies guys. The actual numbers were: Fast Idle Test: CO 3.09 / HC 85 /Lambda 0.921 (limits are 0.30 / 200 / 0.950-1.090) 2nd Fast Idle Test: CO 4.32 / HC 166 / Lambda 0.882 Natural Idle Test: CO 2.70 (limit 0.50) So the main issue is high CO and low Lambda, indicating a rich mixture. The car has done 500 miles since last MOT and about 2K since effectively new. Any info on checking the RBTB balance would be welcome. I checked continuity from the temp sensor to the ECU but measured its resistance at the sensor itself. The car was warm (both coolant and oil) for the MOT and our home diagnosis and the replacement lambda sensor was a genuine Bosch. The fuel (BP Super Unleaded) is probably at least 8 months old. Is this a possible cause and if so, how does it cause a rich mixture?

Hi, my 420R spec Duratec engined car failed the MOT on emissions. CO was high, lambda was low on all tests. I replaced the lambda sensor which made no difference. Looking back at previous MOTs over the last 5 years I've owned the car (total miles only about 2K in that time), all at the same MOT station, the 1st Fast Idle has always been similar but 2nd Fast Idle has been ok. Since build the car has just under 5K miles. The car is running RBTBs and an MBE 992 ECU (Caterham supplied). From internet research, the high CO and low lambda readings suggest it's running rich. So I've checked the coolant temperature sensor for the ECU and that appears fine (66 KOhms cold, just over 2 KOhms with the Stack Dash reading around 90C). I put the old lambda sensor back in, with a cable spliced into the signal wire to allow me to read the lambda signal voltage. Once warmed up at normal idle, it cycles in the 0.2-0.8V range which is apparently normal but above normal idle (tested between 2-3K RPM), the lambda voltage goes to about 0.9V and stays there, which apparently suggests rich running. Once it's back to normal idle, it starts to cycle again in the 0.2-0.8V range after it settles down. The car hasn't been used since about July and was taken straight from winter hibernation to the MOT, but via a long route with some motorway miles as well to make sure it was thoroughly warmed up. It seems to drive ok. Any advice would be appreciated.

Full set of 6" front 8" rears with or without tyres, black centers. Cheers, Rich

Hi Martyn I'll take the half hood please. Rich