aerobod - near CYYC

Supposedly Toyo mark the lightest point of a tyre with a yellow dot, which should be aligned with the valve stem. Other manufacturers may use different colours with different notations. A red dot is also common. If two dots appear on the sidewall, usually one is the lightest/heaviest point and the other the highest/lowest point. Here is a more detailed explanation of match mounting from Yokohama: https://www.yokohamatire.com/tires-101/advanced-information/match-mounting

If it is the left or right drive shaft seals leaking, it is important that the seals have been inserted only flush with the face of the casting and no further, as they seal only about 2 or 3mm on to the shaft shoulder. Also it should be checked that the springs in the CV joints are fully pushing the shafts in to the diff, if the diff is off centre this may not be the case, causing a leak on the side that the diff is furthest away from.

It might be worth trying Demon Tweeks for the 8x13 anthracite wheels, I bought a set from them in 2014 when Caterham was out of stock: http://www.demon-tweeks.co.uk/motorsport/wheels-tyres/caterham-r500-8-spoke-wheel

I looked at pulling the switch element off the back of my start push button, but it is a bit risky that the locking tabs that hold the push button to the switch element could break instead of releasing. Two largish zip ties with the tips cut off were a good fit into the rectangular holes in the back of the switch element, just push them in to ease the locking tabs open and allow the switch element to be pulled off the push button with little force.

Thanks Mark & Dr Slotter, I will print off a copy for my 2012 R400D. - James

Sorry Paul, got my currents and raisins mixed up! Should of course be tens of milliamps of stray ground current, caused by the tens of millivolts of ground voltage.

I only ever run the laptop on battery power when data logging in the car. In the hostile automotive electrical environment you will always see tens of milliamps of stray ground voltage which you want to avoid being fed through the USB connection. An isolator may prevent this but may not be sensitive enough to prevent damage to standard computer logic circuits.

Hi John, Was your 9A4 ECU supplied by Caterham, or by an MBE supplier such as SBD? If from Caterham, it is definitely locked and won't accept unlock codes (seems to be directly flash updated by some proprietary method, as opposed to by Easimap). If supplied by someone other than Caterham as an aftermarket ECU, then it should accept unlock codes, I would go back to the supplier / tuner if that is the case to get the code. You can also change the access level within Easimap, if you haven't already found this feature - in the bottom right of the screen if it says "Profile: Basic Level 1", click on the text and select "Advanced Level 1", this will give you a wider range of access. - James.

Hi John, Paul's list is a pretty good one, I would add: Final injection time Coolant, air temp, manifold and baro fuel factors / compensation percentages Lambda status Typically between 20 and 30 parameters should be able to be logged at the same time. You will only be able to show map and other tunable parameters with an unlocked ECU (such as the 9A4). The standard ECUs (such as the 992) are encrypted, so output values can be displayed but ECU settings can't be changed or displayed. A couple of other things to bear in mind are that if you have multiple pages open, switching page will lose any logged data to that point if you haven't saved it to a file, avoid ground loops that could cause damage to the electronics by making sure your laptop is only connected to the USB cable and not to power via an inverter or 12V socket. - James.

You could go to somewhere like this: http://metalsupermarkets.co.uk/metals/aluminium/ . If they are the same as the Metal Supermarkets in Canada, they will cut you pieces any length you want, so you could buy 4" / 100mm X 1.5" / 38mm 6061 aluminium alloy angle or something close to that and have them cut a couple of pieces off for a few £.

Looks like the layout changed between 2008 and 2010, as my 2012 standard dash R400D also has the 18 fuses and 6 relays that don't match the handbook wiring diagram.

I find mine is quite finicky in where it is held, but I find it is reliable if I hold the transponder near to the security system status LED at the back of the tunnel tray. I normally lean over the car before getting in, press the start button to power on, wave the transponder near the LED until it goes from flashing to solidly lit, press the start button to start the engine, then get in the car.

On the R400D with keyless ignition, the engine will keep running without the transponder until the "start" button is pressed to shut the engine off, the security system will then re-arm 20 seconds after that. The transponder will then be required to be brought back into range to start the engine again. The transponder is basically required for engine start, but not for running.

I would say inside the switch or relay there could be a broken component, also worth checking there is no short or touching spade connections between the wiring on the back of the switch. It looks as though 2 relays are involved with the hazards / indicators, as shown on the wiring diagram, by correlating the connection numbers:

I would say a loose contact or broken spring would be the most likely cause.

slap_ed, my R400D also has a variable sweep that sometimes leaves the needles not at zero when power is switched off. I don't think there is an issue, just seems to be how much momentary power is applied to the instruments and whether they manage to complete a full test sweep before the power is removed. ScottR400D, In terms of the hazard lights not working, if it is not the relay, it could be the switch element itself. The R400D switches are both a work of precision engineering and a nightmare all at the same time. They are completely modular, expensive and finely engineered. The button, bezel, mounting and switch element are all separate and are from the EAO 61-series of switches. (Here is the relevant catalog from EAO, the switch element start on p651! http://eao.com/fileadmin/documents/PDFs/en/01_main-catalogue/EAO_MC_61_Main-Catalogue_EN.pdf). If the switch element has gone bad, you either need the special removal tool or 2 medium sized tie-wraps to insert into the 2 rectangular slot on the back of the switch, you then press into the slots to pop the switch element off. I had to do this to replace my "start" switch button, that is when I appreciated both the elegance and nightmare these switches present! In the UK Farnell is probably the best source of parts for this switch, if you have to take it off, you can examine the switch element and determine which part number it is for replacement.

Glad it is all working well now! Your fluctuating idle is normal when the throttle site is in the 1 range as opposed to 0. I found Caterham had done the same thing on my plenum R400D, perhaps to allow for manufacturing tolerances. When I replaced my ECU with an unlocked one, I reset the throttle limits to make sure I was at 0.0 to 0.2 at idle. When at site 1 the map is trying to add fuel, but as you don't have enough air with the throttle closed, it will go rich, the lambda sensor will then detect the rich mixture and the ECU will then trim the fuel down again. The slight oscillation tends to be in tune with the lambda cycling. Adjusting the rotation of the TPS or adjusting the throttle stop may eliminate this, but make sure at full throttle you still get well into TPS site 14.

I think it is a bad lambda sensor or a problem with the wiring between it and the ECU (although your continuity and voltage tests seem to show the wiring is OK). The oxygen raw voltage at initial start with a cold sensor starts at 5V as expected until the sensor heats up. It is interesting that the oxygen raw voltage flatlines at 0V a couple of times, indicating a potential intermittent wiring or total sensor output failure issue, but when it isn't zero, it tends to 0.25V or so once warmed up. At the 6 minute mark when the coolant hits 60C, the lambda status changes to "OK", then within 3 seconds the adaptive fuel starts increasing until it hits about 70% extra fuel at the 8 minute mark, when the engine stalls, after engine restart the adaptive fuel is back at 0% for 45 seconds while the lambda status is "warm up", then quickly starts to increase again. The way the adaptive fuel increases is consistent with the perceived lambda status and continued lean reading. i checked the narrow band lambda sensor part number from my car and it is the same as yours (Bosch 0258 003 229), the heater element resistance on mine is 3.3 ohms across the two white wires. The black wire on the sensor should connect to pin 29 on the ECU (blue/brown wire), the grey wire to pin 5/23/24 (brown/black wire) and the two white wires will use pin 13 and pin 6/7 (black/yellow and green/orange wires). One thing I also thought about, is your lambda sensor in the standard position just after the 4 into 1 transition in the exhaust but before the catalyst (if fitted)? Also, if you have a catalyst fitted, have your checked that there is no obstruction in it or the rest of the exhaust system? As someone else mentioned, an exhaust leak can be problematic, I used high temperature copper silicone sealant to remove some small leaks where my 4 into 1 pipe joins to the header pipes and the silencer (I don't have a catalyst). The leaks were indicated by some soot near the pipe connections.

Hi Tomiam, I could only open your first log, as I couldn't see the matching LSN file for the second log. In the first trace though, your lambda values are not oscillating correctly when short term lambda status is OK. The oxygen sensor voltage stays around 0.25V, but should oscillate around 0.5V, as in this diagram: http://n.b5z.net/i/u/6137562/i/narrow_band_o2_voltage_graph.jpg This could be caused by a number of factors, but if all the plugs are evenly black I would rule out fuel injector problems for over fuelling. As the target lambda is 1.00 (that correlates with a narrow band oxygen sensor voltage of approximately 0.5V), a lambda value above 1.00 tells the ECU that the engine is running lean, so trim fuel is added to try and push the engine to a lambda value below 1.00, but that would require the oxygen sensor output to reach a voltage higher than 0.5V, which it doesn't seem to do. As you have replaced the oxygen sensor, I would look carefully at the supply voltage, to see if it is high enough to operate the sensor properly, if possible back probing the sensor connector on the sensor wiring side. The black/yellow wire on the loom side of the connector is the power ground, the green/orange wire is the 12V supply, the blue/brown wire is the oxygen sensor output to the ECU and the brown/black wire is the signal ground to the ECU. The issue may be bad power or signal grounds or a ground loop between the sensor and the ECU. It is also worth checking the resistance from the ECU 36 pin connector to each of the oxygen sensor leads. Pins 5, 23 & 24 on the connector are signal grounds, pins 6 & 7 are power grounds, pin 13 is 12V switched supply and pin 29 is the oxygen sensor signal. The resistance with the battery disconnected should certainly be less than 1 ohm between a given pin on the ECU connector and the matching connection on the oxygen sensor, preferably close to 0.1 ohm. Here is the ECU connector pinout (the 992 and 9A4 ECUs use the same pinout: http://www.sbdev.co.uk/Info_sheets/MBE/9A4-PinoutIssue%20F.pdf Just an observation on the throttle site and TPS voltage, site 1.1 being the minimum may cause an oscillating idle, depending on how the map was written. Adjusting the TPS rotation if possible or closing the throttle idle stop could get you into the 0 to 0.5 range. Normally the throttle site would either be interpolated between adjacent maps or adjusted to the closest map, in this case maps 0 and 1 are relevant. Map 0 would normally be optimized for idle parameters, but map 1 would have parameters more appropriate for non-idle conditions. The TPS voltage seems to decrease with throttle opening, this is a Cosworth TPS configuration. According to SBD, Cosworth accidentally switched their TPS wiring many years ago and have not followed the convention of low voltage being low throttle ever since. The R400D with plenum uses the conventional low TPS voltage equals low throttle opening, but the MBE ECUs can be setup to handle either increasing or decreasing TPS voltage with throttle opening.

Hi Tomiam, to get used to the software and understand the sensor outputs, it is worth starting the car and running it up to temperature while the car is stationary, you could then run your laptop while plugged into the mains. While on the 2nd page, which should have about 25 panels displayed, look at the sensor values. All the temperature sensors should start out pretty close to ambient if the engine is cold and then steadily increase as the car warms to operating temperature. When fully warmed up your water temp should be over 80C and the fan should come on in the 90C to 100C range. Your air temp will be somewhat warmer than ambient when the engine is warm (will be dependent on heat soak and air flow around the filter), but will reach a stable value while the car is stationary. With the car on but not running the TPS voltage should increase and decrease smoothly over the whole throttle range (I have the plenum intake not the throttle bodies, with my TPS voltage from 1.35V at idle to 4.75V at full throttle, which may not be the same for you). Throttle sites should also smoothly change from below 0.5 at closed throttle to over 14.5 at full throttle. The battery voltage should be in the range of about 13.2 to 14.2V with the engine running at 2000RPM, but I have seen on my R400D that it can drop to about 12V at idle with the radiator fan on. I originally saw about 0.4V of noise in the battery voltage signal, but added some extra grounds to get this down to about 0.2V. The lambda sensor short term control status will start at either "bad AFR", "waiting for timer" or " coolant temp too low". By the time the coolant temp gets above 60C and it is not in a "waiting for timer" state it should change to "all conditions OK" and you should then see the lambda data oscillate between about 0.8 and 1.2 between about once a second and once every 3 seconds under gentle throttle openings. Under aggressive throttle changes and/or high engine speeds you should see a lambda status of either "disabled by target map" or "TPS unstable" At idle your throttle site should be between 0.0 and 0.5, the ignition advance will bounce around a bit from small positive to small negative values and your fuel final injection time when the engine is warm should be about 3ms per cycle, with the duty cycle under about 5%. If you have the MAP sensor beyond one of the throttle bodies it should read (assuming close to sea level) 1.0 bar with the engine off, about 0.5 bar at idle, 0.2 bar when the throttle is closed quickly and 0.7 to 1.0 bar under acceleration. If the MAP sensor is before the throttle bodies, then is should just indicate atmospheric pressure at about 1.0 bar and not vary within throttle settings. If all of the above look good, it is time to take the car for a drive to log data!

The typical behaviour when the lambda sensor is disconnected is to drop to open loop mode due to an implausible lambda value (not in the range of 0.5 to 1.5), the values for fuel would then be based on engine load, coolant and air temps, etc, as is the case during engine warm up. A few tips from my experience, when using the cable and Easimap (please ignore anything which is SBO - Stating the Bleeding Obvious!): - follow the install instructions carefully - be careful getting in and out of the car while the adapter is connected under the dash, it is rather in the way of your knee. Use some Velcro or tape to keep the cable out of the way of your legs or car controls - make sure you easily have enough battery run time in the PC to capture a whole session, PC shutdown during logging will lose all data - save logged data to a file before switching screens using the page up / down function - don't use an inverter powered from the car's battery or power from the 12V socket in the car to power the laptop (this is a tip for any vehicle), as there is a high risk that a ground loop would be created through the mapping cable to the laptop with a risk of signal noise or even damage to the electronics - don't try to add too many panels (sensor displays) to a screen, 30 seems to be a good number (I tried to log every conceivable sensor at the same time, it didn't seem to work very well and many values that can be logged are useless or just a different processed value of the raw sensor anyway. From what I remember there are 3 default install pages, the second page is the best starting point for default sensor panels. - have a driving strategy for collecting data and plan a suitable route before starting the logging, don't be tempted to view the data while driving (take a passenger to do that if you want to correlate poor running while viewing parameters in real time) - monitor all the way from engine start to engine stop through warm up to avoid losing any useful info - it is sometimes worthwhile checking all the idle values while the car is parked, but running - is any value fluctuating strangely, is the TPS value correct, are the temperature sensors giving expected values, etc? Once you have a data log, we can go through how to filter and review the results to home in on the problem, if it isn't immediately obvious to you or your mechanic. Good luck!

Unless the auto electrician deals with MBE ECUs (certain TVRs, Nobles and Caterhams being the main vehicles using them), he is probably thinking a generic OBD2 analysis system would work. The generic system cable would certainly fit as Caterham has fitted a compatible connector, but they don't use OBD2 messages, only very basic CANbus messages that have to be interpreted by the MBE Easimap software, which a generic system would not be designed to do. If you get the cable, you will be able to drive the car around while the problem is occurring and log the data from the sensors (I usually put the laptop on the passenger seat and hold it in place with the harness over the screen). If you can't interpret the results yourself, there are probably ten people or more on Blatchat who have enough experience to have a look at your data and see what should be checked. We would be looking for things such as the lambda sensor warming up correctly then oscillating at the correct voltage levels, sudden changes in sensor or fuel injector values while the engine revs and throttle position is steady, etc. SBD should be able to help you confirm over the phone or via email that there is no issue with cable compatibility and that you already have the CAN-H and CAN-L wires in place in your car that will be used by the MBE cable and adapter to connect to a USB port on your laptop.

Your MAP sensor could be the problem, but it should cause issues at all revs, not just below 4000RPM. You can test to see if the MAP is sending a reasonable signal to the ECU by holding the revs at somewhere between idle and 3000RPM while the car is stationary, then unplug the electrical connector on the MAP sensor, the engine should then just die if it had previously been sending a plausible signal. I would really encourage you to get the MBE cable and the Easimap software, you and any mechanic without it are really very much in the dark without being able to see all the sensor outputs at the same time to diagnose the problems. I would offer a loan of mine, but the return courier charges between Western Canada and the UK would cost about the same as the cable is worth (Easimap is free to use and can be installed on any Windows PC). You need the MBE-MAP-KIT-3-CAN, which is £120 inc VAT from SBD Motorsports: http://www.sbdev.co.uk/Engine_Management_Systems/ECU/Programming.htm

Hi Tomiam, From an ECU perspective I would check all your grounding and continuity between your ECU plug and the sensor end of the wires using a multimeter, anything higher than 0.5 of an Ohm would be suspect. I would also confirm that the voltage from the grounding terminal on your fuse block to the battery negative and to the engine block is as low as possible while the engine is running (10 millivolts or less is ideal). If all your grounds and sensor cables are good, it is best to borrow or buy the MBE canbus cable to hook up to a laptop to look at what is happening on the road. It is best to have someone driver the car while you give them instructions on what to do while looking at throttle voltage, lambda setting etc. Better still to take someone who understands engine tuning. You can also save the data logs for analysis once home. Making sure the throttle as at the right throttle site for a given acceleration, lambda values are correct in steady running and all your sensors are giving realistic values will enable you to home in on the problem. It really is worth the £100 cost for the MBE cable, if you don't already have it.

I think good grounding helped a little, but the pin swap would use the cleaner logic 0V reference as opposed to the chassis ground, so if the chassis ground is also quite clean it shouldn't make a difference. What I have noticed is a lack of short ECU resets compared with before re-pinning and adding better grounding. These resets typically seem to be about 20 milliseconds and increment the ECU reset counter, they appear as an occasional spike in ECU parameters, which seemed to cause a slight stumble, although they would only occur a couple of times per hour. Just a general attention to the best possible grounding, best use of the available pins, using some extra cable ties to make sure cables are well routed and secured have I think left me with better consistency between the sensors and ECU. The car is now much more predictable in the way the engine performs than when it left the factory just under 20,000km ago.