YellowPeril

At the last Rehab meet there were at least 4 cars in Caterham yellow, yours being one of them. The cars parked together all looked slightly different shades so I wonder if you may struggle to match the paint using a colour code alone. Good luck

I've had the same problem with my R300 since replacing the throttle cable. After reading your post I went to investigate further and noticed that there was quite a bit of slack in the cable, noticeable once I removed the pedal box cover. Maybe I fitted it this way, or maybe it has stretched slightly with use. Initially I thought that I would be smoother on the throttle with the slack, but in fact the opposite seems to be true. I have just removed the slack by screwing the square shaped black plastic adjuster further along the thread, and a quick trip out suggests that all is much better - the kangaroo has departed. Good luck.

Thanks for all your thoughts and suggestions Forgive my ignorance, but I am trying to think this through methodically… Air leaks have been suggested to me before: If the ECU adjusts the fuelling based on information it is sent, it must get this information from the lambda sensor? Is this correct? If so, would disconnecting the lambda sensor result in fuelling as per the map rather than adjusted to suit a reading caused by an air leak? Roller barrel throttle bodies: Yes, these can be difficult to set-up but they have been done. Perhaps they need doing again – do they typically go out of adjustment much over 12 months? Senders/sensors/wiring: These definitely need checking. The TPS has been replaced recently and may be faulty again, plus the connections to the TPS have previously failed so I could recheck this. The coolant temp sensor is a cheap part so perhaps I should just replace? Are there any others to check? To answer a couple of question: I don’t have a copy of the idle test results but I believe they were similarly as bad. The car had a good blast shortly before the emissions test, plus the test was done at length twice in the hope that we could get the temp up further.

Hi Jerry. The offer of borrowing a TPS is appreciated - I may take you up on that please. It would save me replacing it again unnecessarily

It's good to know that the CO and HC readings can be reduced significantly. The car was remapped to pass an MOT 18 months ago and all was fine. My concern is that something has changed to cause the rich running. I am open to all ideas as to what might have caused this change as unfortunately it is a 150+ mile round trip to return to Track 'n' Road to get the ECU connected up to see what might be happening. Tis a shame so few places can read an MBE ECU – if only I had an Emerald

Yesterday I had a pre-MOT emissions test. The car is an R300 (K-series, EU2) so I was not expecting great results but these seemed rather extreme : Fast idle: CO: 1.5 – 2.5% (limit is 0.02%) HC: 2000ppm (limit is 200ppm) Lambda: 0.92 (limit is 1 +/- 0.03) Within the last 18 months the car has had verniers fitted (DVA), RBTBs balanced, new plugs and TPS, compression tested (all good) and the MBE ECU has been remapped by The Two Steve’s. I have also attempted to better seal the exhaust joints as these were leaking slightly. Up until recently the car has been running really well, if still a little thirsty (26mph), but far more driveable than before the verniers & remap. I am confident that the map is good as emission readings were at the time within the limits of an MOT. The current CO and HC results suggest something has changed. Over-fuelling? The car has also recently started kangarooing badly at low speeds. I am at a loss as to where to start checking (I am not that handy with a spanner). I suppose I should check the TPS again and possibly the coolant temp sensor. I don’t want to start randomly replacing parts so is there anything else that might cause such poor emissions and is easy to check? 🤔

When I bought my 2003 car 2 years ago the handling was very precise and would have probably been great on track. However, along a typical B road the car was quite horrible to drive enthusiastically with confidence. If I went over bumps the car would frequently bounce about and aim for the ditch or oncoming traffic – not quite what you are describing but perhaps not too different. I had the tracking checked, adjusted and rechecked. I had the washers on the lower wishbones moved forwards to make the handling more predictable, but all this did was make it numb. Eventually I found someone who understood and could check for bump-steer. The steering rack had a shim or two inserted to raise/reposition it slightly and the car is a different beast altogether. Mine only has 160bhp but has done ~30k miles on Bilstein shocks that are supposedly in fine condition. I’m not sure any of this will help you at all, but it ‘may’ be something else to consider. Best of luck

I have a couple of thoughts that may help or hinder… If you can smell fuel have you noticed unusually high fuel consumption recently? Mine dropped to 12mpg at one point so I replaced the throttle position sensor - it had failed and was telling the ECU to send max fuel through the system. I seem to recall that it is a fairly inexpensive Rover part ( Good luck.

Hi If you think the wear is more on the column than the boss I would like this please - I need the boss for a second wheel. Thank you. Stephen

Thanks All. This is really helpful: http://www.carbibles.com/tyre_bible_pg4.html Seems that I might be measuring the wheels incorrectly. They have no markings so I simply measured the external width. The wheels I have might in fact be 6" or 6.5" if I measure from the internal rim so the 185s may just be fine.

Steve - thanks for the reassurance. I don't suppose you might be able to find out what width wheels they are using please? I think the 185s are fine for the car, but when enquiring about getting a couple more tyres, the tyre fitters suggested that 7" wheels might be too wide.

Hi All I am hoping someone can advise on tyre size….and yes, I have checked the search facility 😬 Originally I had 15” 10-spoke anthracite wheels with 195/45/15 CR500 tyres. I bought a second-hand set of 13” minilite style wheels and fitted Yokohama A021Rs. The 185/70/13s would not fit under the cycle wings so no cheap tyres from George Polley for me 😔 – I fitted 185/60/13s instead. From the recent Caterham autojumble I picked up a couple more minilites. Assuming my current wheels were 6” or 6.5” wide I bought two 7” wheels as I ‘thought’ I wanted to put a slightly wider tyre on the rear. I now realise that my existing minilites are 7”. So my questions… 1) Are 185s OK on 7” rims? They have seemed fine for a year but I am yet to drive the car in a more spirited manner on track. 2) Given that the original 15” wheels only had 195 tyres fitted is there any advantage to fitting 205s on the 13” rear wheels? The benefit of the 185/60/13 tyres is that they are so similar in diameter to the 195/45/15s so I can switch between the two sets without having to change ride heights or speedo calibration, plus if front and rear tyres match I can carry a legal spare when touring. I am keen to find out whether the choices are just down to preference or whether there is good reason to run one size instead of the other. The car is an R300 K-series with a fairly standard 160bhp. All help gratefully received.

*wavey*

Me too please if not too late. My exhaust is only 50cm long but am happy to buy 2m x 60cm if it helps the bulk buy.

Hi If the throttle cable is still available and will fit an R300 k-series, would you accept £28 inc p&p please? Stephen