PC Pete

Well, it is fixed. I’d forgotten just how visceral that car is! Having checked sensors and wiring until there was nothing else left I tried disconnecting coil packs one by one with the engine running. It would of course struggle if the cylinder in question was firing. So when I removed the coil pack connectors on 2 and 3 and there was no difference to tick over I figured the only thing left were the spark plugs. I discounted them earlier believing that with only 3700 miles on the clock they would be fine. They weren’t. New set of NGK equivalents fitted and all is back to normal. I’ve never had a plug failure in my (long) driving career. The moral in the story is go for the cheap and easy things first!

Thanks Tazio. Yes - the first coil pack loom failed on a track day not long after I had built it- traced to a broken wire entering one of the coil pack connectors. Managed to fix it but ordered the updated loom from Caterham. Had that further updated by an F1 team(!) using silicon seal as they do with F1 cars. Never got around to fitting it until last week when the problem occurred. Have thoroughly (visually) inspected all of the connections to coil packs and injectors but all look good. Having cycled a new coil pack through each cylinder I reckon they are also good. The hunt goes on.... thanks again Petee

Thanks Jim yep - just put a new battery in it. Everything else is pretty tight although maybe I should have another look re earth connections. I suspect this could be a trial and error job with various sensors Peter

Many thanks David. I had begun to suspect it might be a sensor. Looks like I will be visiting the Caterham parts store. That said, are they different sensors to those that Ford would have used on say an Escort or Mondeo I wonder?

Ok, well, it’s been about 18 months since my 2013 R400 superlight has been on the road. It’s only done 3800 miles and tempted by the weather I thought it time to get going again. But.... on a high speed trip it felt as good as ever.... however below 2000 rpm it runs as rough as hell. Apply some throttle and you can hear a misfire. Take it on the road (ie under load) and it sounds as if it’s firing on 2! Above 2000 rpm it’s fine though. What have I done? Replaced the loom to the coil packs with Caterhams ‘’race version’ Checked all of the electrical connections for breaks Cycled a new coil pack through each cylinder Checked tightness of the air intake fixings. Full tank of premium fuel - it had about a third of ‘old’ fuel. Plugs look fine - original plugs- all light brown. It won’t idle before reaching temperature (nothing new here - Caterham couldn’t fix this either after it’s pbc). Even when it does idle the revs are not steady. So - anyone had this problem before? Would love to hear from you with your thoughts and ideas. The weather might change! Many thanks in anticipation

..... loom not look....

Thanks again Gents for help and advice. New connector to the COP? on cylinder 1 and full revs are restored. Replacement loom on order with Caterham. Further advice from an F1 engineer (responsible for the electrics integration ) means that I may well beef up the new look when it arrives. Shame it's due to rain tomorrow ......

Thanks John yep - same issue - cylinder no.1. Break in the wire to the coil pack. Well, held on by 2 strands till I got my hands on it! wasn't aware of the race loom. I'm guessing they might be expensive. Anyway - replacement connector on it's way. Tomorrow's job. Will look further at the other thread - great photos and write up. Interesting that it is a known problem. But after 2500 miles? Really? Having built three Caterhams how did I get this far without Blatchat?! Peter

Well, thanks for your thoughts on this rev problem. Given the photo above I am hoping I have found the issue. Broken wire to the coil pack on cylinder no. 1. Can't say I am impressed with the quality of what was supplied - this engine has only done 2500 miles and is less than 3 years old. new connector on order from Simtek - should arrive tomorrow. thanks again for your thoughts. peter

Thanks Martyn. £120! Life with a Caterham can be expensive.... I suspect I may be getting touch with Bookatrack if they ever return my call. thanks again Peter

Still trying to track down the reason why my 2ltr Duratec won't rev beyond 6400 all of a sudden. i have borrowed an OBD scanner - it won't read anything from my Caterham but is fine with all the other cars it has been used with. There is nothing in particular to identify the scanner I have other than 'Vgate Scan' on it. Does anyone know which scanner I need to buy that will definitely work with my car? many thanks peter

Thanks Tomiam - you are right - at least on the change up lights.

Thanks for this. I had similar thoughts myself re the Rev counter. Only thing is that the difference became clearly noticeable all of a sudden on track. It is definitely not gong as fast as it did. Agreed re the change up lights. As I said before I have little faith in how they were set up anyway - I never did get around to setting them up properly when the car was finished. So - I reckon the change up lights situation is a red herring - which means something somewhere is limiting the number of revs. There is an occasional misfire further down the rev range. This all seems to point towards a failed fuel or air sensor or a blockage in one or the other. Plugged in an OBD2 scanner but...... in common with one or two others experience - it won't read the Catetham's duratec but is happy to read any other car I plug it into! Arghhh.

Hi SM25T ​ha - great story! ...... And good point - it did happen quite suddenly so I'll take a look at the butterfly / throttle cable linkage. thanks Peter

Thanks Bizzielizzie i've always thought the change up lights were arranged to reflect what the engine was doing. I'm certain it is down on revs - on track I sometimes hit the rev limiter which I am sure is set around 7200rpm. Overall I just know that the car used to be faster at the top end. Don't know if a badly set up set of change up lights could affect engine performance. Thanks again

Not sure yet but now have my hands on an OBD2 scanner which I will deploy tomorrow..... Thanks again

Hi Jonathan good question! I will probably go as far as using an OBD11 scanner and see where that gets me. If no luck with that then off to see Bookatrack or Nick Potter. thanks Peter

Thanks Revilla strange you should mention an OBD11 scanner - was talking to someone else today who suggested likewise. This may be the time to invest in one. My thoughts revolve around the failure of some sensor or another. Cheers Peter

Cheers Tom. i'll keep an eye open for you. Mine's red with 2 white stripes - 13 plate. And yours? Peter

Thanks z7 I'm going to have a look at air flow next. Suspect it may be a sensor failure if some sort however. worth doing the easy stuff first though... thanks again peter

Hi Jules thanks for this. Nick Potter came to mind from his days at Midlands - may well give him a shout. Thanks again Peter

Ah - I thought they only arranged trackdays! Donnington is not too far away. Thanks

R400 coming up 3 years old. 2500 miles on the clock (yes - I know I should get out a bit more!) Engine has been fine following issues with start up when first built (a problem in the engine wiring loom). PH Sunday service at Silverstone last October - on track it was fine for a while but then behaved as if the rev limiter cut in at 6400. It is normally around 7200 I think. Change up lights all flashing like mad at 6400, but I have never had much faith in the way they were set up from day 1. Out for the first time this year today - same issue and absolutely consistent - 6400 revs and no more. Plugs out and look good, nothing obvious around the engine area. Anyone had the same experience? Any ideas of how to solve it? And since Caterham Midlands has closed I'm wondering where to go for servicing, bits etc.... Many thanks Peter

Many thanks for all of your replies - as speedy as ever. Apologies for not getting back earlier but I was stuck in that horrific traffic jam on the M6 yesterday for 4 hours; ironically on my way to register the car. I don't have a battery isolator switch but I agree with you Fred - it shouldn't get hot in normal operation. Strangely Caterham disagree telling me yesterday that this is normal! I can't accept this. I have pushed back on them today and await a response. On another point - has anyone experienced the engine (2 litre Duractec - brand new) hunting at tickover? Mine sits there oscillating lazily between 1000 rpm and 1500rpm. Again I await an answer from Caterham....... Thanks again for all of your responses .

Morning All Finally got my R400 back from CC Midlands after PBC and IVA. I have noticed under the dash on the drivers side what looks like a resistor that gets extremely hot whenever the ignition is switched on. It is way too hot to touch and I fear it may damage surrounding cables or worse...... As I say it is way too hot to touch. Does anyone have a similar situation? Many thanks in anticipation....