Matt230 Posted November 8, 2018 Share Posted November 8, 2018 Hi allFirst post after returning to Caterham ownership.One slight issue with the recently purchased 7 which has only showed itself since its been colder. When the 7 is cold it revs out between gearchanges and in gear when lifting off the throttle feels like its running on for a few seconds. When warm there is no issue. Car is a 1.8, with Emerald, roller barrel throttle bodies, forged pistons, verniers, uprated cams.Recently had it rolling roaded and a bit more fuel put in at the top end.but produced a healthy 193bhp with filter on. Wasn't aware of this cold issue as was warmer when taken over there. Assume it mapping as if the rollers were sticking surely this would happen when warm too? IACV?ThanksMatt Link to comment Share on other sites More sharing options...
Alan Reeves Posted November 8, 2018 Share Posted November 8, 2018 I recently had a re map and it was done with a still warm engine. It would not tick over on start up until it was warm. Went back and modified the map.they like to do a map session with a cold engine ...apologies for strange words etc, predictive stuff and fat fingers...dont i ever learn to check it.... Link to comment Share on other sites More sharing options...
ScottR400D Posted November 9, 2018 Share Posted November 9, 2018 Sticking throttle cable when cold? Link to comment Share on other sites More sharing options...
Matt230 Posted November 9, 2018 Author Share Posted November 9, 2018 The other point is that i did disconnect the battery briefly to fit the battery conditioner.Would the throttle cable stick when cold but not warm? one to check but im not sure how the cable works on the roller barrel, ill try and have a poke around later todayReally pleased with the car, cant wait to get it on the track!Matt Link to comment Share on other sites More sharing options...
Wrightpayne Posted November 9, 2018 Share Posted November 9, 2018 Not sure if the same with an emerald, on standard K’s a throttle position sensor (TPS) reset sometimes cures problems.Ignition on but dont start, press throttle pedal five times to the floor, ignition off.If that doesn't work I’d be checking anything that moves for sticking - cable, linkage, butterflies on roller barrels etcIan Link to comment Share on other sites More sharing options...
ScottR400D Posted November 9, 2018 Share Posted November 9, 2018 Just a thought about the cable, it would be easy to check. If it’s been lubed up and the oil/grease causes it to slide less freely when cold but eases when hot I guess it could do. But as I said, easy to check, just press and release throttle, engine off, when cold. Mine shuts off very quickly. Link to comment Share on other sites More sharing options...
ScottR400D Posted November 9, 2018 Share Posted November 9, 2018 Just a thought about the cable, it would be easy to check. If it’s been lubed up and the oil/grease causes it to slide less freely when cold but eases when hot I guess it could do. But as I said, easy to check, just press and release throttle, engine off, when cold. Mine shuts off very quickly. Link to comment Share on other sites More sharing options...
robert green Posted November 10, 2018 Share Posted November 10, 2018 Cable my first thought. Check the simplest things first!!! Link to comment Share on other sites More sharing options...
Matt230 Posted December 5, 2018 Author Share Posted December 5, 2018 Finally had a chance to get in the garage and have a look at this. It is either the cable or the roller barrels. I took the filter off the barrels and a few seconds after the throttle is released the barrels ares still closing which is why the revs flaring between changes. The cable is clean and has a clear route, i cant see where it attaches to the barrels. Im pleased its mechanical but i cant quite work out what to do from here..... Matt Link to comment Share on other sites More sharing options...
SM25T Posted December 5, 2018 Share Posted December 5, 2018 Or the pivot of the throttle pedal. Disconnect the cable from the top of the pedal and see if the pedal moves freely. Clean and lube if sticky. Then pull on the free end of the cable and see if it still happens at the roller barrels. Link to comment Share on other sites More sharing options...
paul jacobs Posted December 5, 2018 Share Posted December 5, 2018 I have this same problem on a Cosworth 2l. 220bhp Duratec, fitted with roller barrel throttle, but not certain if it is a mechanical problem, which should be easy enough to check, maybe a stronger spring, or likely to be software, as some developers build in this 'rev hang' to burn up excess fuel when cold because of emissions legislation. I would say it is worth speaking to a rolling road specialist about it if you can't sort the mechanical side. Link to comment Share on other sites More sharing options...
David aka Blue7 Posted December 6, 2018 Share Posted December 6, 2018 I agree with Scott & Robert King, sticking throttle cable. I have the same problem on my CSR, it's most noticeable in damp conditions, application of WD40 can help but I have just learned to live with it as another Caterham quirk. It's irritating but disappears after a few gear changes so I just ignore it. A replacement throttle cable or removal and lubrication of existing cable would probably resolve the issue. Link to comment Share on other sites More sharing options...
paul jacobs Posted December 8, 2018 Share Posted December 8, 2018 I doubt it is a sticking cable. If it was, working it a few times before the first start would get rid of the rev hang, and why should the cable only be sticky when cold? Nope it is more likely something to do with emission regs. or mapping I bet. Although it does seem to happen with roller barrel setups more often, so maybe this could be worth investigating - speak to the manufacturer of the RBs. Don't forget to let us know what the answer is, so we can benefit too. Link to comment Share on other sites More sharing options...
ScottR400D Posted December 8, 2018 Share Posted December 8, 2018 OP has already confirmed that the throttles are physically returning to idle slowly when it’s coldHow can that be caused by mapping? Link to comment Share on other sites More sharing options...
Matt230 Posted December 24, 2018 Author Share Posted December 24, 2018 Quick update, finally got to have a look at the car after being away on my honeymoon. Detaching the throttle cable and the roller barrels shut immediately so can discount those. The tension looks like its in the throttle pedal bolt, i have eased that off slightly and the barrels shut a lot quicker now. I haven't had chance to drive it yet as its still up on axle stands, however everything seems a lot more freely moving now. Hopefully the pedal is not too soft thoughThank you all for the replies and messages.Matt Link to comment Share on other sites More sharing options...
SM25T Posted December 24, 2018 Share Posted December 24, 2018 Hurrah. Spot of oil on pivot too. Congratulations on wedding too. Link to comment Share on other sites More sharing options...
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