BM Posted March 5, 2007 Share Posted March 5, 2007 Help... Just short of work this morning my car developed a sudden misfire of biblical proportions, the exhaust sounded like it was holed. When I got out the car is idling fine, temperatures ok, oil pressure fine, but the Catalytic convertor was glowing cherry red. Have left it all to cool down Any ideas what has gone wrong (only car, so need to sort out). Link to comment Share on other sites More sharing options...
Dickie Normuss Posted March 5, 2007 Share Posted March 5, 2007 Could the internals have collapsed? It could explain the rough running and the overheating? VX HPC - Loud and proud here Watch out, whatever hits the fan will not be distributed evenly Link to comment Share on other sites More sharing options...
BM Posted March 5, 2007 Author Share Posted March 5, 2007 Just started it up and it started fine, isn't blowing. However, I don't want to run it for too long until I know what caused it Link to comment Share on other sites More sharing options...
Graham Perry Posted March 5, 2007 Share Posted March 5, 2007 You haven't got caught out with the dodgy fuel problem have you ? Does the car have a lambda ? Link to comment Share on other sites More sharing options...
mikevernontalktalk.net Posted March 5, 2007 Share Posted March 5, 2007 Edited by - mikevernon@talktalk.net on 5 Mar 2007 13:29:21 Link to comment Share on other sites More sharing options...
BM Posted March 5, 2007 Author Share Posted March 5, 2007 Yes it does, but used every day for past fortnight, and gone now on fourth tank of fuel. Filled up with Shell normal unleaded twice, once with Sainsbury Super Unleaded and once with BP Superunleaded. None of these as far as I am aware have been effected? Link to comment Share on other sites More sharing options...
Frying Pan Posted March 5, 2007 Share Posted March 5, 2007 I wouldn't immediately blame the cat for the initial misfire. If the engine was misfiring badly, then the cat would have had a lot of fuel getting to it, hence the cherry red effect. This may have caused irreparable damage, but as it now starts and sounds OK, you might be lucky. I'd check the HT and ECU side of things. What engine / ECU (r carbs!) are you using? Guy See some pictures of the build here. 11000 miles completed! Link to comment Share on other sites More sharing options...
BM Posted March 5, 2007 Author Share Posted March 5, 2007 Fortunately I'd only driven a half mile at most after it happened. EU3 engine. It has had a very slight misfire recently, very intermitant and not really causing any problem. Had cleaned the electrical contacts on the loom at the weekend using electrical contact cleaner (as this resolved a similar misfire once before). Also had checked all four spark plugs (all ok, greyish with a hint of brown and all about the same colour). Had driven some 10 miles this morning and was behaving perfectly. Had stopped at traffic lights, and temperature hadn't gone high enough to start the fan, so no concerns there. As I went to pull away it literally started misfiring throughout the rev range. Link to comment Share on other sites More sharing options...
old captain slow Posted March 5, 2007 Share Posted March 5, 2007 Is the car a turbo? (assume it's not the 7 you are talking about) Could it be a seal gon in the turbo and the cat is burning off the oil hence red hot? C7 CDW Link to comment Share on other sites More sharing options...
BM Posted March 5, 2007 Author Share Posted March 5, 2007 Cat 7 1.8 K Series (2004) Link to comment Share on other sites More sharing options...
old captain slow Posted March 5, 2007 Share Posted March 5, 2007 Not that then. C7 CDW Link to comment Share on other sites More sharing options...
Red SLR Posted March 5, 2007 Share Posted March 5, 2007 Is it an all in one exhaust or can you un-bolt the cat? LeMans 2006 photos here Link to comment Share on other sites More sharing options...
BM Posted March 5, 2007 Author Share Posted March 5, 2007 An all in one type. Link to comment Share on other sites More sharing options...
Red SLR Posted March 5, 2007 Share Posted March 5, 2007 Ah. LeMans 2006 photos here Link to comment Share on other sites More sharing options...
Rob Walker Posted March 6, 2007 Share Posted March 6, 2007 If the cat is getting excessively hot then your air /fuel mixture is wrong (too rich) this will give exhaust gases that are too high in hydrocarbons . I would look at airtemp, ECU water temp sensor and connections or duff fuel pressure regulator. I would not use the car until its sorted or damage will result. Link to comment Share on other sites More sharing options...
BM Posted March 6, 2007 Author Share Posted March 6, 2007 Cheers, can you explain where each of these are located? Thanks Link to comment Share on other sites More sharing options...
Allen Payne Posted March 6, 2007 Share Posted March 6, 2007 The water temperature sender is in water rail above the exhaust manifold; air temperature in the inlet manifold somewhere and the fuel pressure regulator is the small round thing on the end of the injector fuel rail Link to comment Share on other sites More sharing options...
BM Posted March 6, 2007 Author Share Posted March 6, 2007 Have had a good check over things this lunchtime. Found that the misfire was on the cylinders nearest the back of the engine (black and sooty). I did notice that the 4 wires at the connection from the Lambda to the main loom (at the rear of the engine block) was connected, but not held tightly by the black clips (could simply pull it out without pressing the little lever down). I wondered if this had caused it? Also the loom connection to the front coil pack was similarly connected but not held tightly (both were being forced slightly apart by rubber bit that keeps the dirty out). Any thoughts? Link to comment Share on other sites More sharing options...
Rob Walker Posted March 6, 2007 Share Posted March 6, 2007 If only cyl 3&4 are sooted up then that narrows it down to a HT coil or associated wiring/ecu fault. Link to comment Share on other sites More sharing options...
BM Posted March 6, 2007 Author Share Posted March 6, 2007 I swopped the two coil packs over earlier, so I could see if the problems moves? Link to comment Share on other sites More sharing options...
mav Posted March 6, 2007 Share Posted March 6, 2007 Coil packs not that suspect I'd have thought as 1&4 and 2&3 on EU3 engines... Link to comment Share on other sites More sharing options...
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