ECR Posted February 5, 2016 Share Posted February 5, 2016 I have a random misfire on all 4 cyllinders in the Elise. I also have a fluctuating tick-over. I've replaced the throttle pot, fuel filter, cleaned the injectors, replaced plugs (all the obvious things) but am now forced to consider the crank sender. There are a couple on EBay that I could try if they're suitable ...? Link to comment Share on other sites More sharing options...
Sim Posted February 5, 2016 Share Posted February 5, 2016 Can't help with the crank sender itself - Have you looked on Eliseparts?Are you EU2 or EU3 ?HT leads or coil failing ?The routing of the Crank sender lead has slso been known to cause misfiring problems in a 7. Simon Link to comment Share on other sites More sharing options...
Mankee Posted February 5, 2016 Share Posted February 5, 2016 I think I've got a spare working one somewhere, Roger, if you want to try it. Crank sensors normally work or they don't. As noted by Simon, there is a webpage somewhere (might have been Angus' or Myles') that described the distributor king lead interfering with the crank sensor signal and causing the misfire, if you run that ignition setup. Link to comment Share on other sites More sharing options...
revilla Posted February 5, 2016 Share Posted February 5, 2016 I think they are all compatible; but given that they are just a coil of wire around a magnet, I think they would either tend to work or not work, not give an intermittent misfire. Link to comment Share on other sites More sharing options...
Gloucestershire AR Posted February 5, 2016 Share Posted February 5, 2016 Fuel pump? Or maybe a loose wire/connection somewhere?Andy Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted February 5, 2016 Member Share Posted February 5, 2016 As noted by Simon, there is a webpage somewhere (might have been Angus' or Myles') that described the distributor king lead interfering with the crank sensor signal and causing the misfire, if you run that ignition setup.DVA mentions it in this thread.Jonathan Link to comment Share on other sites More sharing options...
ECR Posted February 5, 2016 Author Share Posted February 5, 2016 It's EU3 .....Thanks for the offer Mankee but if I can confirm that the Ebay ones are correct for the car I'll buy one. At £7.00 it's a cheap swap out.Fuel pressure good and consistent under load Link to comment Share on other sites More sharing options...
ECR Posted February 5, 2016 Author Share Posted February 5, 2016 This from the Eliseparts web site"If this sensor is "suspect" the engine will possibly not start at all, stumble on acceleration, idle will be poor or non existent."I've experienced the stumbling and idle symptoms so I'm hopeful ..... Link to comment Share on other sites More sharing options...
simonpa Posted February 5, 2016 Share Posted February 5, 2016 I had an EU2 Elise with similar symptoms.I swapped the coil for a new one and normal service resumed. It's a very common failure. I'd try that first - it's much more likely to be a coil then the crank (flywheel) sensor. Link to comment Share on other sites More sharing options...
ECR Posted February 5, 2016 Author Share Posted February 5, 2016 I have the on plug coils (2) and misfire on all cylinders. I have difficulty thinking that both coils went down at the same time ... ?I could be wrong though, Im still finding my way with the K series (a VX man of long standing ) Link to comment Share on other sites More sharing options...
ECR Posted February 6, 2016 Author Share Posted February 6, 2016 I suddenly remembered last night that I have swapped the coils for another set from a friends Elise and the problem was still there .... Link to comment Share on other sites More sharing options...
Kevsta Posted February 8, 2016 Share Posted February 8, 2016 On my caterham my fuel pump failed. It was failing and the only symptom initially was that the car would feel like it misfired. First time it did it was on track and the thump it gave was horrible (and stopped the day for me). Driving home it did it a few times at random. I was tracing it for about three months when finally it truly failed and the car wouldn't start. Replaced the pump and all was then fixed. I too tried TPS, coilpacks leads etc. Fuel pressure was fine but then the pump would skip a beat and that was what caused the apparent misfire. Best wishes Kevin Link to comment Share on other sites More sharing options...
ECR Posted February 9, 2016 Author Share Posted February 9, 2016 S'pose it could always be a head gasket ......But misfire on all 4 cylinders ? Link to comment Share on other sites More sharing options...
Slipper man Posted February 13, 2016 Share Posted February 13, 2016 Unlikely to be the head gasket I think. On the earlier K's, the gasket goes normally because the line of rubber seals breaks down (my Monza problem occurred on a non-standard gasket). A test pressurising the water should show that up. As you say, it is hard to imagine it causing all 4 cylinders to misfire.Can you swap the sender with Martin's to see if that is the problem? What is the battery voltage like? The symptoms could be explained by voltage drops. I had something similar when I had a duff battery at the same time as (possibly caused by) a failed alternator Link to comment Share on other sites More sharing options...
John Vine Posted February 13, 2016 Share Posted February 13, 2016 Roger, do you have any specific fault codes? JV Link to comment Share on other sites More sharing options...
OliverSedlacek Posted February 13, 2016 Share Posted February 13, 2016 If you're looking at the less common causes then the possibilities increase. I had similar symptoms and it turned out that the alternator was the culprit. The rectifiers were failing intermittently a spiking the battery line. This was momentarily upsetting the ECU. Link to comment Share on other sites More sharing options...
ECR Posted February 13, 2016 Author Share Posted February 13, 2016 JohnP00300 Random misfireP00301,2,3,4 misfire detected on cylinders 1,2,3,4P1301 Misfire detected causing emissions increaseThe misfires were pretty severe during a trip back from Portugal but they have decreased and are now only just discernable. This led me to fuel supply but all that has been cleanedKeith. Replacement sender arrived yesterday which I'll fit when/if the weather improves. Battery fully charged. The cooling system holds pressure for hours .....Oliver thanks for that suggestion ....I'm still trying to familiarise myself with my OBD Link real time code reader. That should help narrow the field down a bit Link to comment Share on other sites More sharing options...
John Vine Posted February 14, 2016 Share Posted February 14, 2016 Hmmm...so the codes just tell you what you already know! Useful.Out of interest, is there any logging software available that would hook into your OBD Link (similar to Easimap for MBE ECUs)? If so, I imagine a laptop logging session while out on the road would help.JV Link to comment Share on other sites More sharing options...
ECR Posted February 14, 2016 Author Share Posted February 14, 2016 Yes, OBDlink has an Iphone app that logs any number of engine parameters to a .CSV file for viewing. It can also log to a laptop based programme, OBD whiz, which has similar possibilities to the easimap programme. Like your experience with easimap though, it takes a little understanding at first Link to comment Share on other sites More sharing options...
ECR Posted February 19, 2016 Author Share Posted February 19, 2016 For future reference:Problem now fixed. I replaced the crank sender, still the same. I then replaced the pre cat lambda sender and voila ! problem solved. No missfire and steady tickoverI must have had an intermittent fault with the lambda sender because I got missfire error codes and no lambda error code. The lambda finally failed and posted an error code which is why I replaced it. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted February 19, 2016 Member Share Posted February 19, 2016 Well sorted. And that will be useful to someone else some day.Jonathan Link to comment Share on other sites More sharing options...
John Vine Posted February 19, 2016 Share Posted February 19, 2016 Well done, Roger! I'm wondering whether an OBDwiz log would have flagged up the lambda fault? IME, Easimap would have (for an MBE).JV Link to comment Share on other sites More sharing options...
ECR Posted February 19, 2016 Author Share Posted February 19, 2016 Yes, looking back at a file I downloaded (but didn't understand at the time) it did just that. The post cat voltage was continually varying (as it should) but the pre cat voltage was flat. Link to comment Share on other sites More sharing options...
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