dog321fish Posted November 10, 2018 Share Posted November 10, 2018 (edited) 1983 1.8S Berlinetta, Engine revs freely and runs fine aprox 90kmiles. Rev counter sticks at approx 2800 rpm. Any suggestions please? (do not say put your foot down. Speedo rises no ptoblem but tach sticks at 2800 rpm) All electrics OK as far as I can tell. Green wire on coil looks ok. It has a Lucas coil not the original Bosch one, could that be the issue ? Is the ignition module likely to have any effect ? Thanks Dave Edited November 10, 2018 by dog321fish add info Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted November 10, 2018 Share Posted November 10, 2018 Hi. The fact that the engine itself runs fine and has no issues regarding rev limiting and acceleration points to a problem with the actual tacho itself.the tacho gets its signal as pulses from the green wire and intertpets that as a rev speed.it sounds as though either the needle itself is sticking or the unit is faulty. you will need to remove the instrument cover 'hood' and then the heater levers and light switch plugs to get access. the top will swing out to one side.you can removeit completely by unclipping the heater cables but you prob wont need to. once you are inside lift off the cover and the tacho is held in with a couple of srews and lifts out leaving all the rest in place. Check it for sticking or just pop another in to try. Should be plenty about,confirm correct type regarding colour of needle / typeface style . Quote Link to comment Share on other sites More sharing options...
dog321fish Posted November 10, 2018 Author Share Posted November 10, 2018 (edited) Thanks for that will have to find another tacho then. Cheers Edited November 10, 2018 by dog321fish correction Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted November 11, 2018 Share Posted November 11, 2018 If rear of dash is working fine and engine is running fine then I can’t think of any other issues that would cause it. coil won’t matter . did it work originally and has just gone wrong recently ? Quote Link to comment Share on other sites More sharing options...
dog321fish Posted November 11, 2018 Author Share Posted November 11, 2018 Only noticed fault recently, had car new in 1983 and as far as I know fault has appeared this year. Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted November 12, 2018 Share Posted November 12, 2018 Should be plenty tachos around then .ive seen a few breaking ads on here. All manta b / ascona b/ cavalier mk1 ones interchangeable electrically .early up to about 82/83 orange later ones white etc. As I’m sure you know. nice to hear you’ve had car from new. Nothing better than knowing a cars full history. all the best Quote Link to comment Share on other sites More sharing options...
dog321fish Posted November 19, 2018 Author Share Posted November 19, 2018 Well I managed to get another rev counter, it looked good, fitted it at the weekend and the needle goes all the way around and stays there, which is much worse than my original, any suggestions please ? Quote Link to comment Share on other sites More sharing options...
Snowy Posted November 19, 2018 Share Posted November 19, 2018 1 minute ago, dog321fish said: Well I managed to get another rev counter, it looked good, fitted it at the weekend and the needle goes all the way around and stays there, which is much worse than my original, any suggestions please ? Sometimes if they haven't been used for a while they stick. If you tap the dash top you can usually un stick them. If you're lucky a bit of use and it will be fine. Quote Link to comment Share on other sites More sharing options...
®evo03 Posted November 19, 2018 Share Posted November 19, 2018 Had a problem before, the wee half moon wire connection was the problem, cleaned it, adjusted clip stays, and temporary fitted clock, test drive, and rebuilt dash, Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted November 21, 2018 Share Posted November 21, 2018 Hi. So you have got another but the needle just goes round to max on its own ? Or goes up when you rev it and sticks ? If its the latter it just sounds like a stiff spot or maybee the needle is rubbing .?. It sounds like you are one of the very few who have had any sort of issue sith a tacho. Two bad ones after each other is certainly unusual in my experience. the tacho has a 12v feed and an earth(negative) and a signal pulse taken from the green wire .so theres not much realy thatcan go wrong.all supplied by the three pins that plug i to the dashboard. did you try the original for stiffness / freedom of manual movement ? Quote Link to comment Share on other sites More sharing options...
dog321fish Posted November 22, 2018 Author Share Posted November 22, 2018 Needle went round to max as soon as I turned the ignition switch on and stayed there regardless of revs, on a plus the seller is swopping it for me. I have not fiddled with either of them for fear of making them worse. It is really a summer car so no rush to get it fixed, Thanks for all the help. Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted November 24, 2018 Share Posted November 24, 2018 Ok no worries. Still a strange one thou. One thing worth checking whilst the tacho is out although like I said I’ve never had any issues with any before is to make sure you have 12v to one of the three pin sockets ( sorry can’t remember which)in relation to body earth AND the 2nd pin. And that you have continuity between the remaining pin and the green oil lead. can remove mine to confirm pins if realy required but I’m sure you get what I mean. also the pin outs may actually be written on the tacho itself ? Probably +. - I. Or T ..? Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted January 3, 2019 Share Posted January 3, 2019 Are you sorted now ? Quote Link to comment Share on other sites More sharing options...
dog321fish Posted January 8, 2019 Author Share Posted January 8, 2019 Not yet, sent faulty replacement back to seller in November. Waiting for it to be repaired or replaced. Quote Link to comment Share on other sites More sharing options...
dog321fish Posted January 21, 2019 Author Share Posted January 21, 2019 All sorted now 😀 1 Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted January 21, 2019 Share Posted January 21, 2019 Great. Glad you’ve got it working. Quote Link to comment Share on other sites More sharing options...
MrCarlos Posted January 26, 2019 Share Posted January 26, 2019 On 21/01/2019 at 18:39, dog321fish said: All sorted now 😀 Excellent 🙂 got there in the end Quote Link to comment Share on other sites More sharing options...
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