Josef Posted May 8, 2022 Report Share Posted May 8, 2022 As others have said, unless the clutch is slipping, the engine revs at a given road speed absolutely cannot change. I would definitely temporarily disconnect the rev counter (most likely is driven by an extra wire on the coil -ve terminal) as there is a chance it is misbehaving, and a small chance it might actually be the problem. A broken RVC type rev counter can adversely affect the ignition circuit and in extreme cases prevent the car from running. As we suspect you’ve had earthing issues then that could have affected the circuitry in the tacho, and if the problem doesn’t go away at least that’s something else eliminated from suspicion Link to comment Share on other sites More sharing options...
Quack Posted May 8, 2022 Author Report Share Posted May 8, 2022 @Josef yep fully agree like others said, most likely tacho just playing up. I think it’s just a coincidence that it was okay for a bit after I fitted the new earth and such. @Iain T yeah when I adjust the mixture on the bottom of the carb, it gets jumpier off I go too far each way. I messed with it quite a bit to try get it perfect. To be honest I do think it stopped some of the jumpiness of the car, I can’t remember how many turns I did either way but I think I ended up loosening it in the end, which would make sense because my spark plugs are covered in carbon so maybe the mixture was a bit rich. there is oil in the dash pot, it gloops when I pull it out. Although i believe Pete said to try put new oil in which I didn’t do so I’ll do that. another point to make is that I have some annoying oil leak somewhere but I’m not sure where. I saw one droplet once on the underside of the car but I put cardboard beneath it for a day and a night, and no oil dropped. I do find my spark plugs get oil on the threading though so it’s probably some internal leak. I go through 2 litres of oil a month 😂 anyway Don’t know if this would affect it but thought I should mention. cleaned the air filter too, or atleast as much as I could, it’s nothing outrageously dirty, the car still stutters when I have the air filter off anyway. Link to comment Share on other sites More sharing options...
Iain T Posted May 9, 2022 Report Share Posted May 9, 2022 12 hours ago, Quack said: I can’t remember how many turns I did either way but I think I ended up loosening it in the end, Looking at the carb from the top turning the screw clockwise lowers the jet and makes it richer. Anticlockwise makes it leaner. Or looking at it from underneath clockwise leaner, anticlockwise richer. Clean the plugs, take it for a blast and check the colours. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 9, 2022 Report Share Posted May 9, 2022 you need to completely disconnect the rev counter impulse wire from the coil and re test this idea the revs are wrong can without clutch slip will only be false rev counter displays and yes they are known to upset the ignition this is an un known aftermarket fitment just dump its wires and drive to see what happens forget the dials use the ears mixture . again use the ears turn the mixture adjuster to get the sweetest running the changes are easily noted just turn it 1/4 turn at a time whats happening ??? going wooly is richer lumpy and stallling is weaker but the idea the rvs are climbing is im sorry a misguided by dials not physical happenings Pete Link to comment Share on other sites More sharing options...
Quack Posted May 9, 2022 Author Report Share Posted May 9, 2022 Yeah it’s definitely just the counter that is buggered for the high revs thing, I took it out last night. Cleaned plugs up yesterday too, going to take for a drive and check their colour later on. Engine still stutters and jumps now and then, or misfires, whatever the terminology is, but adjusting mixture seems to have helped a bit. But again it’s a 50 year old car, the chances of something being clogged up are high, something that I can’t access without pulling the engine apart. Its never going to be perfect but atleast it’s a bit better! 1 Link to comment Share on other sites More sharing options...
Quack Posted May 14, 2022 Author Report Share Posted May 14, 2022 Just coming back to this quick, since adjusting the mixture the idle is pretty good now once warmed up, however, I now have to sit on the gas for about 5 mins solid when I first start the car in the morning and Rev it hard, otherwise it just bumps around 400rpm and cuts out. I guess this isn’t too bad to deal with and I’d rather have my fuel mixture correct but still a bit annoying! Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 14, 2022 Report Share Posted May 14, 2022 5 minutes ago, Quack said: Just coming back to this quick, since adjusting the mixture the idle is pretty good now once warmed up, however, I now have to sit on the gas for about 5 mins solid when I first start the car in the morning and Rev it hard, otherwise it just bumps around 400rpm and cuts out. I guess this isn’t too bad to deal with and I’d rather have my fuel mixture correct but still a bit annoying! Not good for a cold engine!! I never liked revving until things had warmed up so if you have to sit with your foot on the pedal keeping the revs high until the temperature rises sufficiently, there's still a problem. Link to comment Share on other sites More sharing options...
Chris A Posted May 14, 2022 Report Share Posted May 14, 2022 Pulling the choke should be enough to keep it running, is the choke set up working? That is what I would ask myself under those conditions. Link to comment Share on other sites More sharing options...
NonMember Posted May 14, 2022 Report Share Posted May 14, 2022 25 minutes ago, Quack said: otherwise it just bumps around 400rpm and cuts out. That sounds like the throttle is not being opened by the choke cam. There's an adjustment bolt, which should be set with about a millimetre clearance when the choke is fully off. The choke should start to operate the throttle before it enriches. Link to comment Share on other sites More sharing options...
johny Posted May 14, 2022 Report Share Posted May 14, 2022 yes Ive got the gap set on my Vitesse to almost nothing as I never start under very cold conditions so dont need much mixture enrichment and just an increased tickover suffices... Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 14, 2022 Report Share Posted May 14, 2022 these cams do seem to wear and a fettle with a file to reprofile a bit can help but on full choke it should give you around the 1200 /1500 or more or it just soots up and stalls being unable to consume the rich mixture this then runs into the sooty plug problems the first 1/2" of choke pull should up the idle without dropping the jet Pete Link to comment Share on other sites More sharing options...
Quack Posted May 14, 2022 Author Report Share Posted May 14, 2022 Yeah I pull out first 1/3 that usually helps the most but still requires a lot of gas for a fair while to keep it from dropping so low it cuts out. full choke certainly doesn’t give me 1200. Once it’s warmed up it runs like a dream but seems just not enough power from the get go to keep it running idle. @NonMember I’m not sure which screw you’re referring to, could you post a picture please if you get the chance? Link to comment Share on other sites More sharing options...
johny Posted May 14, 2022 Report Share Posted May 14, 2022 In this diagram from one of the free to download workshop manuals its item 66. I only need full choke in artic conditions so in the temperatures I normally drive half is enough and that cam screw is adjusted to give a fast idle... carbs.pdf Link to comment Share on other sites More sharing options...
Jeffds1360 Posted May 14, 2022 Report Share Posted May 14, 2022 Like my grandson said "it's got a choke???" I've slightly reprofiled the cam to give faster tickover at 1/4 choke. Never needed more than 3/4 when 5 degrees +. Started today at 14 degrees outside with half but in a few seconds, non required Here's a piece of mine at off Link to comment Share on other sites More sharing options...
NonMember Posted May 14, 2022 Report Share Posted May 14, 2022 4 hours ago, Quack said: I’m not sure which screw you’re referring to, could you post a picture please if you get the chance? It's the one right in the middle of Jeff's picture 😀 Link to comment Share on other sites More sharing options...
Quack Posted May 31, 2022 Author Report Share Posted May 31, 2022 Here we are again, lol. After a good few weeks of the car running perfectly, i'm back to high idle, high counter, and kickback when starting! Started happening again after a 2 hour drive. So bizarre. Since i adjusted the fuel mixture and replaced solenoid & ground it was perfect for ages, but now it's all started again! Don't think i'll ever get to the bottom of it. Link to comment Share on other sites More sharing options...
NonMember Posted May 31, 2022 Report Share Posted May 31, 2022 1 hour ago, Quack said: and kickback when starting! Check the ignition advance when it's misbehaving. You won't always get high idle from it but the kickback is suggestive of too much advance, which could be a result of the centrifugal mechanism sticking. I've had that more than once. If it's a Lucas distributor (ISTR it's a Herald?) then it's perfectly possible to fully dismantle, clean, and reassemble to fix the rust-induced stiction between the inner and outer shaft sections. Dismantling a Delco to that extent is usually terminal. 1 Link to comment Share on other sites More sharing options...
Quack Posted May 31, 2022 Author Report Share Posted May 31, 2022 Yeah the actual rotation of the dizzy can’t have changed as it’s secured tightly. I do however have an electrical ignition though. Link to comment Share on other sites More sharing options...
NonMember Posted May 31, 2022 Report Share Posted May 31, 2022 2 minutes ago, Quack said: do however have an electrical ignition though. Unless it's a 123 type, it's only the points that get replaced by EI - the two advance mechanisms are still the same mechanical, rust-prone, get-stuckable ones. Link to comment Share on other sites More sharing options...
Quack Posted June 1, 2022 Author Report Share Posted June 1, 2022 Ah okay I’ll have a look at it when I get home and see if it needs a bit of a clean up Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 1, 2022 Report Share Posted June 1, 2022 agree advancing will speed up the idle and over advance will kick back on cranking Pete Link to comment Share on other sites More sharing options...
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