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  • A series, won't warm start.

    Hi all,

    My A+series maestro won't start warm. Starting from cold it runs like a dream. I'm hoping you may have some ideas that will help.

    I've checked the following:
    Spark plugs (gaps correct, condition a little sooty, cleaned and reused)

    HT leads (visually good, car drives well when started cold - doesn't cut out so long as under acceleration or choke at idle - even once warm. Also checked there is a spark at plugs once it won't start against the block)

    Dizzy cap and rotor arm (visually good, all secure no splits, starts etc just not when warm)

    Ignition coil (I bought a new one - no change in any way)

    Fuel pump (took hose off carb intake and checked getting a good feed on turn over - it is)

    Dash pot oil topped up and gave a clean to the inside chamber whilst I was at it.

    Vacuum hoses are present and correct, no splits.

    ​​​​​
    What's throwing me is that once it's started it doesn't cut out as far as I can tell. It'll idle poorly between normal and dropping revs without choke and eventually will kill itself. But otherwise would keep going with choke. But it won't start on choke once it's switched off and warm.

    The engine seems to be getting warm quicker than usual. Possibly because I don't usually wait for it to get warm and drive on choke for a few minutes (mostly until I'm past all the traffic lights outside my house) but with airflow it seems to stay really cool even after 30 minutes of driving. However sat on the drive I'm noticing it get warm within 10 minutes, easily to half way on gauge and even until the aux fan kicks in.

    The last thing I can think of is valves. I don't have a compression tester which I'm thinking is my next step.

    Am I missing anything else though?

    Any helpful hints appreciated.

    Thanks,
    Charles

  • #2
    This started out the blue, I drove to the supermarket a few nights ago and had to get towed home.

    I think I need to check the fuel is getting to the intake and if the overflow is clear if not. I don't remember seeing where the overflow goes on these. I used to have a tube on the mini that would take fuel do n the side of the engine. Not sure I've seen that on the maestro.

    I've got no puddles so am curious where the fuel is going I'm cranking into it..

    Comment


    • #3
      Have a read as this may help https://maestro.org.uk/forums/forum/...ng-an-a-series
      1958 Ford Consul Convertible. I love this car
      1965 Ford Zodiac Executive. Fab cruiser
      1984 MG Montego EFi in black. Digital dash, nearer completion
      1997 Jaguar Xk8 Convertible. Such a fab car
      2004 MGZT cdti. Great workhorse
      2004 MGZT V8. I love this car

      Comment


      • #4
        Thanks Jeff.

        I went out earlier to have a go at starting, the last few days I've only been able to get one start a day before the daylight disappears. That's with up to 3 hours between starting - not what I'd have called warm.

        To my surprise it started for the second time today, and seems to start again even after getting warm again.

        The last thing I did to the car was refilled the dashpot oil yesterday. This didn't get the car started again yesterday though. This morning it also ran but wouldn't restart once warm.

        It is running like a bag of peanuts though now. I used my engine oil for the dashpot 15/40. I'm going to try some 3-in-1 as it's lighter grade. I've heard pretty much anything will work but it will affect performance.

        I'm assuming there was an issue with the dashpot and now the grade is too thick causing greater resistance on the chamber. Although why it wouldn't start again this morning is confusing me still.

        The tuning post linked should help to get it running right once I've changed the oil over. It was running well on the current adjustments other than the oil before it started seizing ( I assume what was happening). Hopefully it won't take much.

        Will update tomorrow with progress.

        Thanks again

        ​​​​​​​

        Comment


        • #5
          I had the same problem with my morris minor and it was caused by a bad rotor arm.
          you have a different distributor but if it has a bakelite rotor arm with a rivet you might have the same trouble.

          Comment


          • #6
            Hi ,

            Quick update. It's not running at all. It backfires if I crank it long enough.

            Now for the "I think I broke it more and should have got it running first to know for sure" bit...

            Noticed it was leaking petrol from the bottom of the carb from the float chamber seal. Thought I may as well replace the rubber seal if I was taking the top off to drain the oil and replace with 3-in-1...


            Why do I do these things when I know I shouldn't...

            So, it's doing what it was doing, just ticking over and occasionally backfiring, which it started the other day when I replaced the dashpot oil with 15/40.. it's now got 3in1.

            I haven't touched any of the mixture settings other than the float, which I measured when I was seating it. It's a millimetre under the rim when inverted. Which had .5 tolerances I think the booklet said.

            The float needle in the service kit is different slightly to the one I took out. The one in there had a small ball bearing in the end it looks like. The one I put in had a solid brass end. The old one also had a tiny wire hook around it that attached to the brass spring. I couldn't see this in the su diagram so I didn't put it back in (it also didn't fit the end of the new float needle).

            So, I think it's running lean. (I think this is correct for it cranking and backfiring with no running)

            I am now not sure if it's the float or something else which was my problem originally seeing as I didn't change one thing at a time (I should have learnt by now).

            I'll try to adjust mixture and see if I get anything different tomorrow if it doesn't rain torrentially, blow a gale, and hail on me again...

            ​​​​​​If I could move it I'd be tempted to dump my wife's Figaro out of the garage but as I'm not sure I could live with the outcome and don't fancy pushing the car more than I have to, I may just wait for a dry window ​​​

            Comment


            • #7
              Have you checked the state of the plugs during this episode? They can tell you a lot about the mixture. If you check them after a cranking and no running phase and they are wet then this indicates an ignition fault of some sort. In addition if they are black and covered in soot, the mixture is too rich, if they are coffee coloured the mixture is about right and almost white appearance shows its too weak. All plugs should be the same. Any difference is possibly a rotor or dizzy cap fault. Does applying choke (whatever the coolant temperature) ease the problem? If so that is a good guide to the mixture being too weak as well.
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              • #8
                Hi Pete,

                I've actually not had chance until today to work on the car.

                I got a bit hissy with it and bought new plugs, leads, cap and rotor arm because I couldn't think what was causing it as it's getting fuel and it's not firing in the slightest.

                I gave it a short crank before I swapped everything over. Plugs were wet when I pulled them so it's got fuel. The only difference changing it all over is it started to backfire more often. I *think* it's backfiring from the exhaust, although it also previously backfired from the carb, I noticed it when the air box wasn't on the other day.

                I've checked the plug order, I kept wondering if it was that and unless my dizzy was put in upside down it's correct. But I haven't moved it so assume I'd have noticed it it were out before now (?).

                Plugs were black. So definitely rich. It's just the fact it does nothing I find disheartening.

                It got dark very quickly after 5 so I didn't do much more than replace everything and try turning it for about 8 seconds. I felt guilty with the backfiring possibly annoying people. If I had an idea on what to check next I may have done more but thought I'd likely just end up repeating the exercise.

                It seems like an ignition issue (but then I'm hardly qualified to diagnose that). I haven't done anything to effect the timing. The dizzy hasn't been moved. Everything else has been replaced.

                There's fuel all the way to the plugs.

                I won't get chance to look tomorrow. Here's hoping for a dry weekend. Everything is being checked again systematically.

                Edit: I realised I did try something else at the beginning of the week to see what the effect was. That was what caused me to buy new plugs et al.
                ​​​
                I tried turning the mixture screw a quarter turn twice in both directions from where it was to see if it made a difference. It didn't and I adjusted it back to where it had been.
                Last edited by A+MAESTRO; 13th January 2022, 20:36.

                Comment


                • #9
                  do you have a compression tester?

                  Comment


                  • #10
                    Originally posted by A+MAESTRO View Post
                    Hi Pete,

                    The only difference changing it all over is it started to backfire more often. I *think* it's backfiring from the exhaust, although it also previously backfired from the carb, I noticed it when the air box wasn't on the other day.
                    Backfiring through the carb indicates a timing issue, in that it is too far advanced. So the mixture is being ignited while the inlet valve is still open. Backfiring through the exhaust is the opposite and its too retarded so igniting while the exhaust valve is open. If only for peace of mind, it may be worth going back to basics and check the static timing, plug lead sequence, testing that you have a spark at each of the plugs, plug gaps, before trying a start. Although you haven't done anything, something may have moved if the fixing is not completely tight.
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                    MG Maestro Turbo #436 (To keep me occupied in retirement)
                    Rover BRM #385
                    Hyundai Tucson Premier SE (Daily run-around)


                    You know you are getting old when your knees buckle and your belt doesn't

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                    • #11
                      Not to worry, I have discovered my problem.

                      Me!


                      Firing order correct, except not quite, all one plug plug out on the dizzy.

                      The words I have called myself

                      Many thank yous for your suggestions. I had a little trouble with running on the off, I clearly didn't get it back to where I thought it had been. Seems good for now after the useful reading above.

                      I still don't know what the original issue was but it's starting strongly once warm. Could have been dashpot oil, could have been any of the electrics I replaced. I think a bit of all of it possibly.

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