martin barlow Posted May 22 Report Share Posted May 22 Afternoon Had my 68 mk3 spitfire for almost 3 years with very little trouble.A couple of weeks ago noticed a bit of a hiccup when accelerating but put it down to not being warm.Went out Sunday for a few miles and began missing badly ending up at the side of the road after a rather large bang.Tried starting turned over fine but no attempt to fire.As luck would have it number 2 son owes me many tows so got brought home.Went out the other day to play and started working through-no spark at plugs so tried King lead and looked like a spark.Had spare cap and rotor so tried them nothing-car has electronic ignition so being old was a bit lost-tried to check coil but got no readings that made sense so been to my local spares store (Ask in Kippax near Leeds-if carslberg did car spares shops !!)and borrowed a suitable coil-still no firing but looked at static timing and rotor when timing marks roughly lined up was pointing at cylinder 2-I am sure I have not moved any leads about but moving them all 1 step round car fired up straightaway-thinking that was it put the old coil back on ran dog rough for a few seconds the gave up.I have put the new borrowed coil on and running o.k-far from perfect but had the plug gaps wider for the electronic ignition but before I go any further fiddling about( class myself as an enthusiastic amateur who is quite capable of going in wrong direction) am I missing anything?it took me to Silverstone last year from Leeds and have booked for Malvern so need to have more confidence in my ability than I have at present-all help appreciated Link to comment Share on other sites More sharing options...
johny Posted May 22 Report Share Posted May 22 First before you change anything else I would get the crank timing mark lined up ensuring no 1 cylinder is on compression. That is remove no 1 sparkplug and you should feel air being pushed out as the crank is turned clockwise just coming up to the timing mark. Then confirm which lead the rotor arm is pointing to in the distributor cap... Link to comment Share on other sites More sharing options...
Steve P Posted May 22 Report Share Posted May 22 And to state the bleeding obvious, make sure the dizzy isn`t loose in the clamp. S Link to comment Share on other sites More sharing options...
Iain T Posted May 22 Report Share Posted May 22 (edited) Unseen crack in the rotor arm? It's happened to me. Do you have a spare you could fit? It can cause arcing and misfire. Iain Edited May 22 by Iain T Link to comment Share on other sites More sharing options...
martin barlow Posted May 22 Author Report Share Posted May 22 Thanks for the quick replies-have moved dizzy so that's fine have tried other rotor arms but have also just got a new one-will check no 1 cylinder tomorrow. Link to comment Share on other sites More sharing options...
johny Posted May 22 Report Share Posted May 22 Yes if it was running previously it cant be adjustments that are wrong so probably something failed like electronic ignition, coil, distributor advance mechanism stuck etc Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 22 Report Share Posted May 22 its worth checking the coil 12v is correct polarity dizzy to neg ,ign to pos. do you happen to have spark plugs with and R in the suffix ???? and new plugs ???? Link to comment Share on other sites More sharing options...
martin barlow Posted May 22 Author Report Share Posted May 22 Hi Pete Had a flame thrower coil on presumably to suit electronic ignition fitted by previous owner-polarity fine-tried testing it and couldn't get ohms reading anything near what it should be-as I said have a fantastic spares shop nearby who had a standard 12 volt coil with correct fittings- put that on and still no start and backfiring-looked again at distributor and static timing and rotor was pointing at number 2 lead-moved leads to next ones fired up Straightaway what I cannot understand is why the problem started and how the timing has become miles out-definately have not put the leads on any different from where they have been for the last three years-only spotted the rotor being odd as in the past have managed to get things miles out and backfiring by connecting things up wrong Puzzled of Leeds Link to comment Share on other sites More sharing options...
johny Posted May 22 Report Share Posted May 22 I dont understand how it can be running ok and then suddenly the leads are in the wrong position! Puzzled of Kent Link to comment Share on other sites More sharing options...
martin barlow Posted May 22 Author Report Share Posted May 22 Hi Johny Sorry beginning to get a bit like war and peace-only noticed rotor pointing at no 2 plug lead rather than number 1 when I checked static timing-i also have no idea why the timing suddenly looks to be miles out when as far as I aware nothing should have changed-as I say car now running but doesn't seem happy-as I have taken a flame thrower coil off which must have been put on for the electronic ignition I will run through everything tomorrow to see if I need to adjust anything/everything again-the joys of old cars!! Link to comment Share on other sites More sharing options...
johny Posted May 23 Report Share Posted May 23 As Steve said previously the only thing that would explain the change is that the distributor body isnt clamped solidly at it base so has been free to move. With the clamp loose it has rotated itself so far round that number two position has now taken the place of 1.... Link to comment Share on other sites More sharing options...
martin barlow Posted May 23 Author Report Share Posted May 23 Hi Johny The distributor has definitely not moved-have had the car three years and this is the first running issue-car is now running with the occasional backfire got new cap and rotor due so will check them and see but although timing can alter over time as sometimes seems to happen with cars which even after fiddling with them for over 50 years some things might have to remain a mystery-thanks to everyone for your help an Pete definitely no r in the plug numbers Thanks again Link to comment Share on other sites More sharing options...
johny Posted May 23 Report Share Posted May 23 Have just remembered another possible explanation. Some models have a rubber damper system on the crankshaft pulley to reduce vibration and its in the form of a bonded in rubber ring between the centre that fits to the crank and the outer part with the timing marks. Theres been quite a few cases of this rubber part finally degrading sufficiently to allow movement between the two with the result that the timing marks can no longer be relied apon. If this has happened in your case when you think your at TDC youre not so of course the ignition timing seems to be incorrect. You might be able to feel movement between inner and outer or otherwise try to feel for the top pistion of the no1 piston through its sparkplug hole to confirm that it matches the mark... Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 23 Report Share Posted May 23 have you thought about timing chain has skipped tooth or two unusual but it would explain the shift , failed tensioner.hooked teeth and so on so cam timing and dizzy are all wrong Pete Link to comment Share on other sites More sharing options...
martin barlow Posted May 23 Author Report Share Posted May 23 Hi again Johny looked at that and seems fine-pete thought of that but wasn't sure it could happen-looking at how things have panned out the coil looks to have been the original problem-your idea looks to have then occurred-car is now running on new coil-checked tappets and they are spot on and got new rotor arm and cap to go on - when warmed up this morning still a small backfire on revving up but haven't been out yet as roads still wet-hopefully any other problems will be sorted-thanks again for all your help Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 26 Report Share Posted May 26 from the booklet and web site it seems aldon have been dropped from the stock list magnetronic is Lumenition seems J padock only now sell lumenition aldon is available direct from themselvs or places like Buy Aldon Automotive Ignitor Electronic Ignition Kits | Demon Tweeks Link to comment Share on other sites More sharing options...
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