Jazzman Posted July 29, 2019 Share Posted July 29, 2019 Dear all, I have a Spitfire mk3 with the original Delco, upgraded with electronic ignition (Pertronix Ignitor module). I decided to get a new unit, hoping to get a better advance curve overall (I guess the original is fairly worn), and sort a 180 out configuration that the previous owner had solved by altering the cables… It is important to note that, before I begun the surgery, the car started and idled at 800 rpm with no problem. I followed all the right steps: car in TDC on piston #1, on compression stroke (I have triple checked it is not 180 out by removing the rocker cover and checking the “blow” through the spark plug hole) Dizzy in, pointing to #1. Static timing with approx. 6-8 deg BTDC. Sadly, I am unable to start the car… The car cranks, but it does not turn on. I have tried with different static timings, from 10 BTDC to 2 ATDC with no luck. After losing half of my hair (and charging the battery three times due to the cranking) I decided to go back to the previous configuration. Again, no luck. I presume it is a timing issue, but I have the feeling I have tried with all the combinations possible between 10BTDC to 2 ATDC. Since I have not been able to start it, dynamic timing with the timing light is not an option. I don’t understand how come the car does not start, it’s a mystery… Any suggestion would be very welcome. Thanks in advance! Quote Link to comment Share on other sites More sharing options...
Velocita Rosso Posted July 29, 2019 Share Posted July 29, 2019 The `trying at different degrees` to start ? By turning the dizzy ,and affixing static , at each point or By turning the dizzy whilst someone turns the key? Quote Link to comment Share on other sites More sharing options...
glang Posted July 29, 2019 Share Posted July 29, 2019 First of all, are you getting a spark? Wouldnt be the first time that a new ignition unit is duff.... Quote Link to comment Share on other sites More sharing options...
Saltddirk Posted July 29, 2019 Share Posted July 29, 2019 I'll be reading this with interest, my Mk2 (with Mk3 Engine) is currently on his way back from Glencoe courtesy of AA. for exactly the same, could not get her going after swapping the dizzy, and the AA send a recovery truck and not a mechanic or even a pair of jumpleads. In my case I suspect that the new Condensator was duff as she was sparking across the points. the resulting spark at the plugs was very weak... D Quote Link to comment Share on other sites More sharing options...
Velocita Rosso Posted July 29, 2019 Share Posted July 29, 2019 Quoted from Saltddirk- I'll be reading this with interest, my Mk2 (with Mk3 Engine) is currently on his way back from Glencoe courtesy of AA. for exactly the same, could not get her going after swapping the dizzy, and the AA send a recovery truck and not a mechanic or even a pair of jumpleads. In my case I suspect that the new Condensator was duff as she was sparking across the points. the resulting spark at the plugs was very weak... D You left it all alone in Scotland....🙄 The Scottish Thistle bug will have eaten it by now... Quote Link to comment Share on other sites More sharing options...
Saltddirk Posted July 30, 2019 Share Posted July 30, 2019 I know, I'm getting into a habit of doing so.... Scotland definitely does not agree with my cars Quote Link to comment Share on other sites More sharing options...
Jazzman Posted July 30, 2019 Author Share Posted July 30, 2019 I worked on the car a little bit last night. So far no success… I did the following checks: I have spark in all four cylinders (I checked with a small device that attaches between spark plug and lead and lights up when it sparks), therefore the dizzy cap, rotor, electronic ignition module and coil work. The spark plugs were full of gas, due to the continuous cranking, but in good order and correct gap (no reason to suspect they’re faulty…) I tried to crank the car and move the dizzy CCW and CW with no result I even advanced the ignition to the point it backfired with a big explosion A bit frustrated I checked for a sticky needle in the carb and the flow of gas to the carbs. All in order… The findings and conclusions so far are that I somehow have some ignition going on, otherwise it would not backfire, right? Could this be caused by a weak spark that is not able to ignite the fuel? Is there any way to diagnose whether the spark is strong enough? The car was working fine before I started messing around with it, so there is no reason to suspect a failing coil… I am running out of troubleshooting ideas… Any ideas? Quote Link to comment Share on other sites More sharing options...
Velocita Rosso Posted July 30, 2019 Share Posted July 30, 2019 If you are thinking weak spark ,then the capacitor may have died or on the way out. I know someone who was changing them regularly as they burnt out. Have you the correct coil to marry up to the dizzy/capacitor(condensor) ? Have you tried taking a plug out ,attaching to ht lead and then plug to earth to see how strong the spark is(preferably in dark area or with cover over the plug to view the spark only)? Quote Link to comment Share on other sites More sharing options...
Jazzman Posted July 30, 2019 Author Share Posted July 30, 2019 I don't have a capacitor since I changed the points with electronic ignition long ago... I will check the spark as you say and revert. Cheers Quote Link to comment Share on other sites More sharing options...
glang Posted July 30, 2019 Share Posted July 30, 2019 Im sure if you have a spark and fuel then, even if weak, there will be some banging. I know you triple checked but it really looks like the spark is coming at the wrong time or to the wrong cylinder - dare I say check it again. For example are you sure one of the trigger magnets is right on the ignition sensor when the rotor is pointing to number one? You can disconnect the wire from the coil to the ignition to power it directly via a 12v bulb to indicate when its triggering.... Quote Link to comment Share on other sites More sharing options...
Velocita Rosso Posted July 30, 2019 Share Posted July 30, 2019 Quoted from Jazzman- I don't have a capacitor since I changed the points with electronic ignition long ago... I will check the spark as you say and revert. Cheers OOps ..sorry half asleep thinking of Dirks problem As stated if you have sparks at the wrong time...eg backfire...then its obvious you have wrong firing order/problem pick up......just for stupidity sake ...just swap your HT leads around....anywhere ...and see what happens. Firing order really being 1342.... but it might get to the root of the problem......and you are certain you are not 180 out? Quote Link to comment Share on other sites More sharing options...
drofgum Posted July 30, 2019 Share Posted July 30, 2019 Jazzman, In your attempt to fix the dizzy being 180 degrees out did you take the distributor drive gear out and turn it 180 or are you just trying to plug things back together with the new dizzy and leads in the new order? The drive gear sets the position of the distributor rotor. The workshop manual gives a fairly clear diagram of the position the drive gear should have when the engine is at TDC for number one cylinder. Best of luck, Paul Quote Link to comment Share on other sites More sharing options...
Matt306 Posted August 2, 2019 Share Posted August 2, 2019 Like Paul said the drive gear slot is off set. I spent ages with similar issues only to realise my folly in putting the gear in 180degrees out. But now i am on Megajolt....programmable curve stronger spark, no dizzy.... first time i drove it like a new car. Quote Link to comment Share on other sites More sharing options...
Matt306 Posted August 2, 2019 Share Posted August 2, 2019 Another thought have you got a ballast resistor on the mk3 ?... they are meant to be bypassed at start up to provide a full 12v for stronger spark. No reason to think that it would be connected as its separate to the dizzy so shouldnt really be related to the problem. Worth checking. Quote Link to comment Share on other sites More sharing options...
Velocita Rosso Posted August 2, 2019 Share Posted August 2, 2019 MK3`s didnt have a ballast resistor. Quote Link to comment Share on other sites More sharing options...
Jazzman Posted August 7, 2019 Author Share Posted August 7, 2019 After a week off, I spent some time with the car again. Following your comments, I checked again the dizzy is not 180 off: I took it out again, then turned the engine to the timing mark and made sure the drive gear was at the right position (roughly horizontal), as per the workshop manual. Put the dizzy back in, with the rotor pointing to the #1 lead cable i.e.: horizontal and pointing to the left. To double check, I put a compressor tester, without the gauge, in the #1 spark plug hole and checked that it blows out when I crank the engine and the rotor is pointing to the #1 lead cable. I am starting to think that I mess the whole process when I static time the engine… I put a mark in the dizzy body with the #1 lead cable position, and I realized that when I static-time the engine the rotor points pass that point, therefore I suspect the spark misses the lead clable rotor cap connection… Could that be the problem? In case it helps, when I crank the engine I hear "puff puff" from the carburettor Quote Link to comment Share on other sites More sharing options...
Dannyb Posted August 7, 2019 Share Posted August 7, 2019 Have you tried loosening the dizzy clamp getting someone to start the car while you move the dizzy by hand. Once started you can then get a timing light on it. Danny Quote Link to comment Share on other sites More sharing options...
Saltddirk Posted August 8, 2019 Share Posted August 8, 2019 Quoted from Jazzman- To double check, I put a compressor tester, without the gauge, in the #1 spark plug hole and checked that it blows out when I crank the engine and the rotor is pointing to the #1 lead cable. I What is the reasoning behind that? I would think that after ignition the piston moves down because of the expanding gasses, so if anything with the volume increasing it should suck in air.... Without plug the air would be pushed out on the compression stroke, before reaching TDC and ignition... or do I see this wrong? D Quote Link to comment Share on other sites More sharing options...
glang Posted August 8, 2019 Share Posted August 8, 2019 I think Jazzman means that as the rotor comes round to the number 1 lead position (firing point) air is being expelled from the number one sparkplug hole so indicating that its piston is coming up to TDC on the compression stroke. Assuming that the engine is rotating in the right direction (clockwise when looking at front pulley) then this is all correct..... Quote Link to comment Share on other sites More sharing options...
Saltddirk Posted August 9, 2019 Share Posted August 9, 2019 thanks, understood correctly, read it badly :)😌 Quote Link to comment Share on other sites More sharing options...
Dale Posted August 11, 2019 Share Posted August 11, 2019 If you are getting a proper 'rifle shot' type backfire then the ignition timing is way off - like 180 out - so the fuel ignites in the exhaust causing the bang. This is definitely an ignition fault and quite possibly the timing is out. Failing that you have 'false triggering' which is when the spark is triggered at the wrong time due to one of a fair few ignition faults. As you have fitted electronic ignition and (apologies if I have misread) it hasn't run properly since, then I would suspect that as the primary issue and go back to points. It is very common for the timing to be changed significantly by fitting or removing electronic ignition and some systems seem to have the firing point in the wrong place by design! Go back to basics and take your time. take the rocker cover off and make sure that you're on the correct TDC i.e. the valves on no. 4 cyl are on the rock (one just closing the other just opening) and the valves on no. 1 cyl aren't moving at all. Then make sure that the rotor arm is pointing at no. 1 cyl and that the points are just opening (Dizzy rotates anti-clockwise). If you do that and it still won't fire or at least cough and sound like it's trying to run then it's not a timing issue. Quote Link to comment Share on other sites More sharing options...
.thumb.jpeg.b15b81ef10abeea1c3039ae03c4a9f3a.jpeg)
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.