zoltan Posted June 23, 2011 Share Posted June 23, 2011 I have a Snap-On digital timing light, donkeys years old which works all day long on 4 cylinder wasted spark engines (halve the reading each time) but will not flash on the mark on my current V8 Megasquirt project (non Land Rover). I've been round and round with this now and it is irritating me somewhat. I'm thinking I've missed something obvious. I have checked: Timing light is on cylinder 1 lead Cylinder is on firing/should be firing stroke as evidenced by borescope showing both valves closed, with piston at TDC (so not 180 out) Crank trigger position is correct to TDC and the sensor (5 teeth after the gap) The paint/tippex mark on the flywheel is correct to the TDC mark on the bell housing. TDC mark was checked with a dial gauge Im not seeing my paint mark anywhere despite the strobe firing away and a timing trim figure of about 4 degrees in Megatune. I can literally go round the clock and still not see that paint/tippex mark I know some timing lights have issues with wasted spark but why does this light work on 4 cylinder and yet this V8 shows a problem? What am I missing here? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 23, 2011 Share Posted June 23, 2011 I'm thinking you probably have your EDIS ABCD wires muddled up -not taking the tiddle, I have done it before without realising(!) Try the timing light on the other coils, see if you get a mark then. If so... check your wiring Even if it was 180 out you would still get a spark to illuminate the marks, so not that. I think you've pretty much exhausted anything else really Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted June 23, 2011 Share Posted June 23, 2011 Cylinders one and six fire together - try the clip on Number six - it worked for me.... Quote Link to comment Share on other sites More sharing options...
zoltan Posted June 23, 2011 Author Share Posted June 23, 2011 I'm thinking you probably have your EDIS ABCD wires muddled up -not taking the tiddle, I have done it before without realising(!) Try the timing light on the other coils, see if you get a mark then. If so... check your wiring Even if it was 180 out you would still get a spark to illuminate the marks, so not that. I think you've pretty much exhausted anything else really When you say EDIS ABCD wires you mean the coil drivers from the EDIS to the coil? The LH and RH wires in the coil plugs? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 23, 2011 Share Posted June 23, 2011 When you say EDIS ABCD wires you mean the coil drivers from the EDIS to the coil? The LH and RH wires in the coil plugs? Exactly! Try the light on other HT leads and see if one lines up, that's probably your A and therefore 1 & 6. Quote Link to comment Share on other sites More sharing options...
steve_d Posted June 23, 2011 Share Posted June 23, 2011 I was told, but don't know if it is true, that on a wasted spark coil the spark goes in one direction on one terminal of the coil and in the other direction on the other terminal. If this is true it may effect the timing light sensor as mine shows that it must be fitted to the lead with the arrow pointing in the direction of the spark. Steve Quote Link to comment Share on other sites More sharing options...
zoltan Posted June 23, 2011 Author Share Posted June 23, 2011 At this point I will try literally anything just to get a reading. I'll see if this makes a difference Quote Link to comment Share on other sites More sharing options...
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.
Note: Your post will require moderator approval before it will be visible.