Hi all, hope someone can help me out here, I'm going mad with this one. Bit of a long story, please bear with me!
I have a Defender 90 fitted with a 3.9i V8 from a Disco 1. Been running like that for a couple of years. About a month ago, I was towing a (large) trailer on the motorway when there was a loud bang (sounded mechanical) which I *thought* came from the trailer. Pulled straight onto the shouldwe whereupon the engine stopped and would not start. Had to get it recovered (mate came out, we put my Defender on the trailer it had been towing ). When I got to look at it, there was no spark at the plugs but there was from the coil. Swapped out the cap and arm with old ones I had lying around and we were away again.
Last week, it was running but not brilliantly. Felt like it was down on power, a few times on the motorway on long hills I had to chuck it down a gear but when I did that it sailed up the hills happily, just at higher revs. I've had a lot of RV8s over the years and I know they're sensitive to dizzy cap, rotor arm etc so I ordered replacements from simonbbc. Yesterday I went to fit those. First off I got all the leads one position out (duh) but even when I put them right it wouldn't start. Put the old cap and arm back and way she went.
Today, I needed to go to the shops so I used the Landie, thinking that would warm it up and when I got back I'd try the other cap and arm again and reset the ignition timing (hence my other post yesterday). Swapped the cap and arm out again and it wouldn't start I tried all combos of old and new cap and arm to try and narrow it down, but now it won't run at all. No leads are disconnected, everything is in place. The problem I seem to have is with the spark from the coil. It's not consistent. If I earth the king lead and dab the 12v on and off the coil, it seems to spark fine. If I turn it over with a plug lead earthed, well, there's a spark but not a great one. I even got to the point of taking the dizzy out and spinning it with the ignition on to see if I was getting a spark - yes, kinda, but it wasn't as fat and consistent as I would like.
Coil resistance with my (very) cheap multimeter is coming back at around 9 ohm, which I think is too high? Should be less than 4 I think?
So I'm erring towards the coil breaking down, but could it also be the ignition amplifier? That's what I'm not sure about.
And then, which coil and amp do I need? I was thinking of where I could get one today but Euros only list a Bosch at £92 whereas all the "usuals" list Lucas coils at £20-30, but I can't find a definitive on which one I actually need. And then, which amp do I need. Mine is the one which sits on a bracket alongside the coil, not on the dizzy itself.
EDIT: just realised, with the usual ECP "amazing sale code" it's "only" £60....
All thoughts and input welcome. Am I on the right track here with the coil and/or amp? It's driving me mad. I can't actually believe I went out in it this morning and now it won't run at all.....
TIA.
I have a Defender 90 fitted with a 3.9i V8 from a Disco 1. Been running like that for a couple of years. About a month ago, I was towing a (large) trailer on the motorway when there was a loud bang (sounded mechanical) which I *thought* came from the trailer. Pulled straight onto the shouldwe whereupon the engine stopped and would not start. Had to get it recovered (mate came out, we put my Defender on the trailer it had been towing ). When I got to look at it, there was no spark at the plugs but there was from the coil. Swapped out the cap and arm with old ones I had lying around and we were away again.
Last week, it was running but not brilliantly. Felt like it was down on power, a few times on the motorway on long hills I had to chuck it down a gear but when I did that it sailed up the hills happily, just at higher revs. I've had a lot of RV8s over the years and I know they're sensitive to dizzy cap, rotor arm etc so I ordered replacements from simonbbc. Yesterday I went to fit those. First off I got all the leads one position out (duh) but even when I put them right it wouldn't start. Put the old cap and arm back and way she went.
Today, I needed to go to the shops so I used the Landie, thinking that would warm it up and when I got back I'd try the other cap and arm again and reset the ignition timing (hence my other post yesterday). Swapped the cap and arm out again and it wouldn't start I tried all combos of old and new cap and arm to try and narrow it down, but now it won't run at all. No leads are disconnected, everything is in place. The problem I seem to have is with the spark from the coil. It's not consistent. If I earth the king lead and dab the 12v on and off the coil, it seems to spark fine. If I turn it over with a plug lead earthed, well, there's a spark but not a great one. I even got to the point of taking the dizzy out and spinning it with the ignition on to see if I was getting a spark - yes, kinda, but it wasn't as fat and consistent as I would like.
Coil resistance with my (very) cheap multimeter is coming back at around 9 ohm, which I think is too high? Should be less than 4 I think?
So I'm erring towards the coil breaking down, but could it also be the ignition amplifier? That's what I'm not sure about.
And then, which coil and amp do I need? I was thinking of where I could get one today but Euros only list a Bosch at £92 whereas all the "usuals" list Lucas coils at £20-30, but I can't find a definitive on which one I actually need. And then, which amp do I need. Mine is the one which sits on a bracket alongside the coil, not on the dizzy itself.
EDIT: just realised, with the usual ECP "amazing sale code" it's "only" £60....
All thoughts and input welcome. Am I on the right track here with the coil and/or amp? It's driving me mad. I can't actually believe I went out in it this morning and now it won't run at all.....
TIA.