Non-starter... has us SOOO baffled
Discussion
Hello all...
'98 Griff 500, just wouldn't start one evening...
Got a auto-diagnostic dude out, top bloke, patience of a saint..
He works out that the ignition module is down, so replaces it. Still, no spark at the plugs... this leads to show that the dizzy arm is gone too (it's earthing the now-healthy spark, not routing it to plugs), which he says may have happened as a result of constant attempts to start it with the blown ignition module, or it may have been on the way out anyway. So, we get new dizzy arm and cap, and plugs too for the hell of it.
Anyway, midway through the plug change (by now, new dizzy and dizzy arm are fitted) he starts it just to check, and hurrah, it starts first time. All sorted, or so we think...
He cuts the engine to finish plug change, and when we try and restart it five minutes later... you guessed it, it won't start... and the tracing of fault suggest that once again the (new) ignition module is gone – the original problem! How can this be?
Fuel and all other things are OK, so this is an odd one... are there any specific problems that are associated with the ignition module? I THINK he got a pattern ignition module when he got the new one... is that a no-no, and would a pattern one break within – literally – seconds of being used on a running engine? Or, is there a specific fault elsewhere that would lead to the ignition module frying when the engine is turned off? When it wouldn't start the first time, it had been absolutely fine and dandy on the previous run, so did the ingition moduole fry the time I turned it off then? is this what it will do everythime I turn it off?
I also saw an issue in other threads with the heatsink also being an earth? Would replacing the backing plate, or attaching it with more care/force/cleaner bolts be an answer? is there a way to check if the heatsink/earth isn't working correctly, such as attaching it elsewhere as a bodge?
I cannot tell you how annoying this is, as everything else seems fine. It's taken about four visits over 10 days of this bloke coming back time and again to work (where the car is abandoned) to get to this point, and if he comes with a new module tomorrow and it also doesn't start, or fails to restart after running OK for a few moments, I predict bad things!
As said, on the face of it he is doing everything correctly, and his van is festooned with testers and widgets that rule out problem after problem and trace it down to this ignition module each time. The one things he DOESN'T have tho is a fault reader for the ECU, but the nature of the problem doesn't make it look like it could possibly be based there.
Mucho confusion regins...
Please help, electrics gurus...
'98 Griff 500, just wouldn't start one evening...
Got a auto-diagnostic dude out, top bloke, patience of a saint..
He works out that the ignition module is down, so replaces it. Still, no spark at the plugs... this leads to show that the dizzy arm is gone too (it's earthing the now-healthy spark, not routing it to plugs), which he says may have happened as a result of constant attempts to start it with the blown ignition module, or it may have been on the way out anyway. So, we get new dizzy arm and cap, and plugs too for the hell of it.
Anyway, midway through the plug change (by now, new dizzy and dizzy arm are fitted) he starts it just to check, and hurrah, it starts first time. All sorted, or so we think...
He cuts the engine to finish plug change, and when we try and restart it five minutes later... you guessed it, it won't start... and the tracing of fault suggest that once again the (new) ignition module is gone – the original problem! How can this be?
Fuel and all other things are OK, so this is an odd one... are there any specific problems that are associated with the ignition module? I THINK he got a pattern ignition module when he got the new one... is that a no-no, and would a pattern one break within – literally – seconds of being used on a running engine? Or, is there a specific fault elsewhere that would lead to the ignition module frying when the engine is turned off? When it wouldn't start the first time, it had been absolutely fine and dandy on the previous run, so did the ingition moduole fry the time I turned it off then? is this what it will do everythime I turn it off?
I also saw an issue in other threads with the heatsink also being an earth? Would replacing the backing plate, or attaching it with more care/force/cleaner bolts be an answer? is there a way to check if the heatsink/earth isn't working correctly, such as attaching it elsewhere as a bodge?
I cannot tell you how annoying this is, as everything else seems fine. It's taken about four visits over 10 days of this bloke coming back time and again to work (where the car is abandoned) to get to this point, and if he comes with a new module tomorrow and it also doesn't start, or fails to restart after running OK for a few moments, I predict bad things!
As said, on the face of it he is doing everything correctly, and his van is festooned with testers and widgets that rule out problem after problem and trace it down to this ignition module each time. The one things he DOESN'T have tho is a fault reader for the ECU, but the nature of the problem doesn't make it look like it could possibly be based there.
Mucho confusion regins...
Please help, electrics gurus...
McGriff I think a thread I started some time ago after being told to change my cjeapy one back to a proper one 
might be of interest and maybe help Here.
From my understanding and that is if you have the one that isnt on the dizzy but its own Bracket is that it
uses that bracket as an earth so it needs to sits tight on it. One of my threads had gone on the holding screw to mine and I have now bolted it onto the bracket.
Hope that may help, maybe your one was loose and the sparking and believe me it will if its not earthed well was enough to upset/fry it.
BB
might be of interest and maybe help Here. From my understanding and that is if you have the one that isnt on the dizzy but its own Bracket is that it
uses that bracket as an earth so it needs to sits tight on it. One of my threads had gone on the holding screw to mine and I have now bolted it onto the bracket.
Hope that may help, maybe your one was loose and the sparking and believe me it will if its not earthed well was enough to upset/fry it.
BB
Are you sure the module is actually failing or is it just giving the symptoms of failing. I dont think you can test them properly without a scope. I remember Deeen had a similar problem on his chim, we swapped over my ign module with his and it worked fine so he got a new module only to find the problem re appeared, we put my module back on and all was good again. He eventually traced the problem to a broken wire than ran from the module to the plug that is attached to the ally brakcet. It was only that when we swapped over the module we also swapped the bracket that the problem went away. I have a motaquip module on mine and its fine, they are made in the same factory as the Lucas ones anyway.
>> Edited by wildeep on Tuesday 15th November 21:23
>> Edited by wildeep on Tuesday 15th November 21:23
On mine the coil is unballasted; a coil designed to be ballasted would draw too much current and might potentially overload the ignition module? I'd also suggest you completely bypass the original wiring for the coil and ignition module and see if that cures the problem. The only wire you need to retain is from the coil -ve to the ECU. This should have s snubber diode in it, you might want to check that's intact while you're at it.
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