Ignition Module
Discussion
Bit of a poser! (the car not me)
It wouldn't start and fuel was OK so tested spark, and no spark at plugs. Coil is OK (used strobe timing light in HT socket), delivers spark to ditributor but gets no further. Distributor cap is OK (carbon contact is there, rotor arm isn't bust). So all I can think now is that ignition module doesn't just cause spark to be created, it governs when it's created and its sparking when rotor arm isn't against a contact.
Any suggestions gratefully received!!!
It wouldn't start and fuel was OK so tested spark, and no spark at plugs. Coil is OK (used strobe timing light in HT socket), delivers spark to ditributor but gets no further. Distributor cap is OK (carbon contact is there, rotor arm isn't bust). So all I can think now is that ignition module doesn't just cause spark to be created, it governs when it's created and its sparking when rotor arm isn't against a contact.
Any suggestions gratefully received!!!
What makes you think that the amplifier is broken if the HT output of the coil is fine? If that's working and you're getting a good spark from the HT supply (stick a plug on the connection to the centre of the dizzy) then there must be something wrong in the dizzy, like the condensor may be short circuit.
xain said: What makes you think that the amplifier is broken if the HT output of the coil is fine? If that's working and you're getting a good spark from the HT supply (stick a plug on the connection to the centre of the dizzy) then there must be something wrong in the dizzy, like the condensor may be short circuit.
I think you will find there is no condenser in an electronic distributor.
The most likely cause (if the king lead from coil to distributor is OK) is the rotor arm is shorting to earth internally, or the cap is breaking down and arcing to ground. Although if it is the cap, it would more likely cause a missfire rather than a complete loss of spark.
Anyway, try replacing the rotor and cap.
Paul.
Cheers Paul
Replaced both cap and rotor arm, but still firing where it shouldn't - into exhaust and inlet manifolds. At least it's (barely) running. So can't think of anything else but ignition module. I ordered one today - why does it cost £38 from Lucas and £108 from a TVR dealer? TVR ownership is dear enough without that sort of mark-up!
TonyP
Replaced both cap and rotor arm, but still firing where it shouldn't - into exhaust and inlet manifolds. At least it's (barely) running. So can't think of anything else but ignition module. I ordered one today - why does it cost £38 from Lucas and £108 from a TVR dealer? TVR ownership is dear enough without that sort of mark-up!
TonyP
Broken HT lead?
If the spark is getting to the plugs but too weak, could be there's some fault somewhere which is preventing you from getting a string spark, good enough when you measure it directly at the coil but not enough by the time it has jumped gaps in the dizzy and made its way down the resistive plug leads. If the strength is OK but at the wrong time, is it possible the dizzy has been physically moved while all this was going on? Your plan of replacing the ignition module is a good one anyway, if that doesn't help at least you've got a spare.
If the spark is getting to the plugs but too weak, could be there's some fault somewhere which is preventing you from getting a string spark, good enough when you measure it directly at the coil but not enough by the time it has jumped gaps in the dizzy and made its way down the resistive plug leads. If the strength is OK but at the wrong time, is it possible the dizzy has been physically moved while all this was going on? Your plan of replacing the ignition module is a good one anyway, if that doesn't help at least you've got a spare.
cess said: Thanks Peter,
The spark is a belter (about half inch) and I changed the leads too (a busy weekend!) as I thought I would rule out everything else. Dizzy hasn't been moved except to take cap off, but not rotated.
Better be that damn module!!!
Don't do it yet. If you have a spark that is occurring at the wrong time, either the timing is out or (sounds more likely) the HT leads have become mixed up. Get the engine to TDC with No 1 firing (rotor arm should be pointing at No1 electrode in cap). That will show if the timing is roughly right.
Then check the leads are in the right order. I don't have the firing order to hand or cylinder numbering sequence to hand, but if you need it, just ask.
Paul.
>> Edited by B16 RFF on Wednesday 11th June 21:38
Hi Peter
Thanks for the help.
I had checked firing order with the (new) bible so I knew that was OK. I fitted the new module last night, and works fine now - smoother than it's been for a while so I guess it must have been on it's way out.
It seemed to be sparking too quickly before so I think it must have been sparking a couple of times around each dizzy contact to make it fire into exhaust / inlet. At least I know now the module doesn't just control the creation of the spark - it controls the timing of the spark as well.
Thanks for help of all
TonyP
Thanks for the help.
I had checked firing order with the (new) bible so I knew that was OK. I fitted the new module last night, and works fine now - smoother than it's been for a while so I guess it must have been on it's way out.
It seemed to be sparking too quickly before so I think it must have been sparking a couple of times around each dizzy contact to make it fire into exhaust / inlet. At least I know now the module doesn't just control the creation of the spark - it controls the timing of the spark as well.
Thanks for help of all
TonyP
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