I have contributed this as I have watched the pleas of"My 505 won't start" and the parts swapping that accompanies the owners efforts.This, I term rectification by substitution.Also it can be called "Wilfull dismantling".
This hybrid ignition system sorted out the mechanics who were stuck in the EH era--and they stayed there!And things are even more technical now,and as manufacturers make cars more complex[mainly due to legislation and bean counters] its getting worse.
After the engine,fuel pump etc, is checked that its mechanically sound,the diagnosis can begin.If its proven there is no spark,this is a short lesson on trouble shooting the ignition on electronic ignition on such as 505 2.2 litre OHC Engines,once more fuel in tank,clean battery terminals,etc,etc.??
1. there MUST be 12v at the + coil terminal.Key ON
2. the module must be coated--lightly with heat paste on back of module,but not too much as it can cause problems if its covering the brass earthing ferrule in the module or shorting out the push on terminals.
3.the coil [there were about 20 listed--not anymore though] should be less than 1-one ohm resistance thru the primary circuit,Then primary to secondary 5 to 7 K ohms,that doesnt seem very important to Bosch.Jaycar/Repco type DMMs are not sensitive below about 3 ohms,so Fluke is the only way to measure primary windings.
4.Reluctor coil inside distributer-this the most vunerable part of the system IMO,approx 2800 turns very light wire ,2 to 2.2 k oms,can give cold or hot start problems -I've struck both.It puts out AC voltage, 2 to 4 v ac if you spin the dizzy shaft [out of the car] to 100v ac spinning full bore in the engine.
I'll upload some scope patterns, you can only work on these things with a scope---[that's what stuffs our EH blokes] even then you have to know what you're looking at.
5. Module and wiring, and here's a trap --if by chance over the years somebody has managed to plug the cable from dizzy to module back to front--[remember any thing is possible!] or have cut and joined the 2 wires reversed,or if the permanent reluctor magnets get reversed polarity
The the firing of the module would then be on the falling edge of the AC wave instead of the rising edge,this would cause the module to be completely scrambled ,and cook up eventually ,you would have to ask one of the boffins about that!It would run but for how long? The dwell would work in reverse.Or just hang up.
So the module must fire on the rising ramp of the wave.This controls the dwell time.
Also there is light screen over the dizzy to module lead,I haven't bothered to have a good look at one,but I'll bet its earthed one end and acts as a ground loop screen,it would be good fun finding an intermittent misfire caused by a module getting stray spikes!
This is a rough and ready article no mention of cracked dizzy caps coil towers so on,just an indication of why a no start needs some one with a scope and able to use it--it saves you from guessing and from buying heaps of stuff you don't need.And rule one tricky bit out.If you have spark move on.
I also have the ECU scope patterns but if you are in that deep you would have a rare one
Made mistake,the earthing ferrel is on the Holden hybrid module ,505 is in the plugin cable - sorry .
broomy
This hybrid ignition system sorted out the mechanics who were stuck in the EH era--and they stayed there!And things are even more technical now,and as manufacturers make cars more complex[mainly due to legislation and bean counters] its getting worse.
After the engine,fuel pump etc, is checked that its mechanically sound,the diagnosis can begin.If its proven there is no spark,this is a short lesson on trouble shooting the ignition on electronic ignition on such as 505 2.2 litre OHC Engines,once more fuel in tank,clean battery terminals,etc,etc.??
1. there MUST be 12v at the + coil terminal.Key ON
2. the module must be coated--lightly with heat paste on back of module,but not too much as it can cause problems if its covering the brass earthing ferrule in the module or shorting out the push on terminals.
3.the coil [there were about 20 listed--not anymore though] should be less than 1-one ohm resistance thru the primary circuit,Then primary to secondary 5 to 7 K ohms,that doesnt seem very important to Bosch.Jaycar/Repco type DMMs are not sensitive below about 3 ohms,so Fluke is the only way to measure primary windings.
4.Reluctor coil inside distributer-this the most vunerable part of the system IMO,approx 2800 turns very light wire ,2 to 2.2 k oms,can give cold or hot start problems -I've struck both.It puts out AC voltage, 2 to 4 v ac if you spin the dizzy shaft [out of the car] to 100v ac spinning full bore in the engine.
I'll upload some scope patterns, you can only work on these things with a scope---[that's what stuffs our EH blokes] even then you have to know what you're looking at.
5. Module and wiring, and here's a trap --if by chance over the years somebody has managed to plug the cable from dizzy to module back to front--[remember any thing is possible!] or have cut and joined the 2 wires reversed,or if the permanent reluctor magnets get reversed polarity
The the firing of the module would then be on the falling edge of the AC wave instead of the rising edge,this would cause the module to be completely scrambled ,and cook up eventually ,you would have to ask one of the boffins about that!It would run but for how long? The dwell would work in reverse.Or just hang up.
So the module must fire on the rising ramp of the wave.This controls the dwell time.
Also there is light screen over the dizzy to module lead,I haven't bothered to have a good look at one,but I'll bet its earthed one end and acts as a ground loop screen,it would be good fun finding an intermittent misfire caused by a module getting stray spikes!
This is a rough and ready article no mention of cracked dizzy caps coil towers so on,just an indication of why a no start needs some one with a scope and able to use it--it saves you from guessing and from buying heaps of stuff you don't need.And rule one tricky bit out.If you have spark move on.
I also have the ECU scope patterns but if you are in that deep you would have a rare one
Made mistake,the earthing ferrel is on the Holden hybrid module ,505 is in the plugin cable - sorry .
broomy
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