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Bosch Blue coil on a 2.1DJ engine?
Posted: 04 Jan 2007, 21:20
by veedweeb
I've got a brand new Bosch blue coil that was destined for my Beetle engined Sandrail, and I'm just wondering if there's any reason I can't fit it to my Caravelle?
The 'velle is a 2.1 DJ engine.
Any thoughts?
Posted: 04 Jan 2007, 22:14
by Simon Baxter
Don't do it.
Well, you can if you want a worse spark, less power and the chance of destroying your ignition amplifier.
Posted: 05 Jan 2007, 09:06
by veedweeb
Fair enough!
I've replaced everything else except the coil, then I spotted the Blue coil in my garage and was just wondering if it could be used.
I'll leave it then. Thanks

Posted: 05 Jan 2007, 10:12
by ghost123uk
Is there a simple way of determining which coil is the correct type ?
They seem to change around 85 86 iirc.
I think my motor is the later type (plastic stat housing etc) but as it is an 86 registered it is "on the change" - for instance the HT lead set from GSF (pin type dissy cap) had the wrong end on the coil connector (I modded it easily enough, but it made me wonder if I have the correct coil fitted)
Posted: 05 Jan 2007, 17:55
by Simon Baxter
But a Bosch Blue Coil is for point ignition (CB) and not transistorised ignition systems as per WBX.
Posted: 05 Jan 2007, 19:47
by Aidan
part number will tell which one it is - stamped into the bottom of the coil iirc and chassis number will tell you which one you should have. Failing that it is possible to check the internal resistances to determine which one it is.
Posted: 08 Jan 2007, 12:31
by ghost123uk
So basically there are just 2 types, one for points and one for transistorised - Yes ?
Posted: 08 Jan 2007, 18:02
by Simon Baxter
ghost123uk wrote:So basically there are just 2 types, one for points and one for transistorised - Yes ?
Sort of.
A ignition coil is designed for the rest of the system.
That's why there are more than 2 types of ignition coil!
It would be nice to either have "this" or "That" for every manufacturer, but that simply ain't the case.
Theres loads of factors to take into account, spark plugs, gaps, leads, switching etc...
If you need a coil for an engine, get the correct one of the resistance of the primary may screw up whatever is switching the coil, or if the secondry is different then you aren't going to get the voltage at the spark plug that the system has been designed for..
Then theres ballast resistors..
On a T3, there are early and late coils as all are electronic ignition.
You should never put electronic ignition coils on points ignitions systems or vise versa, damage to coil/condenser/amp etc will ensue.
Posted: 09 Jan 2007, 09:47
by ghost123uk
Simon Baxter wrote:
On a T3, there are early and late coils as all are electronic ignition.
You should never put electronic ignition coils on points ignitions systems or vise versa, damage to coil/condenser/amp etc will ensue.
Thanks Simon
Err - sorry to labour the point ( no pun intended, I think ) and I hope you ain't muttering things under your breath, but...
If one has a van that was made in 85 / 86 ( the changer over from "MKI" to "MKII" ) or, as in my case, the engine bay is a right mongrel of later and earlier bits, is there a way of knowing which of the 2 types of electronically fired coils I should be using ?
I do have a good reason for asking btw...