Classic Alfa Forums

Hi guys!

So my Nova engine is a 1.5 Ti, with a 1980 date code on the block, which should have had electronic ignition. However, when I got the engine it was minus the electronic ignition module/coil assembly (which is of course mounted in the battery tray area), only the Bosch JFUD-4 electronic distributor was in place, without any harness.

So I just replaced the electronic distributor with my 1978 Ti points unit and here we are, 22,000 miles later.

Recently I have repaired a Bosch CDI ignition box from a 1982 911SC, and apart from the number of cylinders, the magnetic reluctance pickup is virtually identical to the Alfa one. In fact, in researching possible replacements it turns out that the Montreal used a dual Bosch CDI set-up to fire the V8 (twin coil distributor).

Anyway, to test the repaired CDI box I dug out my electronic distributor and used it to trigger the CDI box. Works a treat. Which got me thinking it was high time I reinstated the electronic ignition on my engine.

Now, I have seen pictures of the Magneti Marelli Plex ignition module (it is a finned alloy casting with the coil bolted to it), and the inductive discharge switch module bolts to the heatsink underneath the coil.

My question is, does anyone have an example of the equivalent Bosch unit? The switching module is bigger than the Marelli one, 6-pins instead of 4. The part number for the Alfasud/Alfetta/116 Giulietta etc. is 0-227-100-123 and it is still readily available new for around £30.

Does the Bosch module fit the same finned heatsink as the Marelli unit? Or should I just make up my own heatsink out of 5mm alloy plate?

These little switching modules are interesting bits of kit - with a 36-1 crank wheel and sensor you could have 4 independent ignition channels, each with a dedicated coil, one for each plug. I always fancied having direct ignition on the Alfa boxer

Can anyone help?

Lauren

I have the Bosch ignition system with distributor fitted to my 1.5 green cloverleaf sprint.... is this the one you mean? Yes it's different to the marelli... the marelli from memory has a large alloy heatsink the coil sits on.... the Bosch doesn't... just an alloy plate, both the coil and ign amplifier are bolted to this.can send pics if it helps.?
Bosch has the green pick up lead as opposed to white marelli one.
Peter

Thanks Pete - a picture would be useful. I just need to get a feel for the size of the heatsink. Good to know it isn't a complicated finned thing, although I do like the look of the Marelli and I have also read that it has proved to be reliable.

Hi Lauren. I’ve got a bunch of Bosch coils and heat sinks with amps. If if you need one

Spacenut wrote:Thanks Pete - a picture would be useful. I just need to get a feel for the size of the heatsink. Good to know it isn't a complicated finned thing, although I do like the look of the Marelli and I have also read that it has proved to be reliable.

Back in the 90s.... I had my sprint with Webers and Bosch ignition.... my mate had a white 1.5qv with dellortos and the marelli set up....he had problems with his pick up lead!.. my Bosch system continues to be reliable 26 years on.. I recently got a spare coil, ign amp and pick up lead just in case but it's been good as gold.
Pete

Pete Jennings wrote:

Spacenut wrote:Thanks Pete - a picture would be useful. I just need to get a feel for the size of the heatsink. Good to know it isn't a complicated finned thing, although I do like the look of the Marelli and I have also read that it has proved to be reliable.

Back in the 90s.... I had my sprint with Webers and Bosch ignition.... my mate had a white 1.5qv with dellortos and the marelli set up....he had problems with his pick up lead!.. my Bosch system continues to be reliable 26 years on.. I recently got a spare coil, ign amp and pick up lead just in case but it's been good as gold.
Pete

I had a 33 with the marelli and also had a problem with the lead from the distributor. The insulation on the cable deteriorated and caused a intermittent fault which took me an age to find. I've never had a problem with the bosch.

Thanks guys - it's good to know that the Bosch system is as good (if not better) than the Marelli. And thanks for the offer Lou, much appreciated, but I have an ulterior motive for putting together my own system - I may be able to replace the CDI in my friends 911 with a more reliable inductive discharge ignition based on the Bosch module and using the CDI casing as a heatsink. If I hook up the internal module connectors to the original 6-pin connector we should be able to use the factory harness and simply change the coil.

Secondhand Bosch CDI boxes (untested) are selling for £400, refurbished £600 and replacements (with programmable advance curves) are retailing for £900. Using the factory Bosch distributor but substituting the inductive module and a new Bosch blue coil will come in at around £60. I know the CDI is supposed to give a stronger spark, but my friends unit is 37 years old and is looking decidedly flaky inside...

Thanks for the picture Pete - really useful. The heatsink surface area is really only the size of the module and the coil bracket combined. I've got some thermal doubler plates in the garage that will do the job nicely. The key is to use lots of thermal grease between the module and the baseplate of course

Lauren

I had the Marelli system.....as the vac advance operated the moving plate, it bared the wires, causing a fault.

I've always used the Bosch system since, and never had a problem......

except the rotor arm burnt out once....now I always carry a spare, and they are still easily obtainable

.......easily available as the Bosch dissy was the same as a Ford I think

Thanks guys - I've been checking out my distributor (Bosch magnetic induction type) and the vacuum advance is in working order, as are the mechanical advance weights (although they are a bit sticky after years of inactivity).

I've found that the sensor terminals are 2.8mm, does anyone know what type of connector mates with this distributor? I've tried a Bosch injector plug which had the right pitch but the plastic moulding is different. There are some other 2-pin plugs about that might fit the bill, like the Durite Superseal, but I thought I would ask before spending any more money.

I can't imagine Bosch would design a unique plug for this distributor, however it could be obsolete so I am not getting my hopes up just yet.

Any advice would be gratefully received!

Lauren