Citroen XM Forum

Hi Guys.

Having fun at present with daughter's 1.8 Xantia and I think, but can't be certain, it's the coil pack starting to break down. According to the parts list, it's the same piece on the Mk1 injection 2.0 XM. So -- wondered if anyone has a known good one sitting on a shelf they would like to part with ?

Mike.

Hi Mike

Ive got a coil pack but are you sure it isnt the amp thats playing up?
unfortunatly im all boxed up and busy getting the new house ready to move into next week so im struggling to find the time to find the bits (ive no idea where ive put everything just now ).
You could pm Robert as he is breaking his onyx which has the same ignition components as some of the other Bosch injected N/A 2.0 engines, in fact i think i sent him my spare amp for it.
The post is here http://www.club-xm.co.uk/forum/viewtopic.php?f=11&t=858

Good luck
D

Mike,

PM sent.

Robert

I agree with Dean, I'd bet on the amplifier rather that the coil pack. Fortunately they're a common part, relatively cheap (£35ish) and easy to change .

Derek

Hi Guys.

Thanks for the replies (Robert -- have PMed you back, thanks)

I'm a little confused here -- I thought these non-moving dissy packs were a self contained item ? Main symptom, checked with an old fashioned timing lamp, is an intermittent, weak to non-existent spark on two cylinders and a full blooded, consistent spark on the other two. Wouldn't a failing amp impinge equally or randomly on all of them ? Anyway, from a belt and braces point of view, where does the amp live ? Should add, incidentally, I have trried new leads and so forth.

Mike.

It depends on what is happening.
If the engine is distributorless it will be using wasted spark technology, where two cylinders fire of each coil, if it has a distributor it will fire all four cylinders.
Most wasted spark technology uses the engine ECU to fire the coil, whereas single coil types use the amp which is usually mounted on the side of the distributor.
All the amp or ECU do is short the coil Gnd connection to Gnd to energise the coil, hence a coil can be tested without an amp or ECU. To test the output of the coil you really need a little caliper gauge, but a screwdriver jammed into the plug connection and held away from Gnd will do. You need a minimum of 15Kv so look for a spark of ~20mm+

Hi Mike

If you are getting two cylinders playing around then it will be one of the coils breaking down in the coilpack, the amp is a small flat black box and is usualy mounted away from the heat of the engine like on the side of the battery tray for example, it will have Bosch writen on it and has a single row plug on the side of it with about 7 wires coming out of it.

Good luck with it anyway.

D

i got a spare coil pack off my dads zant ,its a big plastic affair with the plug caps built in,,,after fitting a new one, only to find it was the crank sensor (maybee check that first)

Hi Terry

Robert is sending me a pack, so if it turns out not to be that, the sensor will be next on my list. Again, though, I would have expected a failing sensor to impinge on all cylinders, not just two.

Mike.