Hello!
I have been forced by circumstances (my wife's ZX has a breaking problem so he has got my Astra ;-) ) to get the XM out of the garage although it still has an intermittent problem with, apparently, Lambda sensor wiring (although I worked about 10 hours on the cabling, doing both static and dynamic checkings and could not locate the culprit). As a check, I did a 100km 'pleasure trip' (I had holiday yesterday) but the car worked fine.
But while looking at that trouble, I found a suspicious thing: there is a capacitor, marked as component 270 on my XM (92' 2.0 Turbo CT) schematics, which is approximately an 1 inch x 0.75 inch black box, marked as FACON 2022 2.2uF. Well, it was hanging on its wire (positive connection) so the negative side of it, which should be connected to car chassis, is just missing (I think it should be a metal tab). So capacitor is not doing its work which, located as it is in the ignition coil, could cause other troubles due to parasitic spikes entering the car's ECUs.
I have found this description on the Net about what such a capacitor does:
"Capacitor (Condenser) - The capacitor performs several functions. It prevents the points from arcing and prevents coil insulation breakdown by limiting the rate of voltage rise at the points. It's primary function is to provide for a rapid decay of the primary coil current. The capacitor also "third-harmonic" tunes the coil, raising the peak output voltage and increasing the secondary voltage rise time. This increases the efficiency and the amount of energy transferred to the spark plugs. If the coil secondary voltage rises too quickly, excessive high frequency energy is produced. This energy is then lost into the air-waves by electro-magnetic radiation from the ignition wiring instead of going to the spark plugs where we would like it to go. Voltage rise time should be more than 10 microseconds; a 50-microsecond rise time is OK. Conventional systems have a typical rise time of about 100 microseconds"
So, please, could somebody help me locating one?. I am afraid my XM could be damaged if it continues working without it. I went to my local Citroën dealer and they said that part was not available sepparately and I should buy all the ignition coil wiring assembly (!). I don't trust that so, if it is available as a part, a Citroën part number would help me a lot. Does anybody know it?
I could also fit a used one, if somebody has it available.
Thanks for your help!
Regards,
JOSE
I have been forced by circumstances (my wife's ZX has a breaking problem so he has got my Astra ;-) ) to get the XM out of the garage although it still has an intermittent problem with, apparently, Lambda sensor wiring (although I worked about 10 hours on the cabling, doing both static and dynamic checkings and could not locate the culprit). As a check, I did a 100km 'pleasure trip' (I had holiday yesterday) but the car worked fine.
But while looking at that trouble, I found a suspicious thing: there is a capacitor, marked as component 270 on my XM (92' 2.0 Turbo CT) schematics, which is approximately an 1 inch x 0.75 inch black box, marked as FACON 2022 2.2uF. Well, it was hanging on its wire (positive connection) so the negative side of it, which should be connected to car chassis, is just missing (I think it should be a metal tab). So capacitor is not doing its work which, located as it is in the ignition coil, could cause other troubles due to parasitic spikes entering the car's ECUs.
I have found this description on the Net about what such a capacitor does:
"Capacitor (Condenser) - The capacitor performs several functions. It prevents the points from arcing and prevents coil insulation breakdown by limiting the rate of voltage rise at the points. It's primary function is to provide for a rapid decay of the primary coil current. The capacitor also "third-harmonic" tunes the coil, raising the peak output voltage and increasing the secondary voltage rise time. This increases the efficiency and the amount of energy transferred to the spark plugs. If the coil secondary voltage rises too quickly, excessive high frequency energy is produced. This energy is then lost into the air-waves by electro-magnetic radiation from the ignition wiring instead of going to the spark plugs where we would like it to go. Voltage rise time should be more than 10 microseconds; a 50-microsecond rise time is OK. Conventional systems have a typical rise time of about 100 microseconds"
So, please, could somebody help me locating one?. I am afraid my XM could be damaged if it continues working without it. I went to my local Citroën dealer and they said that part was not available sepparately and I should buy all the ignition coil wiring assembly (!). I don't trust that so, if it is available as a part, a Citroën part number would help me a lot. Does anybody know it?
I could also fit a used one, if somebody has it available.
Thanks for your help!
Regards,
JOSE
