Magnetti Marelli distributor cleaning

[andyps]

Having got my car to run, albeit not particularly smoothly and with the ignition light on I haven't managed to get it running again. I got a replacement voltage regulator from Omicron which I've fitted (and had previously had the alternator rebuilt) and as far as I can tell after checking with Omicron I have it wired in correctly.

The basic issue is that I rarely get a spark, and it is weak if there is one. I've gone through all the tests in my trusty old AA Book of the Car and after going through various earth connections because it could vary from working correctly to not doing without doing anything other than testing things light the LT wire from the coil to distributor on a couple of different earths where it might be correct, then not correct whichever way I tried earthing it. I now (maybe) have it isolated to a problem with the distributor potentially shorting, so think I need to take it out and clean everything to ensure that is resolved. My question is, how do I do this? I have a very poor quality spare distributor and can't easily see how it might come apart, in particular the plate on which the points and condenser mount. Also, it would be good to replace the LT wire to the coil but I'm not sure how to get the old one out, and to get the sleeve it passes through out.

All thoughts welcome!

[nistri]

Is the condenser OK? If this is poor, it might have also affected the coil operation as the coil can be energized effectively only with a good condenser. Before removing the distributor I would ensure that these two items are OK, Andrea

[nistri]

By the way, as indicated in another post of mine, there has been recently an epidemic of coil failures in Fulvias. Subframe vibrations and under bonnet heat have been suspected as the causative factors, Andrea

[Jai Sharma]

In the past I have found faulty condensers even if they were new, so don't rule out trying another or try the old one

[andyps]

I think the condenser in the car was pretty much unused as it looked very clean, I know there was some work done to get it running about 5 years ago before I bought it. I'll maybe swap back. The old coil had tested OK but I replaced it as a precaution. I've had a few other things to do this morning but will go and have a fiddle shortly. I've found the section in the repair shop manual about dismantling the distributor so I'll take a lot of photos and give it a go!

[D5177_55A]

Where the wire disappears through the body of the distributor, and is gripped by the copper grips either side, I put a couple of heat shrink sleeves over the top of one another to make sure the wire didn’t rub as it did before. Took me ages to figure out why the car was completely dead!

[andyps]

Where the wire disappears through the body of the distributor, and is gripped by the copper grips either side, I put a couple of heat shrink sleeves over the top of one another to make sure the wire didn’t rub as it did before. Took me ages to figure out why the car was completely dead!

Thanks for that, the copper grips aren't gripping mine, they slide along it fairly easily. Having had a play around again today I'm not convinced it is the distributor earthing, I'm at least getting a consistent spark now, just a weak one. I'd like to replace that wire but guess the only way is to put a new one in and then put a connector of the end of it - I can't see how to get the grommet type thing out which if passes through in the distributor body. I need to get some green wire though!

[lancialulu]

Check for a solid 12v at the coil. Dirty ignition switch and or fuse (7?) can combine to poor voltage esp when cranking. Battery is OK? Hotwire the coil to the battery and see if that makes a difference...

[andyps]

Check for a solid 12v at the coil. Dirty ignition switch and or fuse (7?) can combine to poor voltage esp when cranking. Battery is OK? Hotwire the coil to the battery and see if that makes a difference...

Thanks for the suggestions. I'm getting a good connection to the coil, battery failed in my multimeter though so haven't checked actual voltage but new battery in hand I will do this evening. All fuses cleaned up but next job is to clean the connections to them, the ignition switch is operating everything else and the car has run recently, just won't start at the moment. Battery is new and keeps getting recharged so that is fine. I can try the hotwire though! Just ordered new points and plugs, even though existing ones seem OK and are relatively recent.

You mentioned in the Facebook post I did about an earth from the gearbox bellhousing to the subframe/front spring housing - I can't see anything there on my car so if you can give me a little more detail about where it should be routed I can check again although as far as I can see there isn't anything.

[Charles Frodsham]

Are the plugs new? I know NGK plugs, once oiled, are near impossible to get working properly again.

[lancialulu]

You mentioned in the Facebook post I did about an earth from the gearbox bellhousing to the subframe/front spring housing - I can't see anything there on my car so if you can give me a little more detail about where it should be routed I can check again although as far as I can see there isn't anything.
[/quote]

Normally a thickish black wire from one of the bell housing bolts to the rhs (looking to the front of the car) front bolt holding the coil mounting bracket down.

[davidwheeler]

I know it is nice to keep things original but...   I have had trouble with weak spark on my 2CV rebuild despite points and coils being in good condition.  I fitted an electronic ignition pack but still weak spark.  However, this allowed me to go on to a high voltage coil as well - result!   The setup looks identical to the original too.  No longer do I have to churn for a minute or so to get it to go.   My Series II Sport came with electronic ignition and high voltage coil and, once I had sorted out the earth, performs faultlessly.    I see no problem in using modern technology where it is demonstrably superior (as in led side lights for example) and looks the same from the outside.

[andyps]

Are the plugs new? I know NGK plugs, once oiled, are near impossible to get working properly again.

I had heard that in relation to modern fuels, I've got new ones on the way from Omicron.

[andyps]

You mentioned in the Facebook post I did about an earth from the gearbox bellhousing to the subframe/front spring housing - I can't see anything there on my car so if you can give me a little more detail about where it should be routed I can check again although as far as I can see there isn't anything.

Normally a thickish black wire from one of the bell housing bolts to the rhs (looking to the front of the car) front bolt holding the coil mounting bracket down.
[/quote]

Definitely not got a lead there so will add one, it was too late last night to do it when I got chance, will be later in the week now as I'm working in the evening for the next couple of days.

[andyps]

I know it is nice to keep things original but...   I have had trouble with weak spark on my 2CV rebuild despite points and coils being in good condition.  I fitted an electronic ignition pack but still weak spark.  However, this allowed me to go on to a high voltage coil as well - result!   The setup looks identical to the original too.  No longer do I have to churn for a minute or so to get it to go.   My Series II Sport came with electronic ignition and high voltage coil and, once I had sorted out the earth, performs faultlessly.    I see no problem in using modern technology where it is demonstrably superior (as in led side lights for example) and looks the same from the outside.

I agree with you - I'm more concerned about a working car than one that is original so happy to swap to an electronic distributor but would like to get the car running first with any other issues solved. Only concern about an electronic distributor is that if it fails then that is it for that journey whereas it is possible to keep a spare set of points etc. to fit if needed at the roadside.