Guys
I took the opportunity of some spare time over the weekend to carry out a ‘tune up’ of my S2 1300 Coupe, after recently returning it to the road. Although I did get the car running a great deal better, the exercise raised a few questions on the ignition timing.
Firstly, upon attempting to set the static advance to the 8degree mark as described in the owner’s manual, I found that this mark bares no relation to the actual position at which the car will run at. Therefore, is it possible that either the flywheel or distributor has been mounted incorrectly in the past? I believe the engine was rebuilt prior to my ownership.
Secondly, in the absence of any timing marks I set the engine up by trial and error slowly retarding the ignition to a point were the car does not ‘pink’ under load (using std 95 unleaded and valvemaster plus). Although the car seems to run well any advice would be appreciated
Many Thanks
Julian
Ignition timing
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Huib
Re: Ignition timing
The flywheel is bolted to the crankshaf with 5 or 6 M10 bolts. In addition there is a dowel to make sure it is always in the right position. Unless someone removed the dowel (very unlikely) it is not possible to mount the flywheel in a wrong position.
Does the TDC mark line up when piston 1 is at TDC?
When you stick the rear end of a digital calliper through plug hole #1 you can determine TDC very exactly.
The ignition mark is nearly 3 teeth ahead of the TDC mark.
It is possible to stick the ignition into the head with the rotor in any position. People sometimes do this and swap the cables to the plugs accordingly. But in the end, the spark has to come at a reasobale correct moment which is not too far from the ignition mark. If not the car would not run or run very badly.
I prefer to have everything standard as it makes fault finding much easier. When the TDC mark is lined up you still don't know if it is #1 or #4 which needs a spark. It could be either of the two. To find out if it is #1 or #4 you have to remove the rocker cover and feel the rockers of #1 and #4. If you can move the rockers of #1 just a bit, it means those valves are closed and #1 is ready to fire. If it is not #1 but #4 where you can move the rockers, turn the crankshaft 360 degrees. I use spanner 24 on the crankshaft pulley to do this.
If #1 is in firing position, stick the distributer in the head with the finger of the rotor pointing down or just past the vertical position. The capacitor is facing down and the points are at the upper part. Do a preliminary setting of the fixed advance and see it it results in a position of the clamps which allow the clamps to be put on the cap. Sometimes parts are in the way. If this happens to be the case you can pull the ignition out again and try a slightly different position. Sometimes it is convenient to pull off the teethed wheel at the bottom of the ignition and change its position 180 degrees.
You should also check the centrifugal advance mechanism. The weights should move freely. The small springs must be the correct types. One spring has two round eyes and works over the complete angle of movement. The other one has a round eye an a rectangular eye and works only on part of the angle. On S2/3 ignitions the center spindle is often a bit higher than the small plate where the two pins sit. Make sure your rotor is correct and not a version which touches the center spindle which would prevent free movement. If you turn the rotor clockwise by hand it should turn counterclockwise decisively when you release it.
Does the TDC mark line up when piston 1 is at TDC?
When you stick the rear end of a digital calliper through plug hole #1 you can determine TDC very exactly.
The ignition mark is nearly 3 teeth ahead of the TDC mark.
It is possible to stick the ignition into the head with the rotor in any position. People sometimes do this and swap the cables to the plugs accordingly. But in the end, the spark has to come at a reasobale correct moment which is not too far from the ignition mark. If not the car would not run or run very badly.
I prefer to have everything standard as it makes fault finding much easier. When the TDC mark is lined up you still don't know if it is #1 or #4 which needs a spark. It could be either of the two. To find out if it is #1 or #4 you have to remove the rocker cover and feel the rockers of #1 and #4. If you can move the rockers of #1 just a bit, it means those valves are closed and #1 is ready to fire. If it is not #1 but #4 where you can move the rockers, turn the crankshaft 360 degrees. I use spanner 24 on the crankshaft pulley to do this.
If #1 is in firing position, stick the distributer in the head with the finger of the rotor pointing down or just past the vertical position. The capacitor is facing down and the points are at the upper part. Do a preliminary setting of the fixed advance and see it it results in a position of the clamps which allow the clamps to be put on the cap. Sometimes parts are in the way. If this happens to be the case you can pull the ignition out again and try a slightly different position. Sometimes it is convenient to pull off the teethed wheel at the bottom of the ignition and change its position 180 degrees.
You should also check the centrifugal advance mechanism. The weights should move freely. The small springs must be the correct types. One spring has two round eyes and works over the complete angle of movement. The other one has a round eye an a rectangular eye and works only on part of the angle. On S2/3 ignitions the center spindle is often a bit higher than the small plate where the two pins sit. Make sure your rotor is correct and not a version which touches the center spindle which would prevent free movement. If you turn the rotor clockwise by hand it should turn counterclockwise decisively when you release it.
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Julian
Re: Ignition timing
Many Thanks for the good advice,
I will check these points out tonight
Thanks
Julian
I will check these points out tonight
Thanks
Julian
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P. de R. Leclercq
Re: Ignition timing
Huib has provided his usual thorough summary of everything you need to do.
I would just add that I would prefer 98-octane fuel for a Fulvia Coupé - I would think that 95 would be OK though for a S1 (not S) or a Berline.
Paul
I would just add that I would prefer 98-octane fuel for a Fulvia Coupé - I would think that 95 would be OK though for a S1 (not S) or a Berline.
Paul
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Huib
Re: Ignition timing
The 1.3S engines of my S3 coupe and the 1.3S engines I look after all run perfectly ok on 95 octane without any additives!
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P. de R. Leclercq
Re: Ignition timing
I am pretty sure that 95RON European fuel, normally with a MON of 85 will be OK in a S2 coupé, my previous message just expressed a preference, together with the "comfort" zone of knowing that (here in France anyway) most 98 RON fuel has a MON of 88 - better than most fuels available in England.
I would add that I think that 98 is esential for 1600s with their 10.5/1 compresion ratio.
Oh I long to find a secret supply of the wonderful five-star fuel we had in England in the 1970s. 101 RON and full of lovely lead!
Paul
I would add that I think that 98 is esential for 1600s with their 10.5/1 compresion ratio.
Oh I long to find a secret supply of the wonderful five-star fuel we had in England in the 1970s. 101 RON and full of lovely lead!
Paul
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Julian
Re: Ignition timing
Huib / Paul
Just a quick update,
I removed the distributor over the weekend and found that there was around 1mm float between the shaft and the body. Due to the cross cut gears on the drive this was causing around 10 degrees of movement at the rotor head. I made a new shim to take out the play and now the figure is down to around 3 degrees, purely due to the backlash in the drive gears.
I also inspected the weights on the advance which are worn but work ok. However you describe that "One spring has two round eyes and works over the complete angle of movement. The other one has a round eye and a rectangular eye and works only on part of the angle". On my car both weights appear to act equally over the same movement, any ideas?
Thanks
Julian
Just a quick update,
I removed the distributor over the weekend and found that there was around 1mm float between the shaft and the body. Due to the cross cut gears on the drive this was causing around 10 degrees of movement at the rotor head. I made a new shim to take out the play and now the figure is down to around 3 degrees, purely due to the backlash in the drive gears.
I also inspected the weights on the advance which are worn but work ok. However you describe that "One spring has two round eyes and works over the complete angle of movement. The other one has a round eye and a rectangular eye and works only on part of the angle". On my car both weights appear to act equally over the same movement, any ideas?
Thanks
Julian
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P. de R. Leclercq
Re: Ignition timing
Julian, that was Huib who wrote about the springs. The spring with the rectangular hole, as I recall, is stronger than the other; I expect it is designed to control the advance curve at higher revolutions.
Over to Huib!
Paul
Over to Huib!
Paul
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Huib
Re: Ignition timing
The weights are identical.
Just the springs which provide the counterforce are different from each other.
If you look at the diagram of the ignition you will note that it has a two slope characteristic. At about 1800 crankshaft rpm there is a breakpoint.
The one with the two round eyes works over the full range. The one with the long eye cuts in at about the above 1800 rpm and reduces the slope as the two springs are now both working. At about 3200 rpm there is no further advance as the advance is hard limited by the pin and the hole at the top.
Note that there should be a washer under the rotor head (the part with the cams and the mounting base for the rotor). It keeps that part at the right height from the base and thus at the correct position for the contacts in the cap. I don't remember the exact thickness of that washer but it is around 1 mm and thus much thicker than the shims at the bottom which do sometimes also add up to nearly 1mm. Since you mention 1mm I was just thinking maybe that washer under the rotor head went missing.
Just the springs which provide the counterforce are different from each other.
If you look at the diagram of the ignition you will note that it has a two slope characteristic. At about 1800 crankshaft rpm there is a breakpoint.
The one with the two round eyes works over the full range. The one with the long eye cuts in at about the above 1800 rpm and reduces the slope as the two springs are now both working. At about 3200 rpm there is no further advance as the advance is hard limited by the pin and the hole at the top.
Note that there should be a washer under the rotor head (the part with the cams and the mounting base for the rotor). It keeps that part at the right height from the base and thus at the correct position for the contacts in the cap. I don't remember the exact thickness of that washer but it is around 1 mm and thus much thicker than the shims at the bottom which do sometimes also add up to nearly 1mm. Since you mention 1mm I was just thinking maybe that washer under the rotor head went missing.
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Julian
Re: Ignition timing
Huib
Now I understand the principle of the advance springs.
The small washer under the cams was in place so I guess the wear was in the base of the body. However everthing lines up ok with the new shim and the play has been reduced to a minimum.
Thanks
Julian
Now I understand the principle of the advance springs.
The small washer under the cams was in place so I guess the wear was in the base of the body. However everthing lines up ok with the new shim and the play has been reduced to a minimum.
Thanks
Julian