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Camilo,

Not setting the points gap - using the points opening to time the spark to the crank

.

The vernier will not take out a 20 degree error only a few degrees - its for fine tuning..

And the pinking in Ian's method will only be heard when you are driving and accelerating at low rpm, say 1000-1500rpm, flooring the throttle.

 

Another way of getting the timing roughly right is to run the warmed-up engine at tickover and turn the disy slowly to and fro maybe 1 cm at the rim and relclamp it when the tickover rpm are highest. Beware high voltage shocks and dont do it with any heart condition ! Then use Ians method.

 

Peter

Edited by Peter Cobbold
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Camilo,

 

The spark happens at the exact time that the points open - don't ask why, just accept it happens. So, with the rotor arm pointing towards number one cylinder and the points just about to open, the engine needs to be at the top of its compression stroke - TDC. Well 4 degs before actually.

 

Your fan pulley (assuming it hasn't been dismantled and reassembled wrongly) has a mark for TDC which needs to be aligned with the pointer on the timing chain cover when the engine sparks.

 

Rgds Ian

 

PS if you are really stuck and you have an Apple device we can do a FaceTime early next week.

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Hi Ian

 

I had a few disasters, enough to teach me something, so, I am confident that I will sort it out. My strobe seems to be faulty and I intend to follow your advice using the vernier to see where I get. But after, I have to go back to the test light as discussed in http://www.tr-register.co.uk/forums/index.php?/topic/63308-timing-final-straight/ (#20). Unfortunately, it did not work first time because I had my earth in the wrong place if I wanted to follow Macy's instructions.

 

See Rob's comment in http://www.tr-register.co.uk/forums/index.php?/topic/63398-timing-disaster/ (#2)

 

What I need to know now is where to connect the clip at the other end. I understand that it should be a good earth, but in my ignorance about electricity I want to make sure that it means attaching it to a metal surface anywhere on the car. Could you give me an idea of exactly where before I set the car on fire...?

 

Thanks

 

Camilo

Edited by qim
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Camilo,

 

I would urge you to try to find a garage familiar with classic cars, somewhere within a reasonable distance from Oeiras so that you can get this problem, and some of the others you have discussed previously, properly resolved.

 

I fear that you may continue to suffer problems with your car if you continue along your current path.

 

Apologies for these direct, and rather blunt words. I hope you take them in the helpful way I mean them to be received.

 

David

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Hi David

 

Thank you for the advice, but there are two reasons why I am insisting on this path:

 

There are no experts anywhere around. I have the car for 40 years and the only time it worked well was when I serviced and tuned the car myself after buying it.

 

Also, messing around with the car as I am doing now became a hobby, and I am more than capable of sorting things out, like I sorted out the carbs AND managed to get the timing right simply by sight. My current "problem" is just about finding out the "correct" way of setting the timing, which is wrong now because I thought it was a good idea to have a local garage use the sophisticated tuning equipment made by Bosch.

 

All I need now is the answer to the question in my last post: where do I clip my test light to obtain a good earth? I am asking this, not because I don't know, but because I want to make absolutely sure I don't do something stupid, like attaching it to the wrong side of the battery and blowing up half the car! I expect any solid metal surface (not the battery) is the answer, but I would be grateful for a confirmation. I'm afraid that at 71 and with memory problems, checking and rechecking before I lock the front door when I go away became a necessity for which I need a check-list...

 

Regards

Edited by qim
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If your car is positive earth, you can attach to the terminal marked with plus on the battery. That way you will definitely get a good earth. If you haven't changed things it will have come from the factory positive earth. If you have had an alternator fitted sometime in the past, it will be negative earth so use the other terminal on the battery.

 

If your leads aren't long enough to reach the battery, anywhere on the car body or chassis but make sure you have clean metal. On my car I put a tag on the connection for the radiator stay on the LHS of the vehicle specifically so that I could attach a test lamp when I was setting the timing.

 

As a final point, you don't have to use a test lamp to check when the points are opening. Place a cigarette paper between points and gently tug it while turning the dizzy. Then nudge the dizzy back a bit from the point at which the ciggy paper is released. And remember, it's the points just opening you want, not just closing.

 

Rgds Ian

Edited by Ian Vincent
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Hi Ian

 

many thanks- I learned something again!

 

Cigarrette +aper: I'll have to take up smoking, though...

 

More important: i would have made a bad mistake by attaching the test lamp to a painted metal surface.

 

My car still has the dynamo but has been converted to negative earth (the battery Minus terminal attaches to the body and that's where the battery cutting switch is located on the inside).

So, I will use the negative terminal of the battery and take up smoking! I will certainly try the cig paper!

 

Place a cigarette paper between points and gently tug it while turning the dizzy. Then nudge the dizzy back a bit from the point at which the ciggy paper is released. And remember, it's the points just opening you want, not just closing.

 

 

Instead of "nudge the dizzy back a bit" could I just leave it there and use the vernier to advance by 4º? (or is it retard?

 

I just don't understand why you mention "tug". I would think that with the points closed the paper will stay in place until they start opening and the paper falls. Why tugging it?

 

Many thnaks Ian

Edited by qim
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You want the points to be just opening Camillo - if they are far enough open for the paper to just fall out then you have gone too far. Actually with all respect to Ian, I would stick with the lamp method as it is considerably more positive and very little more trouble.

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We need to agree what the timing setting that you are trying to set should be as this thread seems to be turning up conflicting information.

The workshop manual specifies 4 degrees btdc static (24 degrees max with 10 degree cam) but that was for the leaded 4 star available when the car was new and is going to be way too retarded for modern fuels.

Modern unleaded fuel will require a setting close to 12 degrees, 32 degrees maximum.

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I have just come back from the car. Before touching the timing I decided to take the plugs out. As you may recall after tuning the carbs and running the car for a good 600kms the plugs were perfect: brownish colour.

 

Now they are with a black film on them. From what I learned in this and other threads it seems that the mixture is not being exploded fully, which accounts for loss of power and suggests that the spark is happening too late: retarded. is that right?

 

I also took a picture of the rotor after lining up the timing mark with the timing pointer. The metal part of the rotor seems to be pointing tpwards nº 4 lead as it comes from the dizzzy cap. I believe this is right, right?

post-14128-0-01759900-1506158113_thumb.jpg

Edited by qim
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We need to agree what the timing setting that you are trying to set should be as this thread seems to be turning up conflicting information.

The workshop manual specifies 4 degrees btdc static (24 degrees max with 10 degree cam) but that was for the leaded 4 star available when the car was new and is going to be way too retarded for modern fuels.

Modern unleaded fuel will require a setting close to 12 degrees, 32 degrees maximum.

 

Hi Andrew

 

Missed your post. When I first used the strobe it came up with 24º and the car ran well. Does this tie up with your "24 degrees max" which I don't quite understand. Is this 24º not static at tickover? What do you mean by "maximum"?

Edited by qim
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Your picture shows the distributor at TDC on no4 cylinder. Another complete turn of the crankshaft should see it at TDC on no1.

Your timing changes as the revs rise the rate of rise being controlled by the distributor springs. The timing will start at a static advance and rise to a maximum by the time the revs reach 2500 to 3000rpm. The maximum span between the two is limited by a rotating plate with a stop in the distributor under the points mounting plate. The plate will be stamped with the maximum advance which I would expect to be 10 degrees in your case.

The situation is slightly complicated by the fact that distributor advance is half crankshaft advance as the distributor turns at half crankshaft speed.

You need an advance around 32degrees above 2500-3000 rpm for modern unleaded fuel so given that a 10 degree distributor plate will give you 20 degrees advance from its minimum(static) position you will require a static setting of 32-20=12 degrees.

This will vary a bit, but not by much, depending on the spec of you engine.

Luckily standard or lightly tuned TR engines are fairly tolerant to timing inaccuracy so anywhere from 8-12 degrees static 28-32 degrees maximum should see you running.

Edited by Drewmotty
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Thank you Andrew for the comprehensive explanation.

 

I have just taken the car for short drive, aftar advancing the vernier by about 40 clicks (4º?) and the first impression was that it backfired a couple of times, which it did not do before. However, the "before" was in warmer temperatures (say 24º or more) while this morning may be a bit cooler. As before I don't use the choke once I get the car up the ramp and out of the garage.

 

Also, the car did not pink.

 

Referring to my question above

 

I have just come back from the car. Before touching the timing I decided to take the plugs out. As you may recall after tuning the carbs and running the car for a good 600kms the plugs were perfect: brownish colour.

Now they are with a black film on them. From what I learned in this and other threads it seems that the mixture is not being exploded fully, which accounts for loss of power and suggests that the spark is happening too late: retarded. is that right?

 

 

Does all this (plugs and backfiring) point to a retarded timing?

Edited by qim
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Hi

 

I now know what to do but am trying to understand what is happening first.

 

I used the strobe just to see where the timing mark is and how it differs from where it was when the car was running well.

 

Before, looking down the car from the front it was more or less an inch to the left of the pointer. Now, it is exactly where the pointer is. I understand that the angle to the left represents the advance, is that correct?

 

Which confirms again that the timing is way too retarded. Could you confirm my opinion and also that of the previous post, please?

Edited by qim
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Hi

 

I now know what to do but am trying to understand what is happening first.

 

I used the strobe just to see where the timing mark is and how it differs from where it was when the car was running well.

 

Before, looking down the car from the front it was more or less an inch to the left of the pointer. Now, it is exactly where the pointer is. I understand that the angle to the left represents the advance, is that correct?

 

Which confirms again that the timing is way too retarded. Could you confirm my opinion and also that of the previous post, please?

Yes the crank rotates clockwise so if it flashes to your left of the pointer the spark is occurring before TDC. Moving the flash more to your left will add advance.Moving the flash closer to the ponter is retarding the spark. If the flash occurs after the mark has passed the pointer the spark is AfterTDC.

All the above assumes the strobe flashes when #1 plug fires. Does it ??

Peter

Edited by Peter Cobbold
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All the above assumes the strobe flashes when #1 plug fires. Does it ??

Peter

Hi Peter

 

No idea! How can I check? EDIT: the sensor is placed around the cable for #1 plug. Is that what you mean?

 

Anyway, I used the vernier to advance it another 4º (around 40 clicks) and it started to run better. Then, I stopped and added another 2º. It is running quite well except that it heats up when I stop, faster than it did before. It still has not pinked, so tomorrow I am going to advance it further with the vernier. Altogether I advanced by over 10º today

 

Th strange thing is that my strobe gun (which I believe is useless) now shows 60º at tickover! Before I messed around with the dizzy and the car ran well it was 24º.

Edited by qim
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Just out of interest Camilo, what make and model is your strobe?

 

Rgds Ian

 

PS it sounds like you are getting on the right track. Don't touch the carbs while you are doing all of this, from what you said earlier they are properly adjusted, the black will be because you have had the car idling a lot. Once you get the car running well and go on a another good run they will go back to the correct colour.

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Hi Tom

 

I understood that it makes no difference if rotor is pointing to nº 1 or nº4 . What is the consequence of each? Are you saying that the sensor of the strobe should be hanging on nº4 lead?

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Hi

 

The car is going to the paint shop tomorrow to correct a few minor blemishes. I will not have time to try until next weekend, when I will try.

 

But, what could be the reason for the dizzy being like that?

 

I took the car out again and other than a couple of backfires when I left the garage without choke (engine cold) it worked quite well. In any case, I decided to adbance it a further 20 clicks, and I am now wondering about the 24º that my gun showed when I first tried it.

 

As I wrote, when I lost confidence in my strobe gun I took it to my electrician who used a Bosch huge machine. We decided to go by it and left the dizzy at 10º, which proved to be way too retarded. I have now advanced the dizzy by about 13/14º and the car seems quite good. It just so happens that the Bosch 10º plus my vernier advances of 14º total the 24º I got originally with the strobe before I messed up with the distributor.

 

Do you think there is a connection, and that the high angle may be due to the rotor pointing to nº 4?

 

Thanks

Edited by qim
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Hi Camilo ~

 

When I first got my 3A the distributor was 180 deg. out. I was able to time the engine using No. 4 lead

but I decided that I'd prefer the distributor to be set as per the workshop manual.

 

This meant removing the distributor and then turning the distributor drive in the block by 180 deg.

You have to lift the drive up to disengage it from the camshaft drive. You also have to turn the oil pump

drive 180 deg. because the slot in the drive is off-set.

This would then make the rotor arm point to No. 1 plug lead.

 

Tom.

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