Car not starting

[David B2]

My point about distributor position was an indication that 'timing' could have been incorrect which owner advised he hadn't yet checked.

David B

[Kiwifrog]

14 hours ago, David B2 said:

My point about distributor position was an indication that 'timing' could have been incorrect which owner advised he hadn't yet checked.

David B

David I understand and apologise if any offence occurred.

I keep forgetting that to the younger generation distributors are black magic, I worked once with a mechanic a couple of years ago in his early 40’s who had always worked for a main dealer and had no idea how a distributor worked or how to adjust a carburettor, I had been asked by the owner of the garage who was in the same car club as me to help him service ans setup a spitfire 

Edited December 19, 2024 by Kiwifrog

[Phil Read]

I have been following this topic with interest. It would seem the car was running ok till the breakdown. To my mind this would eliminate ignition timing. Fitting a new set of points and setting the correct gap would not change the timing enough to stop the car starting and running. My recent experiences with classic cars not starting or not running properly has been with capacitors and coils, although in one case it proved to be the voltage regulator.

[stuart]

15 hours ago, David B2 said:

My point about distributor position was an indication that 'timing' could have been incorrect which owner advised he hadn't yet checked.

David B

Timing was correct, distributor is frozen in position so cannot be moved anyway.

Stuart.

[Besalu]

a mechanic friend of a friend came around and adjusted the points gap and the car started first time and is now running well

I was positive i set the 15 thou gap correctly but obviously it was too tight. simple little error. At least i know now!

Stuart is correct, the dizzy is frozen in place and i cannot remove it from the pedestal. I have replaced the points, condensor and link wire (all parts from Distributor Doctor). I have also put a new rotor arm and changed the plugs.

At some point the dizzy and pedestal will have to come off together and a new dizzy fitted. At this point not sure whether to stick with points or go electronic but that decision is for another day....

Thank you everyone for all the input. What a great forum this is!

[John Morrison]

Hi Richard, 

always a steep learning curve, these old girls, congrats on getting her

running well again.

I would stick with points, I have, but in my box of stuff always in the car, 

is a spare distributor baseplate complete with points and a condenser, tried in the comfort

or the garage, and then ready whenever they are needed.

Other thing I would suggest you buy is a multimeter, not expensive these days, £20 ish?

that has a dwell measurement, then whenever you change/clean/set points you can confirm

with the meter.

You have my contact info, if ever you want a one to one.

ATB for the festivities.

John.

[keith1948]

Back in the 1960's I remember my dad's Triumph Vitesse once got slower and slower and eventually stopped on the A1 near Baldock. The man from the AA arrived and adjusted the points to open the gap a bit more and problem solved. I now use a dwell meter rather than feeler gauge to set the points. It is surprising how a couple of thou can make all the difference.

Keith

[David B2]

Have seen the benefits of dwell and see it would be useful to me.  But..... I have very good electrical multimeter that doesn't need replacing for something that I might only use very occasionally.

Question. Can I set up and measure DWELL degrees on a this 'normal' multimeter without the specific dwell function.

Many thanks, David

PS. Done want to spend £30- £40 on a dwell meter whilst my eyesight and feeler gauges are still OK.

Edited December 21, 2024 by David B2

[RobH]

13 hours ago, David B2 said:

Question. Can I set up and measure DWELL degrees on a this 'normal' multimeter without the specific dwell function.

It is possible to measure dwell with a multimeter but it needs some additional electronic circuitry David.  It is fairly easy to arrange with an old-fashioned analogue moving-coil multimeter but rather complicated with a digital one.   That is because a mechanical meter can average a fluctuating reading by virtue of the way it works but a digital one cannot. 

There is information on the web on suitable circuits but unless you are an electronics enthusiast it is really not feasible.  

 

 

[David B2]

Thanks Rob. Have done some searching. 

I've been setting points many years, initially using a fag packet and then the more sophisticated feeler gauge method when they became available. Have still got this in my tool box. Note that car is performing OK so this is purely academic. 

However,  I have a Lovcum T28B that will measure duty cycle. I've searched the web and found some interesting methods to measure duty cycle then converting to dwell although my brain is now aching a bit but may come clearer (or not) when I connect up tomorrow.

David B

[RobH]

I have a distributor setting tool from the '70s which is convenient for gap adjustment.  It consists of a chromed ring with a wall thickness of about 2mm which fits over the cam lobes, and a feeler gauge which is the thickness of the ring plus 15 thou.   Using that you don't need to turn the engine to align the lobe with the heel of the points, you just open the points wide by hand, slip the ring over the lobes and set the points gap using the thick feeler gauge.  When you remove the ring the points are at the correct 15 thou setting. 

 

That is a good meter you have - not many affordable ones have the duty-cycle function. 

The confusing bit when setting dwell using % duty cycle, is translating from degrees to percent.  On a 4 cylinder engine the cam lobes are 90 degrees apart so for 60 degrees dwell the waveform is 60/90  closed and 30/90 open,  so 60 degrees dwell = 66.6% of the waveform. 

 

 

Edited December 22, 2024 by RobH

[John McCormack]

On 12/19/2024 at 9:11 PM, Kiwifrog said:

David I understand and apologise if any offence occurred.

I keep forgetting that to the younger generation distributors are black magic, I worked once with a mechanic a couple of years ago in his early 40’s who had always worked for a main dealer and had no idea how a distributor worked or how to adjust a carburettor, I had been asked by the owner of the garage who was in the same car club as me to help him service ans setup a spitfire 

In Australia they stopped teaching carburetors, distributors and such things on mechanic's apprenticeships about 25 years ago. Understandably, cars hadn't been built with them since the late 80s early 90s.

This is the biggest threat to classic car use here, if the owner can't do the maintenance there are not enough tradesman around who can/will do it. 

I've had a few glitches with the electrics on my TR4. On Friday I rang three auto electricians near me and not one of them had anybody who could help. 

[tim hunt]

On 12/21/2024 at 1:02 PM, keith1948 said:

Back in the 1960's I remember my dad's Triumph Vitesse once got slower and slower and eventually stopped on the A1 near Baldock. The man from the AA arrived and adjusted the points to open the gap a bit more and problem solved. I now use a dwell meter rather than feeler gauge to set the points. It is surprising how a couple of thou can make all the difference.

Keith

+1. I once had the same problem with a  Hertz hire car (a Mk2 Cortina, which rather dates me!). It gradually petered out on the A1 near Leeds. I was fortunately able to coast to a halt in a lay-by and on investigation found that the points had closed up completely. I had an adequate small screwdriver on the ring with my house keys, found a discarded fag packet in a waste bin that allowed me to set a suitable gap and was soon on my way.

Tim

[RAHTR4]

14 hours ago, RobH said:

I have a distributor setting tool from the '70s which is convenient for gap adjustment.  It consists of a chromed ring with a wall thickness of about 2mm which fits over the cam lobes, and a feeler gauge which is the thickness of the ring plus 15 thou.   Using that you don't need to turn the engine to align the lobe with the heel of the points, you just open the points wide by hand, slip the ring over the lobes and set the points gap using the thick feeler gauge.  When you remove the ring the points are at the correct 15 thou setting. 

 

That is a good meter you have - not many affordable ones have the duty-cycle function. 

The confusing bit when setting dwell using % duty cycle, is translating from degrees to percent.  On a 4 cylinder engine the cam lobes are 90 degrees apart so for 60 degrees dwell the waveform is 60/90  closed and 30/90 open,  so 60 degrees dwell = 66.6% of the waveform. 

 

 

Rob,

I totally agree a “Remax Contact Setting Gauge” is the best and simplest way to accurately  adjust the points.

They first appeared at the London Motor Show in December 1957 and were sold in a transparent tube with green cap and base – the green being the Remax company colour.

Regards, Richard

[keith1948]

I like the look of the Remax tool. Maybe I could make one since I don't think I'll find one on the internet. I like the way you can set the points without pushing the car backwards and forwards to try to get the setting on the heel of the cam.

Keith

[David B2]

23 hours ago, RAHTR4 said:

Rob,

I totally agree a “Remax Contact Setting Gauge” is the best and simplest way to accurately  adjust the points.

They first appeared at the London Motor Show in December 1957 and were sold in a transparent tube with green cap and base – the green being the Remax company colour.

Regards, Richard

Richard,

You must have a very tidy toolbox with not just the tool but the instructions in fully readable condition.   1957 and still with area telephone codes on the sheet. Wow.

David B

 

[Rayh]

On 12/22/2024 at 9:01 PM, RobH said:

I have a distributor setting tool from the '70s which is convenient for gap adjustment.  It consists of a chromed ring with a wall thickness of about 2mm which fits over the cam lobes, and a feeler gauge which is the thickness of the ring plus 15 thou.   Using that you don't need to turn the engine to align the lobe with the heel of the points, you just open the points wide by hand, slip the ring over the lobes and set the points gap using the thick feeler gauge.  When you remove the ring the points are at the correct 15 thou setting. 

 

That is a good meter you have - not many affordable ones have the duty-cycle function. 

The confusing bit when setting dwell using % duty cycle, is translating from degrees to percent.  On a 4 cylinder engine the cam lobes are 90 degrees apart so for 60 degrees dwell the waveform is 60/90  closed and 30/90 open,  so 60 degrees dwell = 66.6% of the waveform. 

 

 

Rob,

I’m a little late to this party, but think that the Remax setting tool would be a great addition to my box of tricks!
Would it be possible to give me the measurements of the tube (height, diameter & wall thickness) and thickness feeler gauges so that I could try to make one, please

 

Ray

[RobH]

Here y' go Ray, measured as accurately as I can:

outside diameter.   19.7 mm    (0.775 inch)  not critical- it just allows for spring

wall thickness.      0.43mm. (17 thou)

height.   25.4mm    (1 inch)

The cylinder is cut as you can see in the photos above, and is slightly springy so it grips over the cam lobes. 

now comes the odd bit - 

The '14/16' thou feeler is 0.93 mm thick (36 thou) , the '10/12' thou feeler is 0.8mm thick (32 thou)  so it isn't a straight arithmetical subtraction as you might have expected.  This is to account for the geometry of the points, because the heel of the points is not directly radially in line with the contact as shown below.     (This doesn't matter when you make the adjustment direct without the tool, of course)

If you are making one of these you might need to experiment with the feeler thickness until you get the setting correct. 

 

[Rayh]

Rob

Thanks for taking the trouble to measure. I will make the sleeve then hopefully should be able to determine the correct thickness of the feeler by using my dwell meter.

I’ll report back on the success (or otherwise!) of my attempt, once the Garage has warmed up a bit!
 

Ray

[Phil Read]

I used to teach apprentices and one of the difficulties with setting contacts is that you use "feeler" gauges. Trying to teach some one the correct "feel" when sliding the blade through the gap is quite difficult as we all feel differently.

[RobH]

That's true Phil but really accurate points gap setting isn't too critical in normal driving - it only makes a significant difference at high revs. What you are trying to achieve is a 'dwell' time which is long enough for the coil to achieve saturation with them closed, while also giving a suitable spark time when they are open.  At the kind of revs used in normal touring - say up to 4500rpm - there is enough time for both even if the points are set a thou' or two wrongly.  

 

[Phil Read]

1 hour ago, RobH said:

That's true Phil but really accurate points gap setting isn't too critical in normal driving - it only makes a significant difference at high revs. What you are trying to achieve is a 'dwell' time which is long enough for the coil to achieve saturation with them closed, while also giving a suitable spark time when they are open.  At the kind of revs used in normal touring - say up to 4500rpm - there is enough time for both even if the points are set a thou' or two wrongly.  

 

yep the cars always went on a Crypton motor scope afterwards to ensure dwell, timing etc was within parameters..

[BlueTR3A-5EKT]

Agree on the usefulness of setting points with dwell.

Years ago I took a summer job in the US that involved boat maintenance.      The first time  I was given the task of “Refresh the contacts dude on the speed boat”.  I set them with a feeler and was briskly pushed aside and watched the use of a dwell meter on the Mallory distributor fitted to the outrageous V8 motor.  My instructor assured me the motor would run like a “bag o’ ****” using them feeler gauges.  Simple job too   With the distributor sitting on top of the engine and fully accessible. Just crank the engine and adjust the points to get the correct dwell on the dial.  Then nip up the points screw and slap it all back together.   

When I went to Sears the following week I bought a dwell meter.    It got used on the boats, but I’ve not used it on TRs.  

[Ralph Whitaker]

This has just reminded me I have a dwell meter on the shelf in the garage somewhere . Having just converted my 3a back to a points distributor I will have to find it and dust it off. I think it is a Gunsons one i`ve had since the 70s.

Ralph

[james christie]

Ralph, why did you go back to points?

I was fettling a non starting MGA this week where it's nigh impossible to access the points and suggested to the owner he convert to Pertronix, which I've been running for 20 years on my 3A.

james