17 replies to this topic

[1293gt]

Hello all,

I have just tried wiring in my new (to me) Smiths RVI Tacho. I have points and so assumed all would be well but....

 

After the car running for about 5 mins it spluttered to a halt (rev counter seemed to work at 1k Revs but went down instead of up when I increased the revs.

 

Being concerned that the car had died I removed all the temp wiring but the car still fails to start. I did notice that the coil got quite warm so thought I may have cooked it. Tried with another coil and still the same result.

 

Any ideas please, I have +12v going to the coil and then the - terminal of the coil going to the Dizzy and I think that should be all that's required?

 

I do have a spark but it looks quite weak and it's not trying to start at all.....

 

TIA

[GraemeC]

Enough fuel?
Easy to run out without realising when your playing with something else

[miniGTS]

+12v from where on the tacho and -from where on the tacho?

[1293gt]

Hey GreameC,
Yep, plenty of fuel but I do know what you mean🤣
MiniGTS, I have removed the Tacho now but it still won't run.

[Ethel]

It's not ballasted ignition is it?

[1293gt]

Hi Ethel,

it's 12v to the coil so I don't think it is ballasted.

 

 1 thing I have noticed is that when the ignition is on, the the distributor cap removed I do not got any sparking when opening and closing the points which I would expect?

I do get a spark if I short the points out with my screwdriver so I'm now thinking points?

Could I have damaged to points somehow

Edited by 1293gt, 16 September 2024 - 12:48 PM.

[gazza82]

It is positive or negative earth? Connecting the coil connections the wrong way will lead to a poor spark.

[1293gt]

Hi Gazza82, it's negative earth. 
12v going to + on the coil and the - on the coil goes to the Dizzy.

Is there anything in the Dizzy I could have damaged?

 

What about bypassing the loom any running +12v to the + side of the coil and running the - side of the coil to earth/negative o the battery terminals.

Edited by 1293gt, 16 September 2024 - 08:01 PM.

[gazza82]

Hi Gazza82, it's negative earth. 
12v going to + on the coil and the - on the coil goes to the Dizzy

Sounds right.

Is there anything in the Dizzy I could have damaged?

What kind of dizzy?

Checked all the connections that were moved/disturbed?

[68+86auto]

 

Hi Ethel,

it's 12v to the coil so I don't think it is ballasted.

 

 1 thing I have noticed is that when the ignition is on, the the distributor cap removed I do not got any sparking when opening and closing the points which I would expect?

I do get a spark if I short the points out with my screwdriver so I'm now thinking points?

Could I have damaged to points somehow

 

 

If that's what it's doing then yes your problem is the points.

[1293gt]

So, after reading up a little my next focus will be on the condensor.

My car has an external condensor (located near the coil). Question is it it possible to test it with a multi meter and I think it should be connected to the - (negative) Coil terminal?

Edited by 1293gt, 17 September 2024 - 07:24 AM.

[sonscar]

The condenser near the coil could have been a radio suppresor.Is there one next to the points as well?Steve..

[1293gt]

The condenser near the coil could have been a radio suppresor.Is there one next to the points as well?Steve..

Hi Steve, it seems there is one in the Dizzy also.

Edited by 1293gt, 17 September 2024 - 12:40 PM.

[viz139]

It sounds like you have burnt out the points . Either the rev counter is faulty and drawing too much current or the condenser in the dizzy was already faulty. Was the car in regular use before this? Replace points and condenser to get engine running again than go back to sorting the rev counter.

[Ethel]

You get a spark (from a spark plug) when the points open. That breaks the circuit in the coil's primary winding which causes its magnetic field to collapse. That generates high voltage in the secondary winding, that can jump the sparkplug gap - with a spark.

 

You can test that bit by disconnecting the black/white wire to the distributor and earthing it on the engine. You'd get a plug to spark when you lift the wire off "breaking the contact" - provided the ignition is supplying leccy to the +ve terminal on the coil and the rotor arm is aligned with the plug you're looking at. You can get round the last bit by attaching the plug lead directly to the coil.

 

If that gets you a spark, but the distributor doesn't, then the distributor isn't "breaking contact". That could be because the points aren't making contact in order to be able to break it or there's a short that earths the coil whether or not the points open.

 

That could be the wiring touching the dizzy body before the points or a failed condenser leaking to earth.

 

The condenser is a capacitor that stores charge (like a very rapid discharging battery) close to the points. That charge jumps the points gap the moment they come close enough, reducing the amount of time the points can arc & burn. It also makes the coil's primary field collapse more rapidly giving a brighter spark at the spark plug.

 

The simplest test for the condenser is to replace it with a known good one - it's always handy to have ignition spares anyway.