Stop go stop go

[Michael Mckiernan]

Hi all , just had a strange breakdown !

Not driven my TR6 for about 7 weeks due to a new hip and the rotten weather,

so lovely day Tuesday set of for a spin and a coffee , but fuel first .

Petrol station 1.5 miles away almost didn't make it but thought i might be lower on fuel than i thought.

Filled up with £40 of esso 99 octane as usual but the car would not start. 

Anyway pushed it off the pumps gave it 10 mins and it fired up but would not run cleanly , seemed as if the choke on the metering unit was stuck on ,

but it wasn't .  Long story short checked injectors , plugs , and connections but to no avail so gave up and called the RAC.

Mechanic turns up we start engine as its cold leave it to warm up and it cuts out as soon as you try to drive away.

So he pulls off the distributor cap and we put the coil lead to the center of the rotor arm and it goes to earth , not ideal !!!

Buy a rotor arm from local factor and its a black one with a rivet and that's even worse.

By this time it's stone cold and we get it going and make it home 4 hrs later.

Contacted Martin ( distributor doctor ) and he sent me out a new rotor arm and cap , just fitted and done 10 miles running lovely again.

never would have thought that a faulty rotor arm would give you those sort or symptoms  , but when you think about it the drop in spark was ok to burn the fuel when cold

but fowled the plugs when hot.

Every day's a school day .

All the best Mick

[astontr6]

I had similar problems 20 years ago before the problem was identified as the rivet. My rotor arm was bought from Halfords. Then by accident when I was coming back from Westlands I called in at the DD and he put me straight and I bought 2 Red Rotor arms. I am still using one of them but gave the other one away when on another TR trip a TR in front of me had his engine cut out with the same problem. As far as I am concerned bin those rotor arms with the brass rivet.

Bruce.

[michaelfinnis]

6 hours ago, Michael Mckiernan said:

Hi all , just had a strange breakdown !

Not driven my TR6 for about 7 weeks due to a new hip and the rotten weather,

so lovely day Tuesday set of for a spin and a coffee , but fuel first .

Petrol station 1.5 miles away almost didn't make it but thought i might be lower on fuel than i thought.

Filled up with £40 of esso 99 octane as usual but the car would not start. 

Anyway pushed it off the pumps gave it 10 mins and it fired up but would not run cleanly , seemed as if the choke on the metering unit was stuck on ,

but it wasn't .  Long story short checked injectors , plugs , and connections but to no avail so gave up and called the RAC.

Mechanic turns up we start engine as its cold leave it to warm up and it cuts out as soon as you try to drive away.

So he pulls off the distributor cap and we put the coil lead to the center of the rotor arm and it goes to earth , not ideal !!!

Buy a rotor arm from local factor and its a black one with a rivet and that's even worse.

By this time it's stone cold and we get it going and make it home 4 hrs later.

Contacted Martin ( distributor doctor ) and he sent me out a new rotor arm and cap , just fitted and done 10 miles running lovely again.

never would have thought that a faulty rotor arm would give you those sort or symptoms  , but when you think about it the drop in spark was ok to burn the fuel when cold

but fowled the plugs when hot.

Every day's a school day .

All the best Mick

Curious as to the root cause of this problem. I don’t see how a weak spark would burn fuel ok when cold but foul the plugs when hot, I would have thought a better spark was required when cold. Any experts able to explain?

Mike

 

[Tim D.]

9 hours ago, michaelfinnis said:

Curious as to the root cause of this problem. I don’t see how a weak spark would burn fuel ok when cold but foul the plugs when hot, I would have thought a better spark was required when cold. Any experts able to explain?

Mike

 

It think it is more that the rotor arm insulation breaks down when hot. 

[Michael Mckiernan]

1 hour ago, Tim D. said:

It think it is more that the rotor arm insulation breaks down when hot. 

I thought that as well, so to be check when i got back yesterday from the run

i switched back to to original rotor ( which was stone cold ) and the problem was there straight away .

Just to add it was a red rotor arm fitted and reasonably new, but not a D.D one .

Mick.

 

 

 

[RobH]

13 minutes ago, Michael Mckiernan said:

i switched back to to original rotor ( which was stone cold ) and the problem was there straight away .

The nature of an electrical breakdown is to become worse with time.  Surface contamination or some flaw in the material allows current to flow which produces a carbon track. The longer the current flows the more carbon builds up and hence the resistance gets lower which allows a higher current to flow..... and so on.  Usually that happens quickly and is irreversible but it is possible that some temperature-related effect could come into play initially, prior to complete failure. 

[stuart]

3 hours ago, Michael Mckiernan said:

Just to add it was a red rotor arm fitted and reasonably new, but not a D.D one .

Mick.

 

 

 

Theres a lot of rip off red rotor arms around that are just as bed as the riveted type, genuine ones have "DD" On them.

Stuart.

[Michael Mckiernan]

Hi Stuart , the red rotor was fitted along with a set of plugs and a dizzy cap just before i bought it 3 years ago ,

so for a " rubbish " product i should count myself lucky.

The Distributor Doc's have as you say DD And made in England on them also got a new cap as not sure of the quality 

of the old one.

The DD cap has lovely brass contacts as apposed to the aluminum type that was fitted.

Cheers Mick.