Engine cut- out problem

[Ernest]

Hi all

Out in the 6 today - 10 miles into run all going well then the engine cut out.

RAC came out checked petrol supply (which was OK) and the 'fiddled' with connections related to distributor and coil.

Car then started (it had been siting for about an hour) and so set off again. About a mile up the road

the engine cut-out again.

RAC came out again and the new mechanic suggested a new coil required - he went and bought one and fitted it to the car.

Now the car had been siting for about 2 hours. It started easily and so all seemed well.

But about 5 miles on the engine cut out yet again.

I was within walking distance of home so just parked it up and walked home.

I did notice that the new coil was very warm (almost hot) - is this normal?

Ay ideas on possible cause of cut-out would be much appreciated.

Although the coil was very warm I can't see that its position would be a problem as the car had been running well for the past three years.

Any suggestions?

Best Wishes

Ernest

[RobH]

3 minutes ago, Ernest said:

I did notice that the new coil was very warm (almost hot) - is this normal?

Yes.

Do you have points ignition or electronic?  Is the petrol tank breather hole clear ?

[Ernest]

Hi RobH

Thanks for response.

The car has Lumination ignition, so would be electronic I think. Although one of the RAC guys did suggest

I change the roter arm?

But he was only supervising the trannie and neither of them took the distributor cap off.

So perhaps Lumination can still include a points-based ignition.

Sorry to be so ignorant on a quite basic matter.   

I walk up to where the car broke down earlier and it started first time and drove the mile or so home fine.

I do think that heat must be involved.

Best Wishes

Ernest 

[RobH]

Likely but not necessarily heat.  

If the petrol tank breather is blocked then after a while the use of fuel creates a vacuum in the tank which stops the petrol flow.  After some time stopped, enough air can leak into the tank to allow fuel to flow again for a while, until the vacuum re-forms after some miles.  It's easy to check. When the car cuts out, take off the filler cap. If there was a vacuum there will be an audible  rush of air into the tank. 

Electronic ignition can cut out with temperature - I had a Pertronix module that did that.   After about half an hour it cooled down enough to work again until the next time.  (Lumention systems do not use the points - they are either magnetic or optical depending on the type. )  Again fairly easy to check - just look for a spark before things  have had chance to cool down. 

[Ernest]

Hi RobH

The first RAC guy did spray petrol into the PI system and still the engine would not start - He concluded from this that it would not be a petrol problem.

This is a frustrating problem as I can be confident about take the car our out even for a short run until I can resolve the issue.

I am still focusing on the electrical system and heating - but will do the petrol cap test if/when the engine cuts out.

I can't understand why car has been fine for three years but that I now have this problem - I don't know what else to replace.

I wonder whether solenoids differ - the new one is just a generic type bought from a local part shop and perhaps I should replace this with a Luminex one.

Any advice would be valued - I am getting desperate.

Best Wishes

Ernest

[RogerH]

Hi Ernest,

do you have a spare Luminition  module - if so fit  it. see what happens.

I would also re-fir the original coil as clearly it wasn't that (maybe)

 

Roger

[RobH]

The easiest thing to do to eliminate the Lumenition would be to install a standard points system but that depends on whether you still have the required bits.  Some electronic systems replace the standard base-plate.

By 'solenoid' I guess you meant ignition coil.  A generic one should work just fine but it does suppose the chap bought the right resistance type.  What year is your car? Later cars had a 'ballasted' coil system.

Edit:  Roger is right of course - the original coil should be fine to re-fit. 

 

Edited September 30, 2023 by RobH

[Ernest]

Hi Roger and RobH

The car is a 1972 CP - all fairly original. Restoration by Rees Bros. back in the mid 1990s.

I do have the original Luminex solenoid removed yesterday, but bear in mind that this was fitted when the problem first occurred. 

A question I have is.... should the body of the solenoid be very warm, verging on hot, after just a short run?

Thanks both for the suggestions.

Best Wishes

Ernest

[RobH]

Ignition coils will get hot - particularly if mounted on the engine. It's normal.  The fact that the coil was replaced but the fault is still there, suggests this eliminates the coil as a cause. 

But - 

I think a '72 car was pre-ballasted ignition as standard but the Lumenition one is an unknown quantity.   Do you have details, make and type numbers, for both coils?  It is just possible the RAC chap bought the wrong type but of course the car did run for a while after he swapped it.  

[Andy Moltu]

Rotor arm failures are common with the only rivet type. Run for a while and then short out. So definitely change and 8nspect the dizzy cap at the same time looking at the carbon pencil and for tracking.

Does the fuel pump note change when it cuts out? Cavitation or a tank “vacuum” will usually be accompanied by a change in pump note.

Change one thing at a time or you won’t know where the fault was sited and you may well have to bin a number of good, tried and tested spares.

[Ernest]

Hi Andy, RobH, Roger

Thanks all for advice - I am thinking that the solenoid is probably OK and 

I am beginning to think that my next step is to consider the distributor.

I am away for a few days now but will get onto this next week.

Best Wishes

Ernest

[Steve-B]

@Ernest I discovered that the inertia switch in my 1973 had partially melted inside a few months back (after multiple failures/ cut offs just like yours!) so hardwired around it after removal when I discovered it and so far no further issues. I have a new switch ready to install, but in the interim based on great assistance here, I have replaced the coil,new Distributor Doctor red rotor, new fuel relay,  new pre-filter before pump. 
I’ll be curious what you find, as no doubt, others will as well

Edited September 30, 2023 by Steve-B

[Ernest]

Hi Steve

Thanks for this interesting message - Please excuse my ignorance but what is an 'inertia switch'?

Best Wishes

Ernest

[Steve-B]

25 minutes ago, Ernest said:

Hi Steve

Thanks for this interesting message - Please excuse my ignorance but what is an 'inertia switch'?

Best Wishes

Ernest

@Ernest on the passenger side firewall to the left of the batter will be (or should be) a grey cylinder with a small button-like thing on top which has 2 wires leading to it. That's the inertia switch, so unless your car does have one (or previous owner removed it) that's what I'm speaking of. The shaft inside it makes contact with the 2 brass leads in case of a shunt, or should.

In mine the shaft was bent like this:

Edited September 30, 2023 by Steve-B

[Mk2 Chopper]

Ernest, you need to do the following checks when this happens again:

With a spare spark plug remove an ht lead connect to the spare plug and ground it against the engine block and with someone cranking the engine over, see if there is a spark. 

If the above checks out, now remove a plate between two injectors (one bolt) and pull out one of the injectors and again with someone cranking the engine, do you get a nice cone spray from it? 

One of these checks should find the problem and then it's a case of trying to resolve what's causing the fault in either of those systems. 

Gareth

[Peter Cobbold]

Inertia sw failure stops the PI pump, you should be able to hear that. These failures are an accdient waitng to happen. One moment all OK, the next a dead engine....with no warning.

Peter

[Ernest]

Hi Gareth and Peter 

Thanks for the suggestions - the pump is working when ignition as usual.

The RAC guy did the checks you mention Gareth - and it was whilst fiddling with the coil/distributor

that the engine fired up.

When I asked him what one his actions sorted the problem (or seemed to) he said he did not know!

And he thought the crimps holding wires on tope of the solenoid might have been a bit loose. I have since tried to tighten these but 

the problem returned a couple of miles up the road.

I am thinking that I need to turn my attention to the innards of the distributor.

Best Wishes

Ernest

 

[ntc]

14 minutes ago, Ernest said:

Hi Gareth and Peter 

Thanks for the suggestions - the pump is working when ignition as usual.

The RAC guy did the checks you mention Gareth - and it was whilst fiddling with the coil/distributor

that the engine fired up.

When I asked him what one his actions sorted the problem (or seemed to) he said he did not know!

And he thought the crimps holding wires on tope of the solenoid might have been a bit loose. I have since tried to tighten these but 

the problem returned a couple of miles up the road.

I am thinking that I need to turn my attention to the innards of the distributor.

Best Wishes

Ernest

 

Good idea first check the small brown earth wire attached to the base plate of the distributor 

[marko]

You need to go back to basics.

Fuel or Spark issue!!!

Buy one of these off Amazon and put it on top of one of the spark plugs and then put the lead back on.....

Run the car until it stops again and try to start it........if the sparkrite tester shows a spark then the electrics are all good and the spark is reaching the plugs!

If not then work your way back from the plug leads to the distributor - check the Rotor Arm as others have said - If its a Black one, throw it away and get a genuine distributor doctor red one from Martin Jay (Not Ebay as there are chinese copies being sold on there)

It sounds to me like the Rotor Arm or a bad connection on the coil or the 12v wire from the fuse box....

If you've got a good spark at the plugs then try bypassing the grey fuel cut off (inertia switch)

If it's not that - then get someone who knows what they are doing to have a look!!

 

Edited September 30, 2023 by marko

[Peter Cobbold]

The connector to the loom can fail invisibly under the insulating sleeve.

[CharlieBubbles]

To RobHs earlier thoughts on a tank vacuum building up, another one quick and easy one came to mind - has the seal inside the fuel fuller cap been changed? Might just be worth checking it’s the one with a breather hole in rather than the one without.

 

Edited October 1, 2023 by CharlieBubbles

[Z320]

Hi,

last year i helped a guy with his TR4 next to the street.

The pick up coal pin in the center of the distributor cap was worn / short,

with my spare cap / cables / plugs ( ready to fit) he went home.

Ciao, Marco 

[Ernest]

Hi ntc, Marko, Peter, Charlie, and Marco

What lovely set of responses to add to al the others received so far.

The fuel seal rubber has not recently been renewed Charlie and the one the car doe have the hole.

It does seem that I need to start by closely inspecting the distributor cap and then fit a new rotor arm (I think

that the one one in it is a 'red' one). I suspect that I will probably be getting '......someone who knows what they are doing to have a look!!'

As per your final suggestion Marko

Thanks again to all who have responded to my initial posting. It just sows that value of being in the TR Register

Ernest

P.S. During the time spent waiting for the two of RAC rescue vans - First 90 mins  hrs in Westerham village and the later another 90 mins a couple of miles up the road for the second breakdown.

In this time I had a man come out of his house to offer me tea and biscuits, a woman from across the road who came and offered tea. Then I had two different women pull up, one saying they had a set of 'jump leads' if this would help, and the other just offering to help. I also had a van driver pull up who said he had a 'start box' if any good. How nice are most people.......... allowing me to, sort of, quite enjoy the day!

Another guy pulled up to tell me about the three 4a's he used to own - mind you, this was of little help and indeed caused a bit of a traffic build up!  

[Anschutz]

I had trouble with my Luminition module last year and it would misfire badly when it got hot.( it was 30years old!) replaced with points and it was fine.

Fiest poit of call though is the rotor arm.

I am having problems now with the coils, they don't last long and I presume they are all made in China?

Edited October 2, 2023 by Anschutz

[stuart]

8 minutes ago, Anschutz said:

I had trouble with my Luminition module last year and it would misfire badly when it got hot.( it was 30years old!) replaced with points and it was fine.

Fiest poit of call though is the rotor arm.

I am having problems now with the coils, they don't last long and I presume they are all made in China?

Talk to Martin (Distributor Doctor) he does good coils.

Stuart.