General Still not working (hot running)

[hodgy18]

Good evening all

From my last post and reading others I have carried out the following to try and eliminate the car cutting out when warm and not starting when hot:

Fitted a brass t-bar from the return pipe from the carburettor just before the fuel pump to to get rid of possible fuel vapour

And

Adjust the valve clearances as they were very tight.

The both giving as possible solutions to help the car when hot.

Today after the fixes it unfortunately did pretty much the same. Coughed and spluttered when I parked up and cut out.

Anyone got any further thoughts on curing this annoying issue? It really is making the car unusable.

My car is a 71L with a 650 engine fitted.

Any further recommendations are most welcome on helping this issue.

Regards

Chris

 

[AndrewHarvey]

Have you removed fuel line and tried turning the engine over ti see the volume of fuel the tank & pump are delivering when this incident it happening?
Vapour lock, poor pumping ,blocked fuel line.....these are all likely issues

 

[hodgy18]

Hi andrew. The fuel line seems fine when the car is revved. The issue came about after I bought the car and discovered the return line on carburettor was uncapped. So i capped it off. I thought this was issue so fitted the t-piece to eliminate fuel vapour. This didn't work so adjusted valve clearances. It did start alot better but issue remains.

 

[AndrewHarvey]

These engines run hotter than the average motor.
If heat soak is an issue.....does your carburetor got hot?
They run a spacer to prevent the carb getting hot and then having problems.
Condenser and coil also get hot and malfunction

 

[Pazzo500]

These engines run hotter than the average motor.
If heat soak is an issue.....does your carburetor got hot?
They run a spacer to prevent the carb getting hot and then having problems.
Condenser and coil also get hot and malfunction

I second AndrewHarvey's suggestions. I know you said the problem only started after you capped the carb return outlet, but the next time the car is hot and dies you should double-check that you do have a spark so you can eliminate a heat damaged coil/condenser as an issue.

 

[Yellblob]

Hi,
Im not talking as an expert here... but this problem is so common yet can be caused by just about anything. An organised approach to ensure satisfactory functioning of each sub system should find it. I thought I had a fuel issue ( I did at one point) but my friend used a CO meter and found I'd set it far too rich and also I had loose ignition cables and worn dynamo brushes! The car is running better now but all the shaking that goes on is bound to cause another problem.....

 

[1500500]

I second AndrewHarvey's suggestions. I know you said the problem only started after you capped the carb return outlet, but the next time the car is hot and dies you should double-check that you do have a spark so you can eliminate a heat damaged coil/condenser as an issue.

My most common hot running breakdowns were caused by condenser failure.

 

[jackwhoo]

My most common hot running breakdowns were caused by condenser failure.

Feel the ignition coil temperature next time, it shouldn't be too hot to touch, if it is too hot you have a faulty coil.
This does happen don't think it's a long shot.

Check for a good spark next time it stops too as previously suggested by another member.
Carry a spare spark plug with you so you don't have to handle very hot spark plug.
Check air filter not blocked.

 

[gordinir8]

Feel the ignition coil temperature next time, it shouldn't be too hot to touch, if it is too hot you have a faulty coil.

My car runs pretty good... with its little problems but acceptable. My coil is impossible to touch:devil: It is extremely hot but i always thought that's because it is close to the exhaust and all the hot air coming out of the engine hit's direct the ignition coil. Am i missing something here? Are your coils running not hot but acceptable to touch?

 

[jackwhoo]

Ok I was given experience of coils on other classic cars where coils not next to exhaust.
Try a new coil anyway , they are cheap make sure you get a coil the same voltage as your battery.

 

[jackwhoo]

Shouldn't the cooling fan be blowing that hot air away from the engine?

 

[Pazzo500]

Shouldn't the cooling fan be blowing that hot air away from the engine?

The fan sucks in cool air and blows it from left to right across the engine, so the hot air blows out towards the coil. There should also be an exhaust heat shield that extends out from the base of the coil towards the distributor that helps shield the coil from muffler heat.

But again this is only relevant if the spark is the culprit in the hot-starting problem.

 

[jackwhoo]

Re Reading this thread from the beginning .
You said the problems only started when you blocked the uncapped return pipe on the carb'

I think the pipe you capped isn't a fuel return to tank .
Put everything back as it was before you had problem and see if problem gone.
I have feeling that pipe you blocked may be the float bowl breather which must be open to atmosphere.
Good luck and please post results.

 

[hodgy18]

Hi all. I fitted a non return valve to make sure the fuel was continuos.

Anyhow - checked when I returned from a quick run and the coil was hot. Tried for a spark ...and non present when hot. I followed the car whilst my dad drove and it smelled very rich.

Onto the next purchase for the elimination process of hot running issue.

 

[jackwhoo]

Hi all. I fitted a non return valve to make sure the fuel was continuos.

Anyhow - checked when I returned from a quick run and the coil was hot. Tried for a spark ...and non present when hot. I followed the car whilst my dad drove and it smelled very rich.

Onto the next purchase for the elimination process of hot running issue.

The fuel pump contains two non-return valves.

 

[hodgy18]

Evening all

I think I found the cure to my issue in the form of a Lucas dlb105 coil!!!

It's drove fine when hot and starts back up no problem when hot......I'm happy again ?. Just in time for tomorrow's show corbridge.

I gave "name tbc" a polish and a rare treat in the form of a new set of mats!

Have a hopefully sunny weekend everyone.

 

[jackwhoo]

Evening all

I think I found the cure to my issue in the form of a Lucas dlb105 coil!!!

It's drove fine when hot and starts back up no problem when hot......I'm happy again ?. Just in time for tomorrow's show corbridge.

I gave "name tbc" a polish and a rare treat in the form of a new set of mats!

Have a hopefully sunny weekend everyone.

Very pleased you have cured your hot running issue. There are some very helpful people on the forum.
I think andrewharvey was first to suggest ignition coil as potential cause.

Thank you for posting confirmation of the cause of problem.

 

[hodgy18]

I think it was, so many thanks andrewharvey. I think after tomorrow, I may remove the t-piece and cap off the carburettor as previously set up. My dad pointed that maybe as others hadnt solved the issue through this, then reverse it all back,as there's an awful lot of hose clips going on - increasing the risk of fire etc.

 

[hodgy18]

Went to Corbridge today and it ran well. Came back home and it took a while to get out of car park, ran well all the way back until the last turn. Came to a near spluttering halt. After 2mins it started up. Think it was the coil getting too hot. It ran alot longer and restarted alt quicker. Looks like devising a cooling tube to the coil.

 

[gordinir8]

As I said in previous page coil gets hot because hot air hits it when exits the thermostat housing. I am thinking my self to enclose it to a bigger tube housing and take some cold bleed air from the engine housing before the cylinders and divert it to the new coil sleeve. I think that way it will be cool all day. Just a thought and a mod for fun.Those days in Greece temp can't go bellow 42, I don't even dare to crank it. Of course even if the car can make it I can't get in there and fry.