Technical Runs great cold - Stops when hot

[Texas500]

I've been fighting this problem for several weeks now. Initial problem was cold start/running is great. Died after 10-15 minutes. Will not start. If I wait for 15-20 min, starts right up. Will last another 10 minutes. Repeat.

Did the following:
-Resurfaced Carb
-Replace carb spacer & gaskets
-Replace fuel pump
-Replaced points with Pertronix Ignitor (hall effect)
-Replaced coil, cap, and rotor
-Replaced spark plugs - old ones were fouled black
-Replaced mech voltage regulator

After the regulator replacement, the car will continue to drive but has a terrible miss at all speeds. Before the new regulator, the car would miss then die a short time later. The last time out, I drove the car 20 km.

I noticed when I turn on the headlights, the miss gets A LOT worse and the car loses speed. Turn headlights off and there's a noticeable improvement. Miss is still present but not was bad. Could this be a battery or dynamo problem? Aside from the spark plug wires, they are the only things I haven't replaced!

 

[dunnah01]

Heard of problems with venting of fuel tank causing supply starvation

 

[stevehg]

It looks like you have a few problems at once. I'd start by fixing battery/dynamo issue first.

 

[GeorgeDamper]

I've been fighting this problem for several weeks now. Initial problem was cold start/running is great. Died after 10-15 minutes. Will not start. If I wait for 15-20 min, starts right up. Will last another 10 minutes. Repeat.

Did the following:
-Resurfaced Carb
-Replace carb spacer & gaskets
-Replace fuel pump
-Replaced points with Pertronix Ignitor (hall effect)
-Replaced coil, cap, and rotor
-Replaced spark plugs - old ones were fouled black
-Replaced mech voltage regulator

After the regulator replacement, the car will continue to drive but has a terrible miss at all speeds. Before the new regulator, the car would miss then die a short time later. The last time out, I drove the car 20 km.

I noticed when I turn on the headlights, the miss gets A LOT worse and the car loses speed. Turn headlights off and there's a noticeable improvement. Miss is still present but not was bad. Could this be a battery or dynamo problem? Aside from the spark plug wires, they are the only things I haven't replaced!

Sounds like a poor earth - body to engine

 

[Paolo66]

I'd check voltage at battery. Start it up and check voltage again. Switch on headlights and check again. If it really drops when you switch on lights you've got a bad earth
Damian

 

[Texas500]

Heard of problems with venting of fuel tank causing supply starvation

Yea, I tried running with the fuel tank cap removed.

It looks like you have a few problems at once. I'd start by fixing battery/dynamo issue first.

Hind sight is 20/20

I'd check voltage at battery. Start it up and check voltage again. Switch on headlights and check again. If it really drops when you switch on lights you've got a bad earth
Damian

Thx. I'll give it a try.

 

[lordsnowy]

if the earth check does not solve the issue...

it could be the wire going to the coil is faulty...when you rev high the voltage going to the coil increases to 14v (or should) the wire may be arching someone along the wire...

i am also assuming you replaced the wire going from the coil to the distributor...these breakdown internally due to heat and age...should be replaced when replacing points....

I did have a car with a similar problem (not 500) where they fitted a switch to immobilise the car for security...the switch was a low amp unit and reduced the current at high speeds to the coil. check the lights are not connected to the wire going to the coil....inlikely but just in case