69 vert hot not start
Thread Starter
Burning Brakes
Joined: Sep 2010
Posts: 799
Likes: 26
From: Lexington Park Maryland
69 vert hot not start
This is the first time I've worked on a 69, it was drop off to me to get it running. It is running now, however when it warms up after 15 minutes of running. It will die and will not start again until it cools off.
When my 72 LT1 had this problem, I discovered the resistor to the positive side of the coil was removed by previous owner. Its fix now, the 69 I do not see a resistor on the coil, I do see what looks like a condenser. Is that similar to the resistor?
I noticed the wire to it broken: does have anything to do with no start while the engine is hot.
When my 72 LT1 had this problem, I discovered the resistor to the positive side of the coil was removed by previous owner. Its fix now, the 69 I do not see a resistor on the coil, I do see what looks like a condenser. Is that similar to the resistor?
I noticed the wire to it broken: does have anything to do with no start while the engine is hot.
Le Mans Master
Joined: May 2000
Posts: 5,159
Likes: 1
From: Indiana
That sounds like vapor lock. My '69 has always had a problem with that. I lived close to the drag strip so I'd drive it there. By the time I got through tech, it'd be good and hot and run like crap. I re-did the fuel line with Russell's braided but that didn't fix it entirely. Maybe a premium fuel with higher alcohol content would help you.
As far as the condenser, it is inside the distributor under the rotor. If you see a condenser on the outside of the distributor, it may be a noise filter to help with static in the radio. An HEI swap is cheap and easy if you just want to make it a reliable driver.
As far as the condenser, it is inside the distributor under the rotor. If you see a condenser on the outside of the distributor, it may be a noise filter to help with static in the radio. An HEI swap is cheap and easy if you just want to make it a reliable driver.
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
you mentioned a broken wire at coil, on the 69 2 wires go to the coil.
1 wire is the normal run wire, which is special resistance wire.
2 wire is start bypass wire coming from starter, supplying full 12 volts to coil when starting only.
There is no external resister ever, on the 69 unless someone cut off the special resistance wire.
4. after car is warmed up and will not start, look in carburetor,
does it supply gas as you pull on accelerator cable, yes or no ?
1 wire is the normal run wire, which is special resistance wire.
2 wire is start bypass wire coming from starter, supplying full 12 volts to coil when starting only.
There is no external resister ever, on the 69 unless someone cut off the special resistance wire.
4. after car is warmed up and will not start, look in carburetor,
does it supply gas as you pull on accelerator cable, yes or no ?
Team Owner
Joined: Sep 2006
Posts: 31,271
Likes: 4,362
From: Westminster Maryland
Hi,
In 69 wasn't the purpose of the fuel return line from the fuel filter to the tank to return fuel to the tank to help in preventing heating of the fuel and the resultant vapor lock?
Regards,
Alan
In 69 wasn't the purpose of the fuel return line from the fuel filter to the tank to return fuel to the tank to help in preventing heating of the fuel and the resultant vapor lock?
Regards,
Alan
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
Yes the return line allows hot fuel to return,
however if the isolator gasket is not present, the fuel can boil off inside the carb.
the original poster needs to determine if the start problem is related to which problem.
1. due to slow cranking ? ... engine turn over slower after sitting
2. or lack of fuel in carb? ... does fuel exit carb. after sitting ?
3. or poor ignition ?
however if the isolator gasket is not present, the fuel can boil off inside the carb.
the original poster needs to determine if the start problem is related to which problem.
1. due to slow cranking ? ... engine turn over slower after sitting
2. or lack of fuel in carb? ... does fuel exit carb. after sitting ?
3. or poor ignition ?
