Hey guys I am new to this forum but I have a quick question. I have a '66 and I am having a difficult time starting the car after it's been running awhile or it heats up. I'm wondering if it's a choke problem on the carb? I'm confused as hell because it also has a hard time cranking when it's hot as well. Any ideas what's going on and how I fix the choke if that is what it is? Thanks.
When you say it has a hard time cranking when it's hot - do you mean the starter is turning the engine over slow (in which case you may have a heat-soaked starter - a common Pontiac w/headers issue) or does it crank at normal speed but not fire?
You can always disconnect the choke temporarily to see if it helps the problem.
When you say it has a hard time cranking when it's hot - do you mean the starter is turning the engine over slow (in which case you may have a heat-soaked starter - a common Pontiac w/headers issue) or does it crank at normal speed but not fire?
You can always disconnect the choke temporarily to see if it helps the problem.
I guess I could disconnect the choke but I have no idea how....I have no experience with carbs. Someone else asked if it was the original carburator: It's not the original Carter AFB - it's an Edelbrock.
It seems to me though that it is most likely not the carb, it's just a "hot start" problem. I have had this problem ever since I've owned the car. It cranks normally when cold, but once it's hot, it hardly cranks at all. So what's my next step to solving the problem? Do I need to replace the starter or would something like the "hot shot" part from Painless wiring help boost the amperage to the solenoid (painless #30202)? I also found a Hot Start/Bump Start Solenoid Kit from Taylor (Taylor #383480). Would any of these help?
I guess I could disconnect the choke but I have no idea how....I have no experience with carbs. Someone else asked if it was the original carburator: It's not the original Carter AFB - it's an Edelbrock.
It seems to me though that it is most likely not the carb, it's just a "hot start" problem. I have had this problem ever since I've owned the car. It cranks normally when cold, but once it's hot, it hardly cranks at all. So what's my next step to solving the problem? Do I need to replace the starter or would something like the "hot shot" part from Painless wiring help boost the amperage to the solenoid (painless #30202)? I also found a Hot Start/Bump Start Solenoid Kit from Taylor (Taylor #383480). Would any of these help?
It is either a timing issue, crappy battery or a weak starter. Big block Ponchos need a high torque starter because the engine will heat soak after it is shut off. Make sure your battery is good and at least 800 CCA as well.
Also, older cars may have corrosion inside the battery cables that you cannot see. It creeps up the insulator and knocks about 1/2 of your cranking amps out.
Food for thought......
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It is either a timing issue, crappy battery or a weak starter. Big block Ponchos need a high torque starter because the engine will heat soak after it is shut off. Make sure your battery is good and at least 800 CCA as well.
Also, older cars may have corrosion inside the battery cables that you cannot see. It creeps up the insulator and knocks about 1/2 of your cranking amps out.
Food for thought......
Ok so I have a new battery and I just replaced all the new battery cables today, but it still has a hot start problem. My guess is that the timing may be a small issue to the problem, but my guess is it needs a new high torque starter. Any recommendations on what kind to get and where I could get one quick and cheap! Thanks!
sounds almost like vapor lock. I'm sure someone else will chime in though
If your 66 is running the standard compression ratio of 10.75:1 a high torque starter is not needed, I believe your problem is a flooded engine or as Jeremy mentioned, "Vapor Lock",
I found this on Wikipedia;
Quote:
Vapor lock is a problem that mostly affects gasoline-fueled internal combustion engines. It occurs when the liquid fuel changes state from liquid to vapor while still in the fuel delivery system. This disrupts the operation of the fuel pump, causing loss of feed pressure to the carburetor or fuel injection system, resulting in transient loss of power or complete stalling. Restarting the engine from this state may be difficult. The fuel can vaporize due to being heated by the engine, by the local climate or due to a lower boiling point at high altitude. In regions where higher volatility fuels are used during the winter to improve the starting of the engine, the use of "winter" fuels during the summer can cause vapor lock to occur more readily.
Causes and Incidence
Vapor lock was far more common in older petrol fuel systems incorporating a low-pressure mechanical fuel pump driven by the engine, located in the engine compartment and feeding a carburetor. Such pumps were typically located higher than the fuel tank, were directly heated by the engine and fed fuel directly to the float tank inside the carburetor. Fuel was drawn under negative pressure from the feed line, increasing the risk of a vapor lock developing between the tank and pump. A vapor lock being drawn into the fuel pump could disrupt the fuel pressure long enough for the float chamber in the carburetor to partially or completely drain, causing fuel starvation in the engine. Even temporary disruption of fuel supply into the float chamber is not ideal; most carburetors are designed to run at a fixed level of petrol in the float chamber and reducing the level will reduce the air:fuel mixture delivered.
Carburetor units may not effectively deal with fuel vapor being delivered to the float chamber. Most designs incorporate a pressure balance duct linking the top of the float chamber with either the intake to the carburetor or the outside air. Even if the pump can handle vapor locks effectively, fuel vapor entering the float chamber has to be vented. If this is done via the intake system, the mixture is, in-effect, enriched, creating a mixture control and pollution issue. If it is done by venting to the outside, the result is direct hydrocarbon pollution and an effective loss of fuel efficiency and possibly a petrol odor problem. For this reason, some fuel delivery systems allow fuel vapor to be returned to the fuel tank to be condensed back to the liquid phase. This is usually implemented by removing fuel vapor from the fuel line near the engine rather than from the float chamber. Such a system may also divert excess fuel pressure from the pump back to the tank.
Most modern engines are equipped with fuel injection, and have a high pressure electric fuel pump in the fuel tank. Moving the fuel pump to the interior of the tank helps prevent vapor lock, since the entire fuel delivery system is under high pressure and the fuel pump runs cooler than if it is located in the engine compartment. This is the primary reason that vapor lock is rare in modern fuel systems. For the same reason, some carbureted engines are retrofitted with an electric fuel pump near the fuel tank.
Other solutions to vapor lock are rerouting of the fuel lines away from heat generating components, installation of a fuel cooler or cool can, shielding of heat generating components near fuel lines, and insulation of fuel lines.
A vapor lock is more likely to develop when the vehicle is in traffic because the under-hood temperature tends to rise. A vapor lock can also develop when the engine is stopped while hot and the vehicle is parked for a short period. The fuel in the line near the engine does not move and can thus heat up sufficiently to form a vapor lock. The problem is more likely in hot weather or high altitude in either case.
It sounds to me like your starter is becoming heat soaked and needs to be replaced. You don't [i]need[i] a high-torques starter, a replacement will do, but I am happy that I put a high-torque starter on my '70. Starters would only last a couple years and it seemed like I was alway replacing them. I replaced it with a high-torque starter from Ames Performance Products and have no problems since - but not cheap, listing at $209. I believe the high-torque starter's smaller size helps it get more cooling air and it is not as close to the headers as the original starter.
As a qualifiers:
1. I must admit that since the car is not a daily driver anymore the starter doesn't get anywhere near the exercise that it has in past years.
2. I also have a '66 with an ancient stock starter, 12 to 1 pistons, and headers which spins the engine way faster than the high-torque starter and have never had a heat-soak problem with it.
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