mulchie

My 71 LT-1 doesn't want to start when the engine is hot. Any ideas on what might be causing this? Engine is well tuned and running strong. It starts right up when cold.

73Ken73

Buy a mini starter and you will never have that problem again. When your car is hot and wont start , try putting ice on the starter. I have done this before. A large cup of Burger King ice will work.

1LE

If your running headers, there is a lots of heat down by the starter. Two things you can do. Put a heat shield around the starter, and get a remote solenoid. Both of these items you can buy for under $ 50.00 through Summit or Jegs.

Paul L

The problem is called starter heat soak. This was my solution: a GM high-torque mini-starter with heatshield. GM part #12361146. It costs about $180.00. There are aftermarket versions as well at higher and lower prices.

Neo Fender

I think we have an apples and oranges topic here. A hot cranking problem is one thing. A hard starting problem could be something like vapor lock, etc.

Paul L

You could be correct! Heat soak is so prevalent that I simply made an assumption. If the starter cranks then he does indeed have a different problem. Perhaps he will be more specific in reply.

mulchie

It's definately a hard start situation. The engine turns, therefore, I am assuming that the starter is functioning properly??. What about vapor lock?

Jvette73

This only applies to carburated engines:
Not to dis you or anything but it could be caused be starting procedure. First of all, when the engine is cold it usually takes a 4 or 5 good pumps of the pedal to load it up so it starts right away. On a hot restart( that is turn it off and right back on again) an engine should not need any pumps. If its partially cooled down but still warm it might need one full pedal pump to reload a bit more gas for startup. Vapor lock usually manifests itself by the car actually starting right up, but then cutting out after youve drivin 50' or so.

Jay M

Mine has the same problem, I normally don't pump the gas to start it when it is already warm, but when it is really hot outside the engine must turn over for quite a while before it will finally start, and even then it doesen't sound very good at first. Another strange thing. While it's trying to start the windshield wiper door opens up. :confused:

My guess is that it has something to do with very high temps. in the engine compartment.

~Jay

Jvette73

This again, applies only to carburated engines.
A warmed engine will start back up imeadeatly after its been shut off because there is still fuel vapor present in the intake. If it sits for 10 or 20 or 30min....Its still warm so the choke wont operate. However, the fuel vapors have since evaporated from the intake. So after it sits a lenght of time, it may need a pump or two from the right foot to get it goin again.

Excessivly advanced initial timing can also cause had starting on warmed engines.

virtue4u

I have two carbureted engines and love them both, but the procedure to start them is VERY DEPENDENT on the length of time they have not been run. My oldest car is a 72 Ford. When it sits for a week without running, then I pump the hell out of the accelerator while cranking it. It seems like it has to prime itself.

The 77 Vette starts immediately when cold without any pedal if it was run within the previous 2-3 days. If it sits for a week, I need to pump a little bit. I have only had my car for about a year, and I think I am still learning how to start it hot after a 30 minute rest. It always starts, but I wish I could get it to start IMMEDIATELY like it does when cold.

norvalwilhelm

If it is hard starting when hot like pulling in for gas and when you go to restart it and it needs alot of cranking and then starts and runs lousy for a few seconds I would blame this on flooding due to fuel vaporizing or more likely a small leak in the carb allowing raw fuel into the intake manifold. To start a warm engine you should not have to give it any shot of fuel. I step on a throttle lightly not pumping it but just slightly opening the throttles a little and turn the key and it fires right up and quickly idles totally normal. No smoke out the back due to flooding.
Norval