Electric choke hot start problem?
 

Hi all,
I recently went to an Edelbrock 600cfm carb with an electric choke. The vette starts great almost all of the time, except when hot- after a good bit of driving if I stop for 10-15 minutes, the engine will crank but won't turn over. I think it's heat related- if I pop the hood and let it cool I get get it started a few minutes later.

Any suggestions on how to remedy?

Thanks!
Greg

Where did you connect the choke wires?

This kind of sounds like the dreaded starter heat soak problem.

You can dial back on the choke and see if it helps any. The choke hot wire should be connected to a point that has power any time the ignition is on.

I had a mechanic install it, so I'm not sure. What are your thoughts?

You may indeed have the starter heat soak problem with the advent of summer temperature conditions. I have been through that frustrating experience. The installation of the Edelbrock may not even be relevant to what you are experiencing. But here is where I am coming from.

I put that carb on my 1967 just two weeks ago. The instructions made it very clear that the choke needed constant 12V, switched ignition power to keep it open after warm-up. I consulted here on the Forum and was given several options as to the power source. I decided on the ignition side of the ballast resistor. The other side of the ballast resistor (coil) delivers only 8-9V to the points and condensor and apparently would leave the choke partially closed at times. Result is mild flooding.

Having said that, and knowing the 1977 is HEI (i.e. no ballast resistor), your mechanic will have chosen another source of power. But 12V or not it is baffling that the car apparently runs well before shut-down: no over-rich characteristics. At least none that you have mentioned. So my inclination is to go with starter heat soak. But I would check that choke connection just as a precautionary measure.

BTW, my solution to heat soak was a GM high-torque mini-starter with Moroso shield.

http://temp.corvetteforum.net/c3/pau...arbfinal02.jpg

http://temp.corvetteforum.net/c3/pau...tarter_003.jpg

Hi Paul,

Hopefully not heat soak- I went thru that last summer and replaced the starter with a PowerMaster high torque mini starter and never again had the problem.

It feels like a choke problem- I have to pump the gas and keep it cranked, then it will turn over real weak. But then it runs perfectly.

Yeah it's strange. Starts great when cold at any time of the day. But if I try and start it 15 minutes after driving she will crank but take a while to turn over.

Could the wires going to the carb choke be getting too hot to carry sufficent current?

The choke should be wide open under the conditions you described. I cannot figure out why you need to pump the gas. When was the last time you checked timing?

BTW the choke wires should not be hot.

Another BTW, the choke is grounded? I am going out now to clean up my car for a show tomorrow but will get back to you if need be. The choke should be grounded to its own housing. I will take a pic.

Here is a pic of the ground (black) wire.

http://temp.corvetteforum.net/c3/paul79//ground04.jpg

The condition of the choke wouldn't affect how it cranks, only how well it starts. Besides the previously mentioned heat soak problems, heat can also cause slow cranking in other ways. As the cables and connections heat up they can't flow as much current, resulting in less power to the starter. This often becomes evident if there is a less than good connection anywhere in the circuit or the cables need replacing.

That was my thought as well. It's not the choke. Hence the comment on timing. But cable corrosion is another factor as you have noted. It's a step-by-step exercise at times. But once resolved it can be put away for several years. I went through a lengthy process of SS bolts, new electric cable/lines, and di-electric grease on most connections before I rode with confidence on my 1979. But once the process is done, have fun!

Dangnabit, guess I'll try running new wires to the starter. When I was heat soaked with the old starter it wouldn't even crank or click or nuthin till I let it cool and tapped the silenoid with a golf club...

Thanks for the help guys!!