This car gets warm and it won't start again. Then when it cools off again it starts again. It has a optima battery, a msd 7al box, a small selanoid?, and a high torque mini-starter. The car will turn over it just won't start. This is enough to drive me crazy.

So it cranks ok? The next time this happens, check for spark and fuel. Im thinking you may have a fuel problem but I would check for good spark when it happens again. Be carefull you dont burn yourself on the engine when getting the plug wire off to check the spark.

What do you mean by a small solenoid?

it has a small silver solenoid on the firewall that the "main" power wire runs to before it goes to the coil or starter. Could being low on charge cause this? I think it could have been fuel, but it was getting plenty it may have even flooded. Plus the starter wouldn't disengage once. I'm going to try to post a picture of the engine compartment. the solenoid is at the top left corner of the picture.

Plowboy72,

My 67 use to do the same thing, I found out that too much heat was causing the gas to boil dry in the carb! I put a phenolic spacer on, and the problem was gone!!!

Brett

Could be vapor lock from too much heat on the carb. Also check your voltage if your running a HEI distributor, they must have 12+ volts at cranking or they dont like to work.

thanks guys, i haven't thought about boiling the gas. It has a nitrous spacer "plate" under the carb. Plus I'm running a msd crank trigger. When I got it the purple and green wires going from the trigger to the ign. was reversed. The purple to the green and the green to the purple. We have since turned this around. It will crank either way. Could this be the culprit?

I would also check for good electrical connections at the starter, and a good electrical ground as well. I had similar hot start issues until I replaced my starter cable from the positive battery terminal - not it starts fine when hot. When the wires get hot, the resistance increases enough that it's a problem for you.

Im guessing battery cables.

One more thought...
Boiling fuel was mentioned, but what about a stuck or sticking float?
What carb are you running?
It's possible that you have a high float level, (dirty needle/seat, sunk float, mis-adjusted float) and it's dribbling fuel after the engine is shut off, thus flooding??
Next time after it is good and warmed up, look down the carb as soon as you shut it off, and see if there is any fuel dribbling.

I'm running a dom. 1150cfm. We found out that the cable was loose on the starter. Ya'll think this is the answer?

Almost certainly.

Don't know if this applys to an MSD system or not. On the older cars, if the coil got too hot it wouldn't allow spark to the distributor. Make sure the coil is not touching the top of the intake. Heat travels up after the engine is shut off. When I experienced this I made sure there was a 1/4 inch gap between the intake and the coil. If the gas is boiling in the carb, one sure FIRE method of verifying it is to have a small bottle of gas to shoot in the carb when this occurs.

Or in a wort case scenario, the bores and piston rings are worn out. I had a similar problem with a car once, and finally found that it lost almost all compression when it was warm. It would fire up right away when cold, but I guess everything expanded when it got hot. I hope this is not the case though.

If it's cranking over ok then it's probably not the cable(s).

Good point on the car turning over - missed that in your original post.

I would bet on vapor lock. An open EGR hole in your intake gasket will heat up your manifold to the point that it would do this - even if you don't use an EGR. There are gaskets that cut off that hole to the intake to avoid this issue. As stated before, a Phenolic spacer under the carb would also solve it.

there is a good bit of vapor coming from the vacum canister, Is that normal? Where would I get a Phenolic spacer?

I'll second (or third) the hot coil problem. They can fail when hot and then start working normal when it cools. I can't remember if it's due to thermal expantion or resistive properties of the windings.

For you other question. The Phenolic carb spacers are here...
http://store.summitracing.com/default.asp?Ntt=phenolic+spacer&Ntk=KeywordSearch&DDS=1&searchinresults=false&N=0&target=egnsearch.asp

okay, It already has the Phenolic spacer. So the coil is atleast 6" away from anything on the engine. Ya'll still think its the coil?

We found out this weekend that my battery is taking a big ole' dump on me. Thanks to everyone who helped me with this problem.

Where is your MSD mounted?

inside, passenger side kickpanel.