won't start when hot

[Ronnny]

My 68 long bed has a 350 with a 400 tranny. It has the points from the first motor it had. The truck starts and runs fine. If you cut the motor off it will start right back up. But if you turn it off long enough to get gas or run into a store it will not restart. It does run good. i was told maybe the coil but have not swapped it out yet to see. I plan on putting in a hei dist. soon. the carb runs fine and i do not think it is the choke but could be wrong. If i cut it off i can start right back up. But if i let it set 5 minutes it needs to go ahead and set a another 10 or so. any other ideas?

[eastcoastcivil]

My 67 used to do the same thing only it wouldn't start back up right away like yours. Turned out the starter was getting too hot because of the headers and the solenoid was becoming heat sinked (the magnet wouldn't work until cooled). I just put a heat shield on the headers and that solved the problem. Not sure if that might be your problem but worth a shot.

[swamp rat]

I agree on the starter getting hot, but you didn't mention if you gad headders or not?

I put a set of Doug Thorley Try Y's on my 350 after i built it and i had the same problem, the starter was getting hot as the lack of airflow when i shut it off was too hot for it. I had to wire up a ford style starter Bendex on my passenger fender wall

[nyncompute]

Just to clarify.. will it crank freely, i.e. drag from the starter when warm, or just crank and crank and not fire up.

[CCCC]

The above posts are good - may identify your problem - but also have had a couple of engines that did something similar because the lack of air circulation when first sitting enabled engine heat to vaporize the fuel at one "hot" spot in the delivery line - so after a short while no fuel flow due to a sort of vapor lock situation. After cooling down, all was OK. So, I bent or moved the line further from the block or put an insulator in between. Just one possibility.

[swamp rat]

Oh, on my engine the solenoide would just click like i had a dead battery but the battery was fine.....

Hum, maybe possible the coil gets to hot without airflow? Hard tellin for sure, if it was me i'd want to check for spark the next time it does it, do you have one of the in line spark checker lights that you plug into the spark plug wire then onto the plug?

Your float bowl should have enough gas in it to fire up the engine butr you could pull the airfilter and rock the linkage and make sure its squirting gas in the carb. My fuel line is steel and is bolted to the front of the block and up along the intake manafold to the carb never had a fuel vaperization problem from that. But like it was posted be sure to check how close the delivery line from the tank to the pump, and from the pump to the carb are from the exhaust. It couldn't hurt to be looking for rotted hoses and replace them while your at it.

[pat 70/71]

I think this is called (heat soak) starter gets hot& drags/ (long crank) I have this problem with my 71, going to order a mini starter for my truck. starts great when cold. drive it twenty minutes and it will start but, takes a long time to start.( heat from the headers) anywho, good luck hope this helps cheers, Pat

[Shyguy]

If your engine turns over fine, but does not fire up it is not a problem with the heat soak of the starter.

You did not mention what carb, you have. If it is a Q-jet or Edelbrock the gas may be boiling out of it if it sets for more than a few minutes.

You could put a phenolic spacer under the carb which should prevent boiling of the gas.

[OKLAHOMAWELDER]

I had this problem with a SBC in a toyota 4x4 I had but it had an MSD ignition on it. It would start and run just fine, then when you killed it after driving it, it would not start until it sat and cooled off for a while. We pulled the MSD off of it and never had another problem with it. So, just a thought, maybe check the ignition system....

[jcis4me]

Aloha
Mine did the exact same thing. The fuel line was too close to the exhaust, so I ran new fuel lines (mine are all rubber), along the out side of the frame well along with the electric fuel pump and viola problem solved!
My 2 cents worth!
Aloha
Marty

[nerve]

My 72 does this sometimes...turns over, but won't fire right away...I gotta pin the gas pedal...and then let her rev for a few or she will stall...I think it's the angle of the fuel lines...If I park slanted forward on hill, forget about it...

[cdowns]

i agree that phenolic spacers prevent fuel peculation in the carb

another common cause is lazyman rubber fuel lines laying on the manifold or resting on the engine block causing a vapor lock condition, they also in the long run cause nice big fires in the engine compartment

[Ronnny]

It is not the starter for it turns the motor over no problem until the battery dies. Will look to see next time i drive it if it looks like getting a vapor lock. It is running a tired old q-jet that runs really well. will swap out the coil before i drive it again since i have a few laying around. It is supose to rain the next few days and the wipers do not work. It is on my list to see ifin it is the switch or the motor for the wipers that is broke. I am not into power a lot and thought about this 2 barrel setup my wife's brother in law gave me. Complete from intake to air cleaner.

[pat 70/71]

Originally Posted by Shyguy

If your engine turns over fine, but does not fire up it is not a problem with the heat soak of the starter.

You did not mention what carb, you have. If it is a Q-jet or Edelbrock the gas may be boiling out of it if it sets for more than a few minutes.

You could put a phenolic spacer under the carb which should prevent boiling of the gas.

I learn something every day (never thought of boiling the fuel) thanks for your response. going to check into a phenolic spacer & make a hard line from the pump to carb (think I could be running a bit lean also) cheers, Pat

[turner72]

I had the same problem with mine. I had some corrosion on the cap and rotor. Cleaned it off, set the dwell and timing. It has started perfect ever since.