Some background first... This past summer I finished restoring a '66 Coupe with a 302 and C4. I don't have any history on the car prior to my acquisition 1 & 1/2 years ago. I didn't tear into the bottom end as compression was good and consistant among all the cylinders, I did replace the top end with a Weind intake and Edlebrock 650 carb. The engine is still on points and a mechanical fuel pump.

When cold starting it turns right over and starts great, and runs smooth with the exception of some slight hesitation at times from a dead-stop, it doesn't hesitate at all when the choke is still on (i.e. fuel & revs are up) or if I give it a little pedal before I hit it. I haven't "jetted" the carb yet and I figure that might be the issue with the hesitation (live in the Denver area at almost 6,000ft elevation).

After all that on to the real question... if I drive the car long enough to get it good and hot (say at least 30 minutes), if I shut off and try to start again within a short period of time (say 20-30 minutes), it can be hard to start. If I floor the pedal I can get it to start after some extended cranking. It almost seems to be like it is flooded. Any thoughts on what is causing this? My thought at this point is perhaps it is the mechanical fuel pump getting some vapor lock when sitting there hot.

Only other thing I could add is my starter does fail (i.e. doesn't crank) once in a while when trying to start hot, but when that happens if I wait a couple seconds and try again it usually will turn over. This is a less frequent and I believe unrelated problem, as it is definately cranking good when I am trying to start it as above.

Sorry for the long post to a rather short question, but any ideas as to what is causing the hard starting?

 

Your problem sounds like percolation and a 1" spacer will fix that. I've drove (and tuned) carburated cars for years out here in So cal and can't ever recall a vapor lock issue because it has a mechanical FP. Vapor lock happens because the fuel ine is too close to something hot.
Your hesitiation issue is probably due to jetting or adjustments. Note that it runs good with the choke closed thus you may be too lean. Try moving the idle mixture screws a little more rich before you do alot of jet work.
If you starter doesn't crank randomly its probably in the starter. (worn brushes).
JLG

 

for the starter a lot of original ford starters hate starting hot. maybe you have headers installed that pass close to starter heating it up. you might try with a thermoshield wrapped around it.
as towards the hesitation. check for vacuum leaks at lines and gaskets as well. I'm quite sure as well you';re running lean as jlg pointed out

Kal

 

WRT starting, I had similar problem with my 69. 302, Holley 1850. Ended up being my almost 40 yr old starter switch. Lots of intermittent starting issues. Went away totally after new switch. Also recently replaced the original starter to solenoid cable and engine to firewall ground wire which made for even stronger/easier starts. Too bad the new starter and fuel pump I tried first didn't fix.

 

Thanks for the feedback. I do have headers and will look at putting some thermoshield to help keep some heat from the starter. I will also probably just replace the starter by next spring, as I have no idea of the past life of the current unit. I will also take a look at the idle mixture and check for vacuum leaks to help with the hesitation.

As for the main issue of the hot starting (cranking but not firing), I guess I am still a little stumped. I have a spacer, but I am not sure how thick it is, so I will definately check into that. The fuel line is kept away from the engine as best as possible and routed along/under the shock tower braces. Had to reroute the line around the back of the engine when I switched to the new Edlebrock carb. I don't have much experience with all the carb settings so I might take it to an expert so I can make sure all is set up and operating properly. Not sure how fast all this will happen now that winter is upon us.