hot start and timing woes
 

I have a friend who has a newly 'rebuilt'(soft seals) street ported motor with stock carb, no rat's nest, full rb exhaust... Well his car starts fine when cold but once it gets hot forget about cranking it. It didn't start doing this until about 2 weeks ago, and we're stumped as to what to do.

We tried using a timing light when we did have it running but we couldn't get signal! light is good because we tested it on my SE.. we've tried moving the dizzy up and down a tooth but no help.. new plugs, rotor button... also when spinning it over to try and crank it if we give it any gas the spinning slows down.. any ideas?!

I'm thinking compression issues..

If the timing light isn't working on his car, but does work on yours, then the first thing I would suspect would be a loss of ignition on his car...

if it was compression the car would have a hard time starting to begin with, and considering it just had a "rebuild" one would assume everythings in ok condition. So.....have you determined that you have spark once you attempt to restart the car while warm?

Perhaps, when the key gets turned off the bowls empty into the engine causing it to flood once you try to start it. It happened to me a bunch after I rebuilt the carb until the needles got broke in.

like ian said....when its warm, check the front sight glass on your carb. the fuel level should be at the half full mark. this may help you if its a carb problem. how long after its warm can you start it? how long does it take to start and what color smoke do you see coming from the exhaust when you start the car?

Just so I can get the distributor out of the way, what's a sure fire way (hehe) to know I have it in right? We've set the pulley to the leading mark, and I normally just have the arrow on the rotor button pointed to the radiator.. How can I get it right?

I'll check back in this evening with answers to all that, gotta get out of work first..

With the timing problems, I'd guess something electrical or ignition, but if nothing else is wrong, try a compression test. Low compression will affect hot starts more than cold starts.

Did all of the hard seals go back in the same spot they came out of? If they didn't, you have a semi-new motor that needs to be broken in like it had fresh seals.

Next time it's hot and refuses to start, pour a little motor oil down each barrel of the carb.

Slashdawg is right on the engine having less compression when hot. Do a compression test, both hot and cold.

oh yea about the timing light, even after we get the car crunk it shows no signal, had great connection to the battery... But here's the summary:

-Cranks up great when cold
-After it heats up, carb won't idle
-Almost impossible to recrank

I've pulled the fuel pump fuse trying to see if maybe it was just flooded but it still won't crank. will check the carb when i go over there again.. any word on setting the distributor? (begins to use search button again)

edit: We have poured some atf in the carb and it does help it crank up, though not much better. the hard seals didn't go back in the same places, he used 3 different sets of the same year 12A and picked the best of the litter...

bubbles in the radiator.. is that normal if it's just water and the car is at operating temp? little fizzy bubbles, if ya know what i mean..

Uh-oh. Champane bubbles in the rad is a blown coolant seal. That could explain the hot starts and idle too. Sorry, it sucks, but you will probablyu need to tear it down again.

Tiny bubbles DON'T make me happy: the anti Don HO version.

I have a smililar hot start problem and can't figure it out. I have to basically purposely flood it just to get it to start after 5 or even 10 minutes of sitting off after warming to operation temperatures. If I let her sit for about 20 or more minutes she starts okay. Any thoughts?

If the timing light still won't show any spark, then you probably don't have any...

I agree. What kind of light is it? Is it the kind that you put in series with the plug wire or the kind that just clamps onto the wire.