Engine dies when hot.

[Hal9000]

So I'm just getting my '69 w/ 302 running after a long, long, hibernation...

The engine starts with difficulty right now. I basically need to use starting fluid every time when it's cold. But once running, the idle is stable and it revs nicely.

At the engine warms up however, it developes an ever worsening off-idle flat spot that eventually gets so bad that you can't open the throttle without the engine dying. And it gets harder and harder to re-start as it warms up. By the time the temp reaches 190, I usually can't get it to re-start.

Also, I've found that I can't ever open the choke all the way or the idle gets choppy and deteriorates till the engine dies.

The engine has a Holley carb. I think it's the standard 650 cfm 4bbl that everybody used to use, but am not 100% sure.

If anybody has any ideas on where I should start, or what might be the problem, I'd love the help.

 

[SteveL]

I just got mine running after a long nap. Mine was hard to start and idle was way high. I just got it going and soaked the carb with some carb cleaner and and checked for stuck parts. Now it starts fine and idles right. I would also check your fuel filter if you have one up top.

 

[Explorer]

My guess would be the idle mixture circuit is dirty and gummed up. I agree, pull it and clean, rebuild kit is pretty cheap.

 

[Rockin69er]

Every Holley carb HATES to take naps. In my jet boating days all my friends had me rebuild their carbs in the spring. Just sitting over the winter will shrink the old cork gaskets. The newer carbs and rebuild kits have the nitrile gaskets that last longer but even microscopic pieces of dirt make a Holley miserable. I love Holley carbs but you have to keep the fuel CLEAN. All the smart folks before me think it needs a good bath and I agree. Rubber duck optional.

 

[Hal9000]

Thanks guys... My cousin just quit his job as service manager at a dealership and opened his own shop. I've been throwing work his way till he gets on his feet. I'd normally do the rebuild myself, but I guess I'll let him tackle this as well since he swears he knows Holleys like the back of his hand.