New member 1966 Newport.. 383 question

[Corvetteman115]

Hey guys so I'm new to the forum I'm 30 years old and I've had a handful of classics before (including a 69 Monaco) the difference was before I had my dad to bounce questions and ideas off of (he was a life long molar guy) he passed away back in June so I can't do that anymore.. I just picked up an immaculate 66 Newport with a 383 2barrel.. all stock.. engine rebuilt a few years ago and you can tell by how clean it is.. however I noticed it runs great however when it's warm if I turn it off and turn it back on it'll idle alittle low and shake as it's idling, then I give it some gas and it smooths out.. should I be looking at ignition timing, vacuum, or just set the idle up alittle bit? Not sure which direction to go, it doesn't do this all the time and doesn't do it when cold.. only when hot after it's been sitting for a few min then when turned back on and as I said once I give her some gas she starts running fine again

 

[GJS]

I'd suspect underhood temp when hot starting... esp if it's prone to this in hot weather compared to cooler weather. What does your temp look like when you start up?

Also, warm it up to the temp you would normally then shut down and check your choke plate.. depending on what your choke mechanism is, it may be closing a bit in that down time causing a rich mixture when starting.

 

[rexus31]

I've found this excerpt from THE CARBURETOR SHOP / Troubleshooting helpful:

HARD STARTING, HOT

Difficult starting of a hot vehicle from 5 minutes to an hour after the engine has been operated, can be caused by the volatility of modern fuel. If you have this problem; try using the following method to start the engine: DON’T touch the footfeed (VERY important). Crank the engine over from three to 5 seconds (different vehicles will respond to different times); and then GENTLY (so as not to activate the accelerator pump) press the footfeed approximately 1/3 of its travel. The engine should start, and may run rough. Run the engine at a high idle for about 10 seconds. This issue is caused by volatility of modern fuel. Once the engine has been shut off, the gasoline is heated by the latent heat of the engine, and percolates the fuel from the bowl into the throttle area, forming a mixture that is too rich to fire. If you push the footfeed to the floor (as has been the traditional method of “unloading” a flooded engine) the gasoline continues to flow into the engine (again due to the volatility). By not touching the footfeed, you do not open the throttle plates, and the engine will pump the overrich mixture out of the tailpipe. Once the overrich mixture has been alleviated, gently opening the throttle will allow the engine to start.

 

[stubs300]

I have to treat it as a flooded condition.

 

[Turboomni]

The carb is a tea kettle on a stove. Same problem here. Even tried ethanol free gas. Maybe a little better but not much. Leaded racing gas was abit better than both but it is 8+ bucks a gallon.

 

[Turboomni]

DON’T touch the footfeed (VERY important). Crank the engine over from three to 5 seconds (different vehicles will respond to different times); and then GENTLY (so as not to activate the accelerator pump) press the footfeed approximately 1/3 of its travel. The engine should start, and may run rough. Run the engine at a high idle for about 10 seconds. This issue is caused by volatility of modern fuel.

I will try this though.

 

[Corvetteman115]

Thanks guys but maybe I didn't word my question correctly.. it's not that the car won't start when warm it's that it will start but idle very low and jerky.. then I hit the gas and it'll rev to about 1k and stay there (almost as if it were cold) then I hit the gas again (like when it's cold) and it settles and idles fine after that

 

[rexus31]

Thanks guys but maybe I didn't word my question correctly.. it's not that the car won't start when warm it's that it will start but idle very low and jerky.. then I hit the gas and it'll rev to about 1k and stay there (almost as if it were cold) then I hit the gas again (like when it's cold) and it settles and idles fine after that

That's because you have an overly rich condition and running the motor as you described clears out the excessive fuel. Following the steps I've outlined should mitigate the issue.

 

[traintech55]

Very nice suggestions, BUT I would put a vacuum gauge and a Dwell / Tach on it and check you base idle mixture adjustments. Remember this HAD to be done on older cars periodically.

 

[pomonamissel]

todays gas and heat raiser passage under the carb is an issue . i've been blocking them off and going to electric chokes on my four bbl cars . and layering gaskets and thin metal spacers between them under the carbs to hepl stop heat transfer from the engine . one solid spacer doesn't do the same as muti layering .

 

[66sptfry]

Welcome

 

[70NEWYORKER]

Vacuum advance hooked up to manifold instead of carb?

 

[pomonamissel]

me no run advance with this dizzy , but the chrysler electronic dizzy does vac off the carb . msd mounted inside for a cleaner old school look .

 

[moper]

I think it might just be a case of simple maintenance and tuning. If you don;t have a manual, get one. Check initial timing, point dwell, floats, choke settings, etc. The new fuel can cause problems but unless it's high 90s and the engine is heat soaked it should not be too bad. It may also be a simple 1/4 turn of the mixture screws out would cure it.

 

[Corvetteman115]

It was low 90s the day I noticed it. I just got this car last weekend (traded my 56 Buick for it) it's absolutely immaculate for a driver car, it's been repainted in its life but the interior is all original and close to mint, previous owner told me motor was rebuilt a few years ago before he got it by the 84 year old who bought it new (he got it from his daughter after he passed away) I have about $4,000 worth of receipts for things that have been done to it over the years but I haven't had a chance to go through them yet. I also have the original owners manual and the dealers brochure from 1966, it even has the factory metal warranty card in the slip on the front inner wheel well.. I do need to buy a manual, I need to start working on my own cars again, I always used to but the last few years It's been easier to pay someone but with limited funding and owning a 51 year old car..I'm going to have to start working on my own stuff again. Thank you for all the replies I can already tell I'm going to be comming here a lot

 

[Corvetteman115]

Here are a few pics of her

 

[live4theking]

That's a beautiful car.

 

[MarPar]

beautiful!!!!

my .02 on your issue, choke is sticking.

 

[GJS]

View attachment 136691 View attachment 136692

Here are a few pics of her

Congrats on that girl.. what a looker!

 

[commando1]

Drop dead gorgeous! Doesn't need the fuzzy dice.