Always takes 3 tries to start...

[ladams]

Since I have owned my '81 I have had a constant problem in starting it when "cold". It NEVER starts on the first try and always takes 3 attempts to start. I have had my share of old cars and usually you just have to pump it before cranking and that solves the problem. But for some reason, my vette almost behaves the way a fuel injected car would and pumping doesn't have much affect. It is perfect after it warms (except for the starter which lags sometimes from what I suspect is overheating from the headers).
Any ideas?

 

[minifridge1138]

I have a smiliar problem with my 1982 (i've converted it to a carb).
If I pump the pedal 2-3 times, it will start, but if i don't feather the gas, it dies.

I just assumed that the car sat long enough for the fuel in the carb to evaporate. So the engine had to crank long enough for the fuel pump to get fuel to the carb. Then it starts better than any car i've ever seen.

Maybe someone else has another thought.

Good Luck!

 

[SIXFOOTER]

Sounds like choke issues on both cars.
Things to look at:
Choke closeing when cold, it should have 1/4" or so gap at the front edge of the blade when cold and full open when warmed up
With the engine full cold, before starting or cranking, remove the air cleaner, hold the choke open and look into the throat and bump the throttle, make sure you get a squirt.
First start when cold: depress the throttle about half way and let off, this allows the choke to close as it will be held open and squirt a little gas into the intake. Then turn the key and bump the gas at the same time

 

[White75]

I usually start it cold with 2 pumps while I'm cranking it over and then stop. Then I crank it again with a small amount of gas to get it going.

 

[KANE]

Since I have owned my '81 I have had a constant problem in starting it when "cold". It NEVER starts on the first try and always takes 3 attempts to start. I have had my share of old cars and usually you just have to pump it before cranking and that solves the problem. But for some reason, my vette almost behaves the way a fuel injected car would and pumping doesn't have much affect. It is perfect after it warms (except for the starter which lags sometimes from what I suspect is overheating from the headers).
Any ideas?

Huh. Well, mine starts quickly each and every time I turn the key over.

Sounds like you need one of these-

Yeah, yeah... old pic with 27 year old dirt OEM dirt on it!
Anyways, I've been too busy doing this and this lately to get any new pics... I've driven the '80 to work almost everyday for the last two months!

 

[ladams]

I wish!

It took 10 years just to get the car, you think I can talk wifey into doing something like that?!?!?! lol

 

[6880 Mike]

...Sounds like choke issues on both cars...

I agree.

 

[Vette79]

When cold I usually have to pump the gas pedal 4 times in order for the Vette to turn over and start. My choke works and it does squirt fuel on first try when cold. Interested to see how this post turns out.

 

[TWINRAY]

My '69 never starts on the first try but the '67 does. I would tend too agree that it is a choke issue but I've never delt with it and attribute it it's personality:L

 

[minifridge1138]

Minor update on my situation.
This only started happening AFTER i tuned my carb.
A few months ago, my car was running WAY too rich and idling way to high, but it started with the slightest turn of the key. I didn't even have to pump the pedal.
Now that the mix is set correctly, and i have the idle barely above the stall point, it doesn't start as fast.

Good Luck!

 

[6880 Mike]

...This only started happening AFTER i tuned my carb. A few months ago, my car was running WAY too rich and idling way to high, but it started with the slightest turn of the key. I didn't even have to pump the pedal. Now that the mix is set correctly, and i have the idle barely above the stall point, it doesn't start as fast...

Sounds like you leaned her out too much.

 

[minifridge1138]

She runs great and the idle is nice and soft.
I adjusted the mix with a vacuum gauge and tuned it until I was get a nice steady vacuum.

I can get it to start on the first try, it just takes some play with the pedal.

Thanks!

 

[KANE]

... I adjusted the mix with a vacuum gauge and tuned it until I was get a nice steady vacuum...

Lots of guys swear by vacuum- but in your case... if you really want to see what is going on... I think you might be better off tuning with a wide-band 02 sensor. You'll get a much better idea of what is happening so you can get as close to 14.7:1 mixture (air / fuel) as possible.

I think your choke is a tad bit too lean. The choke is supposed to run a little rich when cold. If I remember correctly- GM sets the choke two clicks rich. You also have a fast idle cam you can set. You set both of these on the choke assembly and they are independent of the two mixture screws.

 

[Vette79]

I found that my idle mixture screws were 7 turns out. Too rich. I am at 4 turns out now and she seems to run fine without fuel puking up out of front of carb. DarkShark, isn't the black disk that you turn on a hot-air choke used to set how long the choke stays engaged. Not for lean or rich. Right now I am all the clockwise.

 

[KANE]

I found that my idle mixture screws were 7 turns out. Too rich. I am at 4 turns out now and she seems to run fine without fuel puking up out of front of carb. DarkShark, isn't the black disk that you turn on a hot-air choke used to set how long the choke stays engaged. Not for lean or rich. Right now I am all the clockwise.

I dumped carbs a while ago... yes, you are right- it doesn't affect the gasoline side of the equation but rather inbound air.... the setting essentially determines how long it runs for and therefore how rich by the duration. The technical nature is this: the choke increases the richness by acting upon the inbound volume of air- not with the gasoline itself.

Thanks for keeping me strait.

Congrats on getting your carb where you want it!

 

[Vette79]

Anyone think 7 turns out on the mixture screws is way too much? I know you start at 2 turns out as a base and then work your way out to achieve max vac.

 

[JohnZ]

Anyone think 7 turns out on the mixture screws is way too much? I know you start at 2 turns out as a base and then work your way out to achieve max vac.

Seven turns out is WAY out of whack; the idle mixture passages must be really gummed up. You should be able to achieve highest steady vacuum around 1-1/2 to 2 turns out from lightly seated.

 

[Vette79]

Thanks, John. I am at 4 turns out right now. The Quad was rebuilt the end of last year. She screams with no major issues. 7 turns out obviously was my problem with fuel bubbling up out of the front of the carb every once in a while.