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Starting a cold engine

 
Old 05-09-2019, 06:51 PM
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wgrea3
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Default Starting a cold engine

Hey all. Ideally, how many times should one need to pump the gas pedal when starting a cold engine that hasn't been started in a few days?
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Old 05-09-2019, 07:05 PM
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resdoggie
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Two.
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Old 05-09-2019, 07:05 PM
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Old 05-09-2019, 07:13 PM
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cuisinartvette
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Electric, manual or no choke? You just buy it?
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Old 05-09-2019, 07:20 PM
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F22
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My technique is three quick pumps and hold it open a crack. Usually fires right up.
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Old 05-09-2019, 07:41 PM
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wgrea3
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Originally Posted by cuisinartvette View Post
Electric, manual or no choke? You just buy it?
It's an automatic choke that I just adjusted ... it was not set to close at all previously. It seems to be taking 2-3 pumps for me now. Much more than that previously.
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Old 05-10-2019, 07:39 AM
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7T1vette
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If the carb is working properly, one pump is all it should take. If it requires more than that, look for issues with the carb accelerator pump and/or the choke system. Ignition system problems can also be to blame for hard starts.
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Old 05-10-2019, 08:37 AM
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Last edited by Hammerhead Fred; 05-10-2019 at 08:43 AM.
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Old 05-10-2019, 08:40 AM
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derekderek
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After it sits over night, take off the air filter hold the choke open and look in there while somebody pumps the gas. See if you see a squirt or not. Some older carbs will drain empty overnight. Some will boil all the fuel out. And hammerhead, that's the biggest link I ever saw. And it doesn't work.

Last edited by derekderek; 05-10-2019 at 08:42 AM.
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Old 05-10-2019, 08:45 AM
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Hammerhead Fred
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Originally Posted by derekderek View Post
After it sits over night, take off the air filter hold the choke open and look in there while somebody pumps the gas. See if you see a squirt or not. Some older carbs will drain empty overnight. Some will boil all the fuel out. And hammerhead, that's the biggest link I ever saw. And it doesn't work.
No doubt, I have no idea what happened between my photo upload and the post button.
The preview showed the pic but when I hit post WOW!
All fixed now.
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Old 05-10-2019, 03:19 PM
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On mine when cold overnight...one time push to the floor to set the choke, then release and not give it any gas and it fires immediately up at fast idle. If it has been more than a few weeks it takes a bit longer to fire but no change in sequence. Hot it likes a bit of throttle held open with no pumping then it fires up after few seconds of starter. Each car is likely different due to carb, headers, ignition, condition, ect. setups so recommend trying all the suggested methods here and if none work well investigate further.

Edit: After reading all of the responses, I tried hot starting without pumping or depressing the gas pedal and it works just as well. Due to the engine cam installed, I have the idle set a bit higher than normal so that may have helped.

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Last edited by Redvette2; 05-15-2019 at 09:23 AM. Reason: Updated information...
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Old 05-10-2019, 06:49 PM
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Two pumps and a slight pause 15 seconds.... lets the fuel vaporize.
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Old 05-11-2019, 12:12 AM
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No pumps. Pumping the gas is a good way to tear up your accelerator pump. On my 427, I ruined the accelerator pump Lars installed by pumping the gas before starting the car. The carb seems to evaporate the gas in the accelerator well and pumping the throttle in the dry well ruins the seal.

I turn the key and let the engine turn over for 5-10 seconds. This makes sure there is gas in the carb. I push the throttle down once to set the choke and then hit the key again. Car starts immediately on fast idle. It’s never cold here so a quick stab of the gas and the idle drops to where it should be without the choke. No need to pump a properly set up carb.
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Old 05-12-2019, 10:38 AM
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Originally Posted by maj75 View Post
No pumps. Pumping the gas is a good way to tear up your accelerator pump. On my 427, I ruined the accelerator pump Lars installed by pumping the gas before starting the car. The carb seems to evaporate the gas in the accelerator well and pumping the throttle in the dry well ruins the seal.

I turn the key and let the engine turn over for 5-10 seconds. This makes sure there is gas in the carb. I push the throttle down once to set the choke and then hit the key again. Car starts immediately on fast idle. Itís never cold here so a quick stab of the gas and the idle drops to where it should be without the choke. No need to pump a properly set up carb.
Interesting. This makes me wonder if there is an official method that GM specified for starting these cars. For instance is it discussed in the manual for these cars? If so, what does it say?
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Old 05-12-2019, 10:48 AM
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On mine, when cold, half a pump to set the choke, crank till it starts, runs on fast idle till warmed up. If it's been sitting a week or more, it just cranks longer before start. A warm engine, do not touch the accelerator, just hit the key and its running, any pumping when warm will flood it. This is how they are supposed to work and mostly did when new.
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Old 05-12-2019, 09:36 PM
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According to the Owner's Manual, press accel pedal once to the floor with a cold engine; turn ignition to start until engine starts; when engine is running smoothly (on Fast Idle), idle speed can be reduced by lightly depressing accel pedal and slowly releasing (this drops choke from fast-idle stop).
For warm engine, depress accel pedal LIGHTLY (to set choke, but NOT activate accelerator pump), then crank to start.
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Old 05-13-2019, 06:59 PM
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With nearly any stock engine equipped with a Holley and Auto divorced choke - this is what I have done for 20+ years.
If it has been sitting a couple of weeks I pull of the aircleaner lid and fill the holley bowls through the vents with a squeeze bottle. then a quick squirt into the primary throttle bores.. fires right up immediately.

If it's a restart after recent drive - just hit the key.
Engine cold overnight. once to the floor to set the fast idle/choke. -
Less than a couple of weeks- three times and hit the key.
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Old 05-13-2019, 09:19 PM
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Here are the starting instructions from my original 73.







Donnie

Last edited by DonnieP73; 05-13-2019 at 09:32 PM.
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Old 05-13-2019, 09:32 PM
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I just had a thought. Look at oil pressure gauge. Don't pump throttle until you see it start to climb.
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Old 05-18-2019, 08:16 AM
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wgrea3
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Originally Posted by DonnieP73 View Post
Here are the starting instructions from my original 73.







Donnie
Is the caution statement just saying that leaving the car running at fast idle for more than 5 minutes is bad?
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