Starting tips,

[Mad4slalom]

Hi again, The previous owner of my 72 says he didnt fit a choke, it is a 350 with street cam and 10-1 compression built on a 73 4bolt block and 2.02 double hump heads.
carb is a 650 double pumper. I seem to be flooding it as very lumpy and rich smelling when cold and takes a while to run smoothly.it may start a couple of times then stall but Once warm it runs sweetly and idles smoothly. I was told to crank for 10 seconds to build oil pressure then give a couple of pumps on the throttle if it hadnt run for over a week Or just pump once if had been run More recently.
any advice as to the best procedure to start appreciated. It has a 160 deg thermostat fitted.

 

[Corvette]

Sounds about right. If you haven’t already, take off air cleaner and and pull on accelerator cable And see just how much fuel a dp Holley squirts in (bucket loads). It may well be you are pumping pedal too much.

 

[Roscobbc]

Squirter pump should be adjustable for fuel delivery via a small cam. Is it a 'basic' DP carb or does it have 4 corner idle adjustment?.
But as noted by Frank it all sounds about right really. It can possibly take a good 15 minutes or so for the engine to thoroughly warm-up in winter. Don't be fooled by the temperature gauge - it only reads water temperature flowing past the sensor not actual engine temperature. You might want to consider a 180 degree thermostat, especially in winter - a cool running engine is not good in terms of burning-off any internal condensation in the oil.

 

[Oneball]

Worth checking that the choke is either locked or removed or not present.

 

[hurtzcsa]

years ago I had a 383 stroker built with big cam 750 dp holly no choke horns . made 490 hp (not in a vet) when warm the engine would tick over at 1200 rpm in park .if the vehicle was parked up for a couple of weeks ,my starting procedure was
(!) wizz it over until oil pressure was built up
(2) two pumps on the gas peddle
(3)start engine not touching the gas peddle as soon as it fires feather the gas peddle and hold the revs at about 1500 rpm ,if it conk`s out don't touch gas peddle go through pressedure 3 .
when engine was running I`d sit there hold the revs for a while as I knew as soon as I put it in drive it would conk out (sometimes I`d hold the revs and 2 foot the brake and gas peddle and put the car in drive)

 

[Knodty]

I think starting from cold in any non injected car is specific to that car and you will have to try different things and see which one works best for your car.
I mine has been sitting for a week or two I pump it 2 to 3 times and it will burst into life quite quickly.
I never let it build up oil pressure, but don’t get any lifter noise, otherwise I would.
If it has been sitting for a couple of months I will pump it 4/5 times then turn her over it will normally turn slow at first then start to speed up rotation a little then if it hasn’t started by then, pump it again. And she should fire up.
If I had the car running the previous day I don’t pump it at all, and she fires up instantly. Once she has started in all circumstances just feather the throttle until she will idle ok.

 

[Roscobbc]

Not all Holley carbs are equal. Performance and race type carbs do not come with choke flaps. Because they'll most likely be double pumpers (and a double pumper by definition has mechanically activated secondary butterflies. It'll also have secondary accelerator pumps. It needs them. Vacuum secondary carb doesn't have (or need) pumps. The butterflies only open when there is sufficient vacuum to do so. Unless something is badly amiss they won't 'bog'. Start-up procedure with a DP is as Pete describes. Holley carbs (except possibly later and lower spec vac sec carbs can have jetting wildly 'out' yet still run OK and give you plenty of clues what needs doing. Some questions for OP. What sizes are the primary and secondary main jets? - what numbers are on the primary and secondary 'squirters'? - is the carbs 4 corner idle (i.e idle screw for each inlet)

 

[Forrest Gump]

OP does say that it idles and runs smoothly one warmed up so the carb set-up must be fairly good.
No choke on my Double Pumper so I have to keep on the throttle for a while to keep it running, but I like that involvement, and so do my neighbours except when I set off their car‘s alarm the other day!
If mine tries to stall I can usually catch it with a throttle pump - so more fuel. I think it’s pretty difficult to flood these big engines when cold, they like the fuel.

 

[Mad4slalom]

years ago I had a 383 stroker built with big cam 750 dp holly no choke horns . made 490 hp (not in a vet) when warm the engine would tick over at 1200 rpm in park .if the vehicle was parked up for a couple of weeks ,my starting procedure was
(!) wizz it over until oil pressure was built up
(2) two pumps on the gas peddle
(3)start engine not touching the gas peddle as soon as it fires feather the gas peddle and hold the revs at about 1500 rpm ,if it conk`s out don't touch gas peddle go through pressedure 3 .
when engine was running I`d sit there hold the revs for a while as I knew as soon as I put it in drive it would conk out (sometimes I`d hold the revs and 2 foot the brake and gas peddle and put the car in drive)

thank you,, your procedure sound right as the vendor in the usa told me the same. I was forgetting to leave the pedal alone after the two pumps . I will work on my procedure and technique.

 

[Mad4slalom]

OP does say that it idles and runs smoothly one warmed up so the carb set-up must be fairly good.
No choke on my Double Pumper so I have to keep on the throttle for a while to keep it running, but I like that involvement, and so do my neighbours except when I set off their car‘s alarm the other day!
If mine tries to stall I can usually catch it with a throttle pump - so more fuel. I think it’s pretty difficult to flood these big engines when cold, they like the fuel.

Yes , thanks for everyone’s comments, we decided that I was being a bit timid when pumping do it wasnt actually getting enough gas. Three or four big pumps now and she fires up well like some on here said they take a fair while to warm up and run smoothly. I am learning

 

[CaptainK]

I've tried a few different things on my 327 with Edelbrock carb that does have a choke. I don't drive the car often (less in these COVID times as less opportunities to go out). So if its been left for a while - month or so - I've found for me that spinning the engine over for a bit and then stopping for a few seconds, then spin it over again and it'll "catch" and I'll feather throttle until it sounds happy (second or two). Granted I have a choke so it happys itself then.
If I have used it recently (last few days / week), then it pretty much starts on the button with no issues

 

[Mad4slalom]

found

Thank s captain K.