My stock 350 with Quadrajet 4-bbl takes about 10 seconds to start after sitting for a couple of weeks. Engine never rebuilt, has around 40 psi oil pressure, no smoke on startup or under hard acceleration. Choke seems to close fine just a little open, I give it about 5 pumps of gas before starting. If I use starter fluid will catch immediately but stall.

When the car has run in the last couple of hours it starts very fast like in 2 seconds, half a crank.

Any tips, thoughts on whether this is normal?

Thanks.

 

I would say that the gas has leaked out of the carburator bowl. I have the same issue with one of my old cars. You can prime it with gas or starting fluid and it should take right off, or get your carb fixed.

 

Fuel in the carb can leak or evaporate down. Esp evaporate out after a long period. Nothing wrong with the carb, ...gas evaporates. If it were overnight than it might be a leakage issue to deal with, but IDT it is in this case. My carb cars are like this too. Two weeks, that's not too bad actually. If I don't start mine for a few months they turn over longer. That's ok, for me.

I do things differently: I NEVER pump the throttle first. I turn the engine over several seconds and then stop. Wait, 30 seconds or even more (the longer it sits), then, I pump and start. My reasons for doing this are three-fold:

1) Allow fuel to fill a partially empty carb ..assuming some gasoline will evaporate out over time.
2) Allow engine to get oil pressure under starter RPM's (low RPMs) ....and get some oil flowing around and on the front/rear main seals, and around the cam lobes ...while the engine is rotating slowly.
3) Let the carb rubber accelerator pump seal (and other gaskets) get submerged in fuel and 'moistened' with fuel (by waiting 30 seconds or longer) before pumping it and starting. Pumping the carb FIRST when the rubber seals could be (and probably ARE) potentially hard and dry (from sitting 'dry'), and scrubbing the dry brittle seal in a dry bore is just going to damage and wear out/crack the potentially dry and possibly brittle seals. If you've seen seals when they aren't submerged in fuel, well, that's how they get. I'd rather give the dry seal/s in the carb a little time to absorb some gasoline and re-moisturize and become 'soft' and self-lubricate in a wet bore when I DO go to pump the carb.

I'm sure guys have different opinions on this, and some are going to say, "Well, if a seal is dry and brittle, it should be changed." But there are many shades of 'dry' and allowing it to soak in fuel for a bit can prolong having to tear the carb apart. After many years of cars sitting over winters and non-regular operation, I haven't had one accelerator pump go out for a long time. But pumping a carb with potentially dry/hard seals is asking for trouble. I used to do that till I changed my philosophy.

So... use the slow starting process of your carb car to your advantage to help with longevity. By treating it 'nice' it'll mean less maintenance (hopefully) down the road.

.

 

Thanks this sounds like a good method, will give it a try! As far as I know carb never rebuilt, it has the correct date code for a manual 1975.

 

Hypothetical question, will blocked idle tubes affect cold starts?

 

I think normal..
make your filter has the check valve in it..

manual is cold two full pumps..crank..if no start after 10 seconds, stop, two pumps…start…done

anything more i would say is an issue

 

That's just the way cars were in the 40s-50s-60s & 70s. Pump the snot out of the gas pedal or pull a choke lever and hope for the best.
Never complain about pumping the gas pedal. Some of us remember having our buddies push the car, turn on the IGN and dump the clutch in second gear.

We have become an era of "push-button-remote start" from the comfort of the house.

 

Quadrajets have a smallish fuel bowl compared to other carburetors, not surprised fuel will have evaporated out after several weeks.

 

For my stock 72 I follow the directions in the owners manual:
1) push the accelerator to the floor to set the choke.
2) push the pedal to the floor one more time.
3} depress clutch and turn igition switch
It fires right off after a couple seconds even after sitting for a few weeks.
When mine got hard to start, I rebuilt the carb and did the epoxy plug fix and that took care of it.

 

And to add some of the castings of the carbs body were very porous allowing fuel to evaporate thru them. I have the same issue. Takes quite a few pumps to get it going after sitting. Ike.

 

My Harley has a Start-Stop switch. I crank it over 3-4 seconds u til oil pressure builds...then flip the switch to Start.
It fires up in one revolution every time.
Maybe I'll put a switch under the dash on the 68 since working the Harley switch is 2nd nature after 50 years

 

Shouldn’t need 5 pumps to start , does the accelerator pump have a good squirt ?

I’m going through this on my two 1980 L82’s with stock Quadrajet, my black one starts with one pump and starts immediately. My white L82 takes a good 5 seconds to start if it sits more than two days , the same one pump , both have fresh carbs , fuel is not evaporating, fresh tune ups for both, only difference between those two are the white L82 is 66k mile original engine (does smoke at start up cold or warm) where my black L82 is 100k plus but low miles since overhauled

 

If you dont want to pump there are 2 solutions....one, get a bulb syringe and fill the float bowl through the vent because there is no fuel in there. OR three, get an electric pump as a back up for starting or to replace the stock one, fire it up and wait a few seconds to fill the bowl then shut it off. Then pump it twice as normal and start. THere are flow through pumps like the holley electric line that you can put inline to deal with issues like this. I eliminated my pump a few years ago when I went to EFI and after switching back, I just replaced the high pressure pump with a low pressure one. I may put the mechanical one back on this winter and run both. I love the priming feature the electric one provides. Never have a no fuel start like this anymore

 

After a long period without starting I crank for about 5-10 seconds.
I then slowly press accelerator pedal to floor, and release slowly.
Starts right up.

 

1. Don't touch pedal2. Crank to get oil pressure up3. # of pedal pumps inverse to temperature. Yesterday at ~ 40F probably 4 times before cranking, and another few along the way.
4. VRoom...

 

Don't forget, the OP said it takes about 10 seconds: 'After it sits a couple weeks' ..that's 2-3 to me, maybe 4. But starts right up thereafter, after it's been running. Sounds pretty normal to me.

 

Thought for you:

A new fresh fully charged battery will make a difference with better starts too. Since most C3's sit a few weeks in between runs, and the battery may be older, that does not help.

 

You shouldn't need to "pump" the accelerator to start the car. If choke is set up properly and the carb has fuel in the bowl, you should only need to "tap" the accel pedal to get the choke set for cold-start operation. Crank it and it should start. If it doesn't start after about 3 seconds, give it one pump, then try it again.

As mentioned above, the fuel in the carb bowl may be siphoning out of the bowl. If so, the bowl would have to re-fill [most of the way] before the engine could start. The solution to this is to make sure the little filter in the inlet housing of the carb has an "anti-siphon" valve built into it. They come with or without this valve.

P.S. When removing the fuel line from the inlet housing, you MUST use TWO wrenches: one to hold the hex fitting in the inlet housing and one to break the fuel line fitting loose.

 

If my car has been sitting for awhile I just pre fill the fuel bowl by putting fuel down the vent tube...make sure the accel pump is primed hit the key and fires off first time.
Saves the battery and the starter motor.

 

Thanks lots of good info here, I do keep the battery on an battery tender, just concerned about killing the starter cranking for 10 seconds. If I spray starter fluid will catch a little immediately but not enough fuel I'd guess to keep it going.