Snoopysvet

I have a stock 1978 SA Corvette.
The carb was rebuilt by Lars a few years ago
I live in San Diego and am subject to California gas

When the car sit for more than a few days it is real hard to start,
either the gas has evaporated from the carb or has drained from the carb

A dose of starting fluid or cranking the engine for quite a long time will get it to start.

I was considering installing an auxiliary electric fuel pump, has anyone ran into this problem before?

billschroeder5842

Have you checked your Choke? If you have a faulty choke it could feel like your engine is not getting gas.

MelWff

did you contact Lars? he has a number of recommendations one of which is a fuel filter with a one way valve that fits in the Quad

cobrachuck

My GTO has the same issue Holley carb. Hard to start after sitting.
I am interested as well.

Iceaxe

I had similar issues. I installed an electric fuel pump and the car always starts right up no matter how long it sits.

spikebot 81

Tons of folks having the same issue no matter what carb is used. I look back before fuel injection was standard and all the cars started right up with 1 push of the throttled to set the choke. The witches brew they call gasoline is more than likely the problem IMHO. After market starter motor company's will soon be rich. I for one also plan to swap to electric fuel pump and a regulator.

gungatim

make sure you have the right filter, it has a check valve on the inlet. they sell them both ways. surprised Lars didn't put one in...

you may have other issues but no, there is no need for an electric fuel pump on a stock motor...

I assume you know to pump the pedal a few times before starting, when you do that is fuel squirting into the venturi?

even though it was rebuilt a few years ago, the pump could still have gone bad no fault of the rebuilder...

cv67

Mine has done the same thing also meaning draining after sitting awhile
new carb pump etc. Might be something to the check valve.
Dont see the harm with an elec pump to prime the system

Ca gas sucks...car runs ok til it hits 190 then doesnt want to idle never ran into this problem with any carbed car in almost 30 yrs no amount of dfiddling with the carb will cure it. Refuse to put EFI on an older car

Snoopysvet

I believe Lars uses the NAPA anti drain fuel filter on all his rebuilds

69Vett

if you have fuel peculation / heat soak, which boils off the fuel inside the Carb.
adding an electric fuel pump will indeed quickly fill the carb. back up,
(allowing the car to start)
unlike a mechanical fuel pump which pretty much needs the motor to run,
to pump up fuel pressure.
adding an electric pump is only bandaiding the real problem.
if your carb gets so hot you cannot put your hand on it, you have heat soak.
my advice is to isolate the carb. with a insulating gasket first.
they came from the factory with the thicker oem insulating gasket.

Snoopysvet

The issue is with cold starts after it has sat for over 4 days.

BLUE1972

he percolation starts when you shut off the car and the heat flows into the carb.

Some of the people here put a small inline pump in the fuel line by the tank. You don't need much of a pump. Jegs has them.

I put one on a friends truck as it sits for extended period..

Sayfoo

EVERYTHING under my hood gets too hot to touch after a run, so in my case, insulating gaskets didn't help.
My routine--key off, pump pedal 5/6 times to set the choke and MAYBE pump a little gas. Key on and run starter 4/5 seconds. Sometime it will start here. If not, pump the pedal a few more times--it now has gas in the bowl, and it starts.
Opening the hood when you park will help to cool things off. May help.

jim in oregon

Snoopy, have a 78 SA with an L48 350 engine and Rochester quadrajet.
When I rebuilt mine, I used an upgraded float and of course replaced the small fuel filter in the carb..Mine wasn't fitted for California emmisions So not sure what all they added to yours to make it compliant back in '78.
While I have not used Lars for any work..from what I have read here he knows what to do to properly rebuild the Q uadrajet carbs .
Sounds like you sent him your carb for the rebuild and he sent it back and you or someone else installed it?
Anyhow..simple stuff like the owner's manual tells us is to depress the accelerator slowly and fully to the floor..Then let off shoowly..
Then crank the engine ovver for no longer than five seconds..If it doesn't fire up, repeat JUST the engine cranking operation..DO NOT TOUCH THE GAS or pump the accelerator..
IF distrributor, plug wires, coil sparkplugs, are all properly done ANDvacuum hoses are all properly attached-functioning..the L48 should fire up..cold or hot.
It takes a bit of tweaking after carb is installed to adjust air/fuel properly..and timing setting for mine anyhow..was 15 degrees Above TDC..NOT MISERABLE factory setting..

After car has been running and warm..then shut off..?
Just a short bump-crank on the ignition fires her up immediately..IF you can find it in california..use 90 octane or better NON ETHANOL GASOLINE..Even in CA..it's probably available for marine or airplane use..Jim

jim in oregon

Here's a link for many ethanol free gasoline sources..select by state..A bunch in California..Jim

http://pure-gas.org/index.jsp?stateprov=IL
Aught to be a stcky post link for the C12,3 forums...

69Vett

first check, is there gas coming out of carb. after sitting ?
Second test, can you hold your hand on the Carb. after engine is up to Temperature ?
if No Hard starting is due to no fuel in the carb.
So either the bowls are leaking (common on Q-jet),
or the fuel boils off after shutting down.
a proper insulated carb. will actually be cold enough to cause condensation on the outside,
of the Carb. the cool fuel and air flow actually drop the carb. temperature dramatically.
(like 100 degree temp. drop). good luck !