1978 Corvette won't start
Thread Starter
2nd Gear
Joined: Feb 2017
Posts: 2
Likes: 0
1978 Corvette won't start
78 Corvette, L-48, with rebuilt Carb(Dec 2016). Won't start after sitting for a week( does turn over). Pour some gas into Carb and it starts right up. Once warm, it will start again even if left sitting for 5-6 hours at car show.
Mechanic says they checked fuel pump and line and no issues. What could be causing this inconsistent starting?
Mechanic says they checked fuel pump and line and no issues. What could be causing this inconsistent starting?
Le Mans Master
Joined: Jul 2000
Posts: 6,664
Likes: 162
From: columbia city in
let the car sit for a few days .before you try to start take off air cleaner .manually pump the carb and see if you have any fuel squrting .no fuel then your problem is in the carb leaking out .
Race Director
Joined: Oct 2008
Posts: 19,178
Likes: 1,668
From: Long Island
As a wild guess I would guess a weak fuel pump.
The pump has to refill the carb after sitting. The Carbs are vented to the atmosphere and the "new" gas will evaporate. I would ask the mechanic if the pump was pressure tested.
A sticking float can also give the same action, when you put gas into start the engine the vibration drops the float and allows the carb to fill.
A little Marvel M. Oil may help, a few OZ in the tank.
On my 80 truck it was the pump. Same issue. Ran fine , but after a few weeks no start. Not enough battery to keep turning it over to fill the carb.
The pump has to refill the carb after sitting. The Carbs are vented to the atmosphere and the "new" gas will evaporate. I would ask the mechanic if the pump was pressure tested.
A sticking float can also give the same action, when you put gas into start the engine the vibration drops the float and allows the carb to fill.
A little Marvel M. Oil may help, a few OZ in the tank.
On my 80 truck it was the pump. Same issue. Ran fine , but after a few weeks no start. Not enough battery to keep turning it over to fill the carb.
Thread Starter
2nd Gear
Joined: Feb 2017
Posts: 2
Likes: 0
As a wild guess I would guess a weak fuel pump.
The pump has to refill the carb after sitting. The Carbs are vented to the atmosphere and the "new" gas will evaporate. I would ask the mechanic if the pump was pressure tested.
A sticking float can also give the same action, when you put gas into start the engine the vibration drops the float and allows the carb to fill.
A little Marvel M. Oil may help, a few OZ in the tank.
On my 80 truck it was the pump. Same issue. Ran fine , but after a few weeks no start. Not enough battery to keep turning it over to fill the carb.
The pump has to refill the carb after sitting. The Carbs are vented to the atmosphere and the "new" gas will evaporate. I would ask the mechanic if the pump was pressure tested.
A sticking float can also give the same action, when you put gas into start the engine the vibration drops the float and allows the carb to fill.
A little Marvel M. Oil may help, a few OZ in the tank.
On my 80 truck it was the pump. Same issue. Ran fine , but after a few weeks no start. Not enough battery to keep turning it over to fill the carb.
Thanks Blue 1972. Had my mechanic pressure test the fuel pump and results were poor. Installed a new pump and car now starts every time regardless of how long it sits.
