Hard starting after sitting
Thread Starter
7th Gear
Joined: Aug 2007
Posts: 7
Likes: 0
Hard starting after sitting
I have a '94 Corvette, LT-1, Manual.
The car is hard to start after it has sat for 8 hours or so. It will fire right up if it has only been sitting for a few hours.
It used to start immediately, but now you have to crank it over for 5
seconds before it takes off, and it stumbles a little at first, then
smooths out to idle. When you first turn the ignition on, the fuel
pump knocks and races for 3 - 4 seconds. The noise seems to be coming from the engine just in front of the firewall, passenger side. If you turn the ignition off (without starting it) and turn it back on, the pump runs again, but it is not as noisy. I think it is trying to build pressure back up that has been lost while sitting.
If you shut it off, it will start right back up, and you do not hear
the fuel pump run.
I think it could be one of two things:
- Fuel Pressure Regulator is not holding pressure and gas is returning
to the tank, or
- A fuel injector is leaking
What do you guy's think?
Thanks!
The car is hard to start after it has sat for 8 hours or so. It will fire right up if it has only been sitting for a few hours.
It used to start immediately, but now you have to crank it over for 5
seconds before it takes off, and it stumbles a little at first, then
smooths out to idle. When you first turn the ignition on, the fuel
pump knocks and races for 3 - 4 seconds. The noise seems to be coming from the engine just in front of the firewall, passenger side. If you turn the ignition off (without starting it) and turn it back on, the pump runs again, but it is not as noisy. I think it is trying to build pressure back up that has been lost while sitting.
If you shut it off, it will start right back up, and you do not hear
the fuel pump run.
I think it could be one of two things:
- Fuel Pressure Regulator is not holding pressure and gas is returning
to the tank, or
- A fuel injector is leaking
What do you guy's think?
Thanks!
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Attach the fuel pressure guage to the schrader valve on the passengerside fuel rail. Make sure it's on tight. Turn the key "on". Watch the fuel pressure guage. The fuel pressure will be over 40 psi and will drop a few pouds when the fuel pump cuts off. The pressure should hold where it's at for a little while. If it doesn't, then you have a leak in the fuel system. Then you find where it is.
