Hard Starting - After sitting overnight
Iíve got a hard starting problem with my 88 jeep wrangler. My Camaro is fuel injected and I havenít done much work on carbureted vehicles. I donít think the problem is vehicle specific so hopefully you guys can help.
It starts hard after is has been sitting for a day. I know the carburetor is adjusted properly as well as the choke. It appears to be a fuel problem. I acts like the gas is draining back into the tank after sitting overnight. It has a mechanical fuel pump and you have to keep cranking the engine until it can pump the fuel back up to the carburetor. I usually have to crank the engine for 10 Ė 15 seconds before it will start. Once it starts I can shut it off and it will start right up again without having to crank. Once started it runs and idles fine so I donít think there is any problem with the carburetor. It originally had a Carter computer controlled carburetor which sucked so I swapped it for a Webber carb. The Jeep runs much better but still has this starting problem after sitting overnight. The original setup I think was similar to the carburetors in the Camaro. It had a computer and emissions stuff, O2 sensor, egr, charcoal canister, AIR, etcÖ Iím wondering if the fuel pump is bad causing the gas to drain back into the tank.
I also was wondering if the problem might be with the gas tank. Is the tank supposed to be pressurized in a carbureted vehicle? In the summer time, after I drive the vehicle, if I take the gas cap off you can hear all this pressurized air escape from the take. Is it supposed to have this pressure in the tank? Is that what keeps the fuel from draining back into the tank when the vehicle is not running? If so, then maybe the gas cap is bad because the seal leaks and you can hear the air escaping after the engine is turned off.