If I smoke in my car its going to blowup.

[ngnate]

I have a 94 Olds Cutless Supreme and all of a sudden it smells like gas inside and out. The fuel mileage has dropped to half of what it was. The exhaust gives off a thick cloud of unburned fuel. The cloud is blue or white, but the engine is using no water or oil. There are no gas leaks that I can see. Under the hood when the engine is warm and the engine is revved a visible gas vapor emits from the back of the engine. If I slow down for a stoplight but don't fully stop and press the accelerator it hestitates for 5-10 seconds before it starts to accelerate. I runs a little rough but not too bad. Does anyone have any good ideas for me other than purchasing a flame retardant suit and a fire extinguasher. Thank you for any help on my problem.

[Slade901]

Yeah, you need a fireman's suit j/k

I would do these first.

1. While the engine is running disconnect the vacuum hose that connects to the Fuel Pressure Regulator. If there is a fuel in that vacuum hose, then the Fuel Pressure Regulator diaphragm inside has ruptured and it is sending extra fuel to the intake manifold. Most of them would not get burned and end it up in the exhaust system. Fuel in the Fuel Pressure Regualtor vacuum hose means that the Fuel Pressure Regulator needs replacement.

2. Pour two bottle of Fuel Injector Cleaner in the gas tank and hopefully it will dislodged any obstruction inside the fuel injector.

3. Replace the spark plugs if they have not been replaced for a long time or they may have fouled out already. Make sure you check the spark plug gap specs.

4. The CTS (Coolant Temperature Sensor) gives the computer a temperature signal to the computer. In turn the computer uses that signal to let the fuel injector open and closes. Failing CTS (Coolant Temperature Sensor). If the CTS fails, it will give out an incorrect reading to the computer. The computer controls how long to open and close the fuel injectors based on the information the CTS gives to the computer.


5. Replace your PCV valve. Or use somekind of PCV Catch Can. Search the web for the keyword "PCV Catch Can".
If you have not replaced your PCV valve, you may need to replace it. Normaly working PCV allows controlled air/oil vapor into the intake manifold. Failing PCV valve allows excess pressure and uncontrolled air/oil vapor into the intake manifold (stuck open PCV valve) or it prevents the air/oil vapor from coming through the PCV valve (stuck closed PCV valve) and ended up on the front valve cover where the breather hose is connected to the intake hose (very dirty throttle body, throttle plate, IAC).

Typical V engines have the PCV on one valve cover (usually rear) and hose then connected to the Intake Manifold. The other valve cover (usually front) is the breather hose and connected to the intake hose (it is suppose to just suck air in and then it exits to the other valve cover (rear) where the PCV is located. However, pressure within the engine forces the air/oil vapor out of the valve cover (front) and those air/oil vapor is now introduced into the intake system and causes dilute the air mixture for combustion and in the process gunk up the throttle body, throttle plate, IAC, etc.

[ngnate]

Thank you Slade. You gave alot of usefull things to look for.