synoptic12

Looking for a possible answer regarding the start-up procedure of a 1986 Oldsmobile Cutlass Supreme Brougham (307 Y) 5.0 Liter with a Rochester four barrel. I've owned the car new from day one. If I drive daily, I do not even have to depress the accelerator to start immediately. If I let the car sit for a couple of days or more, I have to depress the accelerator a couple of times to start > longer cranking period. Could any provide any insight here regarding the aforesaid? All replies are welcome.

Fun71

The gasoline in the float bowl evaporates through the vent tube after several days of sitting, so the engine has to crank a few times so the fuel pump refills the float bowl.

Koda

Like the man above said, the car has a carburetor. The owner's manual should have some information.

Usually:

Warm start: depress some 20%, hold, crank, should fire immediately.
Cold start: depress fully once, then hold 20%, crank, should fire on first crank.
Several days or more cold:, pump a few times fully, then foot off gas, crank to start, may take several seconds.

synoptic12

*Thanks very much. Believed that to be the issue. You have clarified it.

synoptic12

*Thanks much, most appreciated. Sometimes I believe I have fuel injection. Moving from one car (Challenger- fuel-injected) to Olds'. I still prefer the Olds'. I believe you're 100% on point with your facts.

Tedd Thompson

The reason You noticed a difference is our gas now has about 10% alcohol in it and evaporates quicker thus the fuel pump has to fill the float bowl sooner than when we had ethanol free gas..... Tedd

synoptic12

* Not adept with alcohol content but certainly makes sense. I really, really like that lady in the car, most becoming.

cjsdad

You should search through Tedd's threads and find his story about it. It is well worth the effort.

Tedd Thompson

Take a look at my album if you like her, she was very cute in person. No relation or relationship and that was the first time I had ever met her. She is a model who worked for a photographer that does photo shoots for a aircraft magazine, vintage cars and bikes with aircraft in the background. I was lucky to be asked to do the shoot...... Tedd

Schurkey

Sounds like the idle is overly-rich, or the choke is partially-closed. Perhaps all the evaporated fuel is still in the intake system. You should need to tap the gas pedal to set the choke for starting, even when the weather is warm. Typically, warm-weather starting needs little more than 1/8 throttle--just enough for the fast idle cam to clear the fast idle screw so the choke can close. As the weather gets colder, you'd need to press the pedal further, or even press fully, to add accelerator pump shot fuel to the intake manifold. At -20F, it may take a couple of full pumps. (but this assumes that there's fuel in the float bowl!)

Depressing the pedal once sets the choke. Extended cranking brings fuel to the carb which is probably empty. You could test for that by removing the air cleaner lid and pumping the throttle linkage; if you don't have a decent accelerator pump shot each time you open the throttle, either the accelerator pump is defective...or the carb has no fuel in it. No fuel is common.