I have a 2001 Saturn SL 1.9L SOHC 5 speed. I have taken it to Auto Zone & Advance and no codes are showing(they say that's because the check engine light isn't on). The problem is the car is flooding. This never happens when the engine is cold, each time it happens the engine is warm and has been recently driven. This has happened at least once a day for this past week, prior to that it was only occasionally. When you try to crank the car the motor turns over and it sounds like it's gonna crank and then it sputters out. At that point you can try up to 30 min before it finally cranks. Usually by then I have to hold the gas pedal to the floor and black smoke rolls out. Other than this flooding issue the car drives perfectly. No other problems other than terrible gas mileage w/this flooding issue. Does anyone have any suggestions, please?! A friend suggested changing the oxygen sensor, MAP sensor or an engine temp sensor. I don't have the money to replace all this stuff right now so if anyone has any suggestions to narrow this down I am greatly appreciative!!

 

If it were my car, I'd replace the Engine Coolant Temperature Sensor (ECTS), and it's associated electrical connector. Total cost for parts will be about $40 usd. That sensor adjusts the air/fuel mixture of your engine, based on the temperature of the coolant - if it doesn't work right, the system goes all to hades, and your fuel mileage goes there too ....

 

Thanks for that info! We changed that sensor last night and so far the car is cranking good. The only drawback is that it doesn't "flood" every time I try to crank it. Sometimes I could go a couple days without it "flooding" at all and then all of a sudden it would act up again. Hopefully that sensor will solve the problem. One thing I did notice right away was the temperature gauge was running higher. I've owned the car for 2 years and the temp always runs about the first line (like on the quarter tank line for gas) and as soon as we changed the ECTS sensor the temp gauge is now running right at the half way line. Is this normal when you change this sensor?

 

yes --the PCM derives the coolant temp from the ECTS; the gauge is also driven by the ECTS.

1/2 way between 1st n second tick to 2nd (middle) tick is normal

 

When it floods, there is a trick, hold the gas pedal to the floor for thirty seconds, then with the pedal still on the floor, crank the engine. It should start within a couple of revolutions of the engine, then let up off the gas.

Most often the flooding is caused by pushing on the gas pedal during the start cycle. In the old days (carburetors), you had to press teh gas about 1/2 way during the start cycle to set the choke. FI engines meter the fuel during the start cycle only with the pedal all the way up.

Holding the pedal to the floor sets another override that stops any fuel delivery during the start cycle in order to clear any excess gas in the manifold.