When my car as been sitting for several hours or overnight, the engine won’t turn over the first time I try to start the car. It always starts on the second try.
I had the fuel filter replaced, but it didn’t help. The mechanic wasn’t sure what the problem could be.
Please define “turn over”, and tell us the make/model/mileage.
Do you mean the starter won’t crank the engine, or do you mean that the engine is cranking, but failing to start?
Since you replaced the fuel filter, I am guessing that it is the latter. That implies that the fuel rail is draining back to the tank while the car is turned off. There should be a check valve somewhere, likely inside the fuel pump, that prevents this from happening. Also, this may mean that that there is a small leak somewhere that is letting air in to the fuel rail up at the engine - like a dirty fuel injector, though the air may be coming up through the return line from the gas tank. If you crank the engine for a long while on the first try, will it start?
You should hear the fuel pump spin up when you turn the key to the ‘on’ position. It turns off once the system is fully pressurized. Normally, it can push all the air out of the system pretty quickly. Try leaving the key in the ‘on’ position for a few seconds before advancing it to the ‘start’ position. If that makes the car start quickly on the first try, you know that the fuel is draining back to the tank. If so, and that is your only problem, it is probably not worth the trouble to replace the fuel pump to correct it. I would just live with it.
Thanks for responding so quickly.
The engine is cranking, but failing to start. Also, I don’t know if this is relevant, but it seems to happen only when the engine is warm or in warm weather.
1990 Mercedes 300E 170,000 miles
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Engine is at cool stage (over night or after station for awhile)
Car ignition key is turned, but engine won’t turn without any sound (starter not turning) at all on the 1st attempt. The engine can always start when 2nd attempt when turning the ignition key. Anyone can help？
In addition, I have recent changed new battery and crank sensor and fuel pump relay. The starter can turn when 2nd attempt to turn the ignition key… and again this problem very consistent and it can replicated every day.
If it was my car I would clean all battery cables both ends and replace the starter relay. This is a cheap repair attempt bypassing complicated diagnosing. If the new relay doesn’t do the trick then detailed diagnosing would be next.
Make/model/year/miles/engine?
My guess there is a problem with the ignition switch.
Suggest you start a new thread, stating make, model, year, engine, transmission, and mileage.
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The transmission safety and brake interlock switches are possible. Do the brake lights work consistently? Try jiggling the transmission selector lever (presuming this is an automatic) and brake pedal during attempted cranking, might provide a clue.
If nothing obvious is found ask your shop to measure the voltage at “s” terminal on the starter during attempted cranking. terminal to starter case should measure at least 10.5 volts.
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