I found “Service Engine Soon” lights on two months ago. I checked the code (P0133) is about Oxygen Sensor problem. We continued to use this car for local shopping. One day about three weeks ago when I started the engine, the car vibrated obviously. Therefore, I turned off the engine for troubleshooting late on. When I came back to check the car a few days later, it can never been started anymore. I changed spark plugs, ignition wires, and I checked sparking for all cylinders. All of them are still firing normally. I think the problem is more related to the pressure. How do I go about further troubleshooting and solve the problem from here?
We don’t even know what kind of car you’re working on. . .
My car is Saturn SL2 2001. Thanks for asking it.
The mileage is about 120,000.
If you turn the key to the On/Run - not all the way to crank it - can you hear a 2-3 second hum of the fuel pump? If you’re not sure pull the gas cap and listen from there while someone turns the key.
If you can’t hear the fuel pump then you need to check its power - fuses, relays, whatever your system has. Also check your owner’s manual for an auto shutoff reset.
If you can hear the fuel pump I’d put a pressure gauge on it to see what you have for fuel pressure.
Thanks for the input. I will try that.
Spray some starter fluid into the intake. If that gets it going for a bit then check for a fuel delivery problem. If that doesn’t make any difference then check the compression. There may be a problem with the valve timing.
I can hear a hiss of “fuel pump” when I turn the key, but not at the fuel tank --gas cap. I tried my other car which is running normally. There was no pump “hiss” or tank pressure at all. I wonder whether I checked the right place for evidence of pumping action.
Another pressure issue is the internal pressure in the combustion chambers. I don’t know whether there is an easy way to check and fix if there is a problem.
“Another pressure issue is the internal pressure in the combustion chambers”
Are you referring to compression?
If so, why do you suspect that your engine suddenly has low compression?
Has the timing belt ever been changed on this engine? If not, is that why you suspect a sudden lack of compression?
Due to the way the engine died after it was started up I have a bad feeling about what the problem is. If I am correct then hopefully this isn’t a interference type engine.
To check the cylinder pressures you need to remove the spark plug mounted in the cylinder you want to test and connect up a compression gauge in the spark plug hole to measure the pressure when cranking the engine.
Well, he (or she) didn’t say it died, he shut it off, and hasn’t been able to start it since.
But I agree with you…doesn’t sound hopeful.
If you don’t have one or have a friend who has one, call your local Autozone or the like and see if they rent out “compression test kits” and whether it will fit your car. Hopefully either you can do it, or con a friend into helping you get the test done. That will tell you alot about the internal state of the engine. Following successful compression test, you can go on to test, troubleshoot and fix whatever else may be wrong.
You should be able to pull a plastic cover on the front of the motor and see if the timing belt is at least still more or less intact. Since it’s been turned over, if it’s broken, the damage is apready done.