My 1999 Chevrolet Prizm will not start after sitting outside for 12 months without being started or driven. It turns over nicely. There is gasoline in the tank. It will start and run briefly when I put gasoline into the intake. The mileage is 112,000. I purchased the car new. It has never had any problems or been repaired. It was starting and running fine when last driven. Should I be able to hear the fuel pump running when the ignition key is turned on? I don’t hear it. Any suggestions for me? Thank you.
You just answered your own question yes.
1 Like
You may hear the fuel pump for approximately 1 second, power to the pump will stop after that if the engine is not running.
While someone is cranking the engine, pound on the bottom of the fuel tank in an attempt to free the seized fuel pump motor. The engine may start but the fuel pump is no longer reliable.
2 Likes
After sitting 12 months unused, I presume you charged the battery at least 12 hours with a shop battery charger, right? And verified the battery voltage measured close to 12.6 volts afterward.
If the battery is not the problem, then the fuel system is next in line as the culprit I’d guess. Especially since the engine starts briefly with gasoline sprayed into the intake . (BTW, it is safer & easier to use a starter spray product rather than gasoline for that experiment. )
I own an early 90’s Corolla, and I don’t ever hear the fuel pump running w/the key “on” but engine not started, unless I’ve been doing some fuel system work and had to depressurize the the fuel system. The fuel system is designed to not allow the fuel pump to run unless the engine is rotating, done for safety purposes. I’m able to power up the fuel pump (for testing purposes) using a special test connector in the engine compartment. I doubt that method was provided for 1999 models, but it might be possible using a shop scan tool. That’s probably the approach I’d take w/that problem, see if there’s a simple way to sure the fuel pump is still working. An alternative is to measure the fuel rail pressure during cranking, not a beginning diy’er job though.
Remove the gas cap and take a whiff at the filler neck.
Does it smell like gas?
Tester
3 Likes
Yeah, that was my first thought. I bet the gas has gone bad, or at least it’s gone stale.
1 Like
Is there a switch somewhere in the fuel system that tells the fuel pump not to run unless the engine is rotating, and could that switch be stuck in the “don’t run” position after sitting so long? Thank you for your help.
Unlikely. How that all works varies car to car. On my own Corolla the ECM (engine computer) outputs a signal when it senses the engine is rotating (using sensors in the distributor), and that signal turns on the fuel pump relay. On my prior late 70’s VW Rabbit the fuel pump relay itself had the electronics that sensed if the engine was rotating, the signal caused from the opening of the ignition points. The Corolla’s fuel pump relay is called the “circuit opening relay”, presumably for that same reason. In any event, in your case it seems pretty unlikely the fuel pump isn’t being turned on b/c the circuitry isn’t sensing the engine rotating. Much more likely if the fuel pump isn’t working, it is b/c it is stuck.
Yes.
It’s called the crankshaft position sensor.
When you turn the ignition switch on, the computer runs the fuel pump for a second or two to prime the fuel system and build pressure and then shuts off.
Then when you turn the ignition switch to start, the computer looks if the engine rotating thru the crank sensor, And if it see’s it is, the computer operates the fuel pump, injectors, and ignition system.
Tester
1 Like
Yes, it smells like gas. I put in a couple gallons of fresh gasoline just in case my gas gauge was not being accurate. Thank you for you response.
Can a fuel pump get stuck just by sitting unused for so long? Is there any way to unstick a stuck fuel pump?
Yes. See Nevada’s post number 2 above. Nevada is an actual professional mechanic and, while a little cranky at times, seems very car-knowledgeable. . I’m just a driveway diy’er. I admit I’m a little cranky at times too … lol …
Thank you. I will give it a try.
Thanks again. I will give his suggestion a try.
Can my GM Dealer diagnose a bad crankshaft position sensor with his test equipment?
Yes.
Tester
This indicates that you have spark but no fuel. The fuel pump may have seized, this occurs after periods of storage with old fuel.
The fuel pump is accessible under the back seat.
Thank you.
I used to carry a five pound hammer to bang on the gas tank to jar the pump to work again. Sometimes yes, sometimes no.
Did you bang on any particular spot on the tank? Did you ever replace the fuel pump?