1997 TJ: Could my fuel pump be bad?

E

emtchrisbishop

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Joined
Oct 13, 2019
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46
Location
Missouri
Hello,
I have a 97 TJ and it wouldn't start. Battery dead and old so I replaced and tried to start it. It started and died right away. There is a whine in back near the gas tank and it will not stop unless the battery is disconnected. Any ideas?
Thanks,
Chris
 
Reconnect the battery and if the whine is back, pull the fuel pump relay and see if that stops the whine. That would at least confirm it's the fuel pump making the noise. But even a defective fuel pump should not stay running if the engine isn't running. If the engine doesn't start after turning the ignition switch on, the fuel pump is supposed to automatically shut off 1.8 seconds later.
 
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Well here's an update.

I started dropping the tank and was going to clean up the tank and pull the pump. I got it dropped, cleaned up and after a few days I got a wild hair to put it back in place and try it again. I have more time than money... To my amazement it started and ran fine. I drove it for 5 days and today when I go out to start it it is dead. When I tried to jump it I'm back to the old (will start and run for about 6 seconds then die).
Man I'm stumped. The relays are working I'm assuming. I can hear that whine from the pump when I have a relay in and when I remove it the sound stops.
I'm charging the new battery back up in the meantime.

Wonder why a brand new battery was dead after 5 days? Do you think I have a bad alternator that could be causing the fuel pump constant whine and battery drain?
 
Your fuel pump should only run when the engine is running or for 1.8 seconds after you turn the ignition switch on, after which it is supposed to shut itself off. If your fuel pump runs continually you may have a faulty fuel pump relay, faulty ASD relay, or a wiring issue in one of those two circuits.
 
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I pulled the relay tray up and made sure there wasn't any corrosion under it. Haven't the foggiest on how to troubleshoot to find that fault. Come to think if it I do remember hearing clicking come from the relay panel when I hooked up the new battery.
 
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