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Old 07-22-2004, 08:18 PM   #1
68_Step
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Question Fuel Pump problems?

On the way back from town last night she died on me. One small backfire and the motor quit. I popped the hood and the fuel filter (clear type) was empty so I thought I ran out of gas (gotta fix that fuel gauge!). Put about 4 gallons in and it still will not crank, fuel filter is still dry. This problem is on a 78 Chevy, 1ton, 454, with dual tanks.

Is this probably a dead fuel pump?

Could the problem be with the "crossover switch" (not sure of the proper name) that controls which tank the fuel is drawn from?

Any other ideas about troubleshooting this?

Last question: When replacing the fuel pump, do I use RTV or just a gasket?
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Old 07-22-2004, 08:59 PM   #2
franko72
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If the crossover switch is a solenoid type, I have had them go bad and be stuck at the in between position. learned that after i replaced a good fuel pump.Sounds like a bad fuel pump though.If your fuel pump supply line has a rubber connection in it somewhere, disconnect it and add enough hose to place it in a gas can to check if the pump is working or if the line is blocked somewhere
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Old 07-22-2004, 09:56 PM   #3
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not sure if this helps but when my pump went out my truck died but would start back up after several cranks (you said yours didn't though) I'd get a few blocks then it would die again. this happend several times until I made it to a gas station (my gauge didn't work either) filled her up and the same thing a couple more times until it just wouldn't fire up anymore.
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Old 07-22-2004, 10:33 PM   #4
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if its the fuel pump do yourself a favor, run down to the parts store and buy a electric pump . my 2 cents.
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Old 07-23-2004, 07:32 AM   #5
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Dion: After getting it to the side of the road, I was able to crank it for a few seconds at a time... did that 3 or 4 times and then nothing after that.

Frank072: Great idea, will do that tonight.

If I disconnect the supply line from the fuel pump and fuel startes to pour out the disconnected line, wouldn't that let me know the crossover switch is working?

If it is the pump, are electric replacements better that the mechanical stock? Where are thay normally mounted (on the firewall)? Hose routing?

Thanks!
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Old 07-23-2004, 05:28 PM   #6
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ttt
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Old 07-23-2004, 05:48 PM   #7
Maximum Overdrive
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Not sure if I read this right but you got it to crank 3 or 4 times and then it wouldnt crank at all?

If you can get it to crank dump gas in carb and start truck. May take once or twice but that will tell you if you are getting gas to pump, as after a couple times gas should be in filter. Some pumps take longer to get fuel up from the take when they run dry than others do.
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Old 07-24-2004, 06:36 AM   #8
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Maximum Overdrive: I think those three or fours "cranks were just me sucking the fuel bowls completely dry. I did pour gas in the carb to try to help the process along, no luck.

I will work on it after I get home from work tonight.

For the fuel pump gasket, sealer or a bare gasket?
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Old 07-24-2004, 11:36 AM   #9
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If you did run out of gas and might have lost the prime, I have removed the coil wire from the coil and disconnected the fuel line from the Carb. Have someone crank the motor while you place your thumb over the end of the fuel line. Use the on and off release method with your thumb to let the air in and out of the line to help the pump reach its prime.Watch out for gas on electrical parts.
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Old 07-25-2004, 10:54 AM   #10
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On the fuel pump gasket I have always just used the gasket bare and never had a problem.
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