Okay I'm puzzled by this. Fuel pumps keep going bad. On the 4th one gone bad in past month. Expensive habit. Checked voltage going to fuel pump and it reads 5 to 9 volts. Added one yesterday and cycled it twice to get fuel into system then it quit. Replaced relay. Any suggestions would be appreciated.

1997 Chevy Blazer
6 cylinder 4.3 Liter(I think)

 

Have you been replacing the fuel fiter also? If not I would suggest that you do. Seems very odd.

 

I should check my spelling. Fuel filter

 

Dejonga,
You most likely have a bad ignition switch in your truck. When your truck doesn't start next time look at your dash cluster lights and see if they are on or off (idiot lights)
Keep us posted on your findings

 

I would check a couple of things... definitely a new fuel filter which isnt expensive at all, and I dont know how old the one in your truck is, but if its clogged it might cause other issues. I would also have the injectors cleaned or put a bottle or two of cleaner through your system. I would also check for any kinks in the fuel lines... better be safe then sorry right?

 

Alright guys, I havve changed the fuel fiter last time I changed the fuel pmp. When I turn the key the dash lights do work. I'm going to check the fuel lines next. The fuel pump kicked on when the tank was lowered and once we raised it it stopped so I'm thinking there could be a line crimpped. Any other ideas keep me posted. I'll let you guys know what I find out.

 

Double check all the electrical wires and connections going to the tank.

 

Yeah, test the voltage at your battery, if you don't have close to the same voltage (within a few tenths) at the pump, you have a connection problem. It is possible that the electrical wires have cracked or are shorting out.

 

A short to ground would blow a fuse or there would be 0 volts at pump. A short to another circuit
could reduce the voltage to the pump by bypassing current to the other device.

9 volts at the pump to ground can indicate a poor connection in the wiring to the pump.

A poor ground would give 12 to 14.7 volts at the positive terminal of the pump and
a high voltage at the negitive terminal of the pump.

Have fun searching and advise your results.

Ex electronics field service tech and trainer. Since the plug in connectors are not gold plated
in cars they can oxidize and cause a higher resistance that reduces voltage at the pump.
My ex company always used gold plating for all plug in contacts and they lasted for many decades
in all kinds of polluted industries. Gold does not corode.

I believe to restore a new car in 20 years will require replace all wiring from the hot rod industry, IMHO