QuestionHi, I have a 1996 blazer 4X4, 4.3l eng. now on this lucky Friday the 13th cranked, but did not start, battery seems to be ok), my husband sprayed starting fluid into throat-no problem starts no problem. He added water remover, and fuel injector cleaner into gas tank. Now depends when, lately I need to turn key few times before it starts, when wont start-I spray starting fluid. Friend told us - needs new fuel pump, because when starts does not accelerate in first moment. Do you think could be that problem, or something else? It's funny, but when we use battery charger to start, no problem, starts easy)
The cost to replace the fuel pump is high, can my husband replace by himself?
Is it any relay we should consider to check first?
Thank you for the advice.
Elizabeth
AnswerHello Elizabeth,
Good news...it isn't the fuel pump. If it were the fuel pump, it wouldn't start, but it wouldn't run either.
The fact that it runs after starting with fluid means the pump is running.
The pump is operated by a relay, which should operate it for three seconds when the key is turned to run, then shut off. If there is a crank signal, the relay will keep the pump running till there is no longer a crank signal, which means when you turn it off.
There is a backup system to run the pump also. This system is an oil pressure switch. Whenever engine oil pressure is present, that switch will run the pump.
It sounds to me like yours is running ONLY on the oil pressure switch. Pressure builds up while running on starting fluid, and then it continues to run.
So check the relay, and maybe even check the crank sensor. Check the wire connections to both of them, but don't mess with the pump in the tank....or the wires to it.
The reason it starts with the charger, just may be because it puts a little more voltage out, and may be making the relay work, where the battery doesn't quite do it.
Just for information, it can be changed in the driveway, but is not extremely easy, and the fuel level should be low.
Good luck,
Van
