4.3 Starter not operating fuel pump

[kaw550]

I have been dealing with this for a couple of years. I have recently found that when the engine is cranking, the starter solenoid is not supplying enough power to operate the fuel pump.

It is sending out about 8 volts to the fuel pump.

I assumed it was the starter to I brought it to an electrical repair shop where we bench tested the starter. On their bench, it would send 12V to the fuel pump post on the starter solenoid.
We assumed it was some kind of grounding issued but the starter turns the engine over without issue.

I brought it home, cleaned everything up and tried again. I am still getting 8 volts on the fuel pump post of the solenoid.

I confirmed the supply from the relay is 12+ volts. (I aslo jumped the relay).

Any suggestion? How can I further test?

 

[Bondo]

Re: 4.3 Starter not operating fuel pump

I have been dealing with this for a couple of years. I have recently found that when the engine is cranking, the starter solenoid is not supplying enough power to operate the fuel pump.

It is sending out about 8 volts to the fuel pump.

I assumed it was the starter to I brought it to an electrical repair shop where we bench tested the starter. On their bench, it would send 12V to the fuel pump post on the starter solenoid.
We assumed it was some kind of grounding issued but the starter turns the engine over without issue.

I brought it home, cleaned everything up and tried again. I am still getting 8 volts on the fuel pump post of the solenoid.

I confirmed the supply from the relay is 12+ volts. (I aslo jumped the relay).

Any suggestion? How can I further test?

Ayuh,.... Remove, sand, 'n clean to Shiny metal clean, the battery terminals, 'n the connections to the block, 'n starter, though the starter oughta be just done....

If that don't Fix it,...

Replace the worst lookin' of the 2 battery cables... 1 of 'em ain't carrin' the amperage needed...
probably corrosion...

 

[kaw550]

Re: 4.3 Starter not operating fuel pump

I went through every wire already. I cleaned and sanded all of them.
THe odd part the starter works everytime. I think that ruels out the wires from the battery.

I just took that starter back out and did my own bench test. I got 9 volts.
I used jumber cables off the battery.
I dont know what he connected the meter to at the shop but it has to be the solenoid. Well unless the wires had been swapped at the back of the starter at some point.

 

[Bondo]

Re: 4.3 Starter not operating fuel pump

I went through every wire already. I cleaned and sanded all of them.
THe odd part the starter works everytime. I think that ruels out the wires from the battery.

I just took that starter back out and did my own bench test. I got 9 volts.
I used jumber cables off the battery.
I dont know what he connected the meter to at the shop but it has to be the solenoid. Well unless the wires had been swapped at the back of the starter at some point.

Ayuh,... The Exciter terminal, is the inside, close to the block little 1....

The fuel pump is the little Outside terminal....

 

[kaw550]

Re: 4.3 Starter not operating fuel pump

Well it is wired correctly...
I have another place I can bring it to tomorrow.

Should I be looking at a new starter?

 

[Don S]

Re: 4.3 Starter not operating fuel pump

Before you start throwing parts at it, get your volt meter, with the black lead on ground, put the red lead on the D terminal in the picture below. Then crank the engine and see what you get Do the same thing on terminals A and C. They should all be close to the same thing. are they?

 

[kaw550]

Re: 4.3 Starter not operating fuel pump

Yesterday, I stopped by another auto electric shop. I had called the guy who said he had new starters and solenoids. He bench tested the starter and confirmed it was sending 8v to the fuel pump. He put on a new solenoid and it was up to 12v.

He couldn't believe it so be broke open the old one to see what was wrong. Everything looked fine. Nothing was missing, broken or rusted.

I will install it today.

 

[kaw550]

Re: 4.3 Starter not operating fuel pump

I spoke too soon. Same issue. Not sure how on the bench there is clearly a difference in what the solenoids are putting out.

Don, All the posts measure 9v when cranking.... is that normal?
Is the starter drawing too much power to supply the fuel pump.

The engine cranks every time. It seems like the battery is fine.

 

[Don S]

Re: 4.3 Starter not operating fuel pump

Don, All the posts measure 9v when cranking.... is that normal?
Is the starter drawing too much power to supply the fuel pump.

It's normal for the cranking voltage to be lower than normal battery voltage.
It is low voltage, but shouldn't go below 10, but that could be because the battery is weak (get it load tested) or the cables are loose or corroded. Could also be a bad starter, or even engine/drive problems.

 

[kaw550]

Re: 4.3 Starter not operating fuel pump

Okay. I am finally getting back to this. I spent the last couple of months replacing the deck and carpet.

I have cleaned the cables. All look good.
I had the battery load tested and was told it was good.

A few months back I had the solenoid on the starter replaced. When I did that it jumped from around 8v to about 9v.

I am making sure the battery is charged then i am going to try cranking the engine while the battery is jumped with my truck. That should rule out the battery.

Any other suggestions? Do I buy a starter?
It does turn over and will start fine if I prime the pump using a 12v source.