Fuel Pump: S-10; January 2015

I replaced the fuel pump on my 2000 Chevy S-10 with a 4.3L back in 2015. Now, I was a bit aggravated with this fuel pump because I replaced it a year or two prior to this. Being a Delphi brand fuel pump, I was expecting a long lasting quality part. If it was a Carter fuel pump then I would give it praise for lasting well past its life expectancy. ;-)

Note: I would never put a Carter fuel pump in any of my vehicles. I have seen them fail after 6 months to year when I worked in a parts department.

Diagnosis

Prognosis is that the fuel pump is bad because it would not kick on when the temperature dropped down into the cold range (I don't recall but we can speculate below 35 degrees Fahrenheit). I knew the fuel pump wasn't kicking on because I could hear it (or lack thereof) not kicking on. The fuel pump on this truck is fairly loud so cycling the key with the driver's door open will allow any person with normal hearing to hear it. Sometimes it is even audible with the door closed.

Anyway, long story short, my prognosis was wrong: the fuel pump was good. The problem was that the female terminal pins of the fuse box for the fuel pump relay were spread too far apart and not making a great connection. Over the years, I must have been sticking things down in the terminals that were too wide and shouldn't have been used such as a PC2000 (paper clip) when doing tests. Oh well, I learned my lesson and got a free fuel pump out of the deal since the Delphi was still under warranty.

How do I know it was the fuel pump relay terminal pins? Well, because right after I replaced the fuel pump and before I put the bed back on it, the truck did the exact same thing it had been doing in which the fuel pump would not kick on when the key was cycled or you tried to start the truck. It took a bit of time to figure it out but I eventually got there.

Repair

As previously stated above, the problem with the fuel pump not turning on when the weather got cold was due to the terminal pins of the fuse box not making a great connection with the Fuel Pump Relay located in the Underhood Fuse Block (fuse box). Therefore, the fix is to either replace the Underhood Fuse Block or decrease the spread of the female terminals. I chose the latter because I didn't want to buy a new fuse box especially when mine was in great shape except for the current predicament.

The procedure was fairly simple:

1. Disconnect the power source(s) (the battery for this beast).

   1. I usually just disconnect the negative battery cable.

2. Remove the cover to the Underhood Fuse Block.

3. Disconnect the positive cable attached to fuse box.

4. Remove the Fuel Pump Relay and any surrounding relays and/or fuses that are in the way.

5. Drill small holes next to terminals where Fuel Pump Relay mounts.

6. Use a device such as an awl to push the terminals back together.

Now, I did try to take the fuse box apart and get to the terminals that way but was unsuccessful. I was able to separate the fuse box in two but there was still a piece covering the area I needed and removing such piece didn't seem possible without permanently breaking the apparatus in some form or fashion, so I scrubbed that idea and proceeded with drilling holes. Unfortunately, I don't remember the size of the drill bit that I used but using good judgement should suffice. Also, it is best to fill the holes back in after pressing the terminals back towards respective rectangular hole.

Bed Liner

In case anyone is thinking that cutting a hole in the bed looks tacky (I would agree), I have a drop-in bed liner on my S-10. It's a bit slippery and allows certain things to slide around in the bed but it works. I can quite literally pull the bed liner out in under 5 minutes. Once the three screws at the back (tailgate end) are removed, lift up in the middle from the back-end and the liner sort of folds-in on itself.