So here's a shot at my first HOW TO. Our friend Black Tara needs a new DI fuel pump. Which is mechanical driven by the intake cam. It's located on the front drivers side of the engine and it and the fuel rail usually have a foam padding over them. I removed for easier viewing + it's shiny and foam isn't! Without further ado, removing a DI fuel pump.

CAUTION: THIS IS A HIGH PRESSURE SYSTEM. PLEASE RELIEVE PRESSURE BEFORE ATTEMPTING TO REMOVE ANYTHING ASSOCIATED WITH THE PUMP!



This is a general pic of what we're removing. If you still have the factory air box, you'll probably need to unhook some of it to get it out of the way. I have ZZP charge piping but the factory tube bolts in the same place.



STEP 1: Depressurize the system. Remove the cap off the pressure relief valve. Using a small blunt object (ie: screwdriver) and a rag or two depress the needle slowly. You don't even need to fully depress it, gas will come out immediately. So cover the valve with those couple rags you grabbed earlier. It might not be necessary to remove the silver disc (filter) but the fuel line (hard line)might be in the way to remove the pump.



Step 2: You are looking under the pump from the intake side. Remove the electrical connector. There are 2x 13mm bolts that attach the pump to the cylinder head. There are 2x 17mm fuel lines that connect to it. The hard line you see here is the one that runs over from the silver disc on the intake.



Step 3: This is my first shot where you can see (for lack of a better term) Bracket "A". It's a very close up! We need that guy out of the way. There are 3x 10mm bolts holding it in place. 1 on the side of the intake and 2 on the drivers side attached to the cylinder head. The head side is generally buried under EVERYTHING so they are hard to find. The second fuel line is down there and it runs to fuel rail.



Step 4: This is almost the same shot but it's pulled back so you can see the line and bracket "A" much better. You only need to loosen the connection at the fuel rail. The line will move enough to get the pump off. Don't worry if you do take it off, it can only go on 1 way (I've tried!) You can also see the 10mm bolt holding bracket A to the intake. I drew in the ones to the head but we're heading there next.



Step 5: There's those pesky bolts! If you have your battery unhooked go ahead and unplug the large connector from your ECM it will make things much easier, also the line I'm holding is your brake booster vacuum tube. It moves quite freely. With bracket A out of the way there should be nothing stopping you from removing your pump. The only thing that might fall out is an o ring. If it doesn't, make sure it isn't stuck inside. You certainly don't need 2! And your replacement should have a new one of those (don't forget to put a little oil it.) O rings don't line to be dry!



Looks like you got the pump off, now just put it all back and you'll be good to go. Any questions or comments greatly appreciated. It was a long night at work so hopefully this comes out making sense!

This job should only take about an hour. And that include finding tools and putting them away!
Thanks
Danby

 

Nice write-up Let me add that the DI pump has also been a source of an oil leak at the front of the block, mine leaked new.

 

Great tutorial, thanks for taking the time to share your experience.

 

I can attest to it being prone to leaking. Mine had a small leak when new but thankfully the leak has all but stopped after 5 years.

Just to note. Mine came with a bracket and a foam rubber insulator that covered the DI pump. That insulator absorbed a lot of the seeping oil I had. I took the insulator off 3 years ago because it was totally saturated with oil.
I think GM used that insulator to cut down on some of the DI pump noise.

 

I'm sure you are correct about the noise, although I believe the other diesel sounds are from the injectors themselves.

 

You know, I hadn't thought about it leaking but the drivers side of my gen 2 was covered in oil. And the foam was definitely saturated. I'll keep an eye out for a leak on the new motor. If it does start to leak, I'm sure you can make a gasket to seal the pump to the head. The O ring goes inside the opening prevent it leaking through but apparently that design has some issues.

I can't have oil on my new red paint!
Thanks everyone!!

 

A gasket would work, but most likely, a good bead of RTV sealer should do the trick.

 

I resealed the HP Fuel pump, the intake sensor had the o-ring was gouged, and the cam end cap was leaking. Here is a very good write up on the complete provedure, 2.0 LNF Engine How-To: Repair LNF cylinder head oil leaks - Page 2 - Cobalt SS Network if you are interested.