Hi guys,

I bought a new HPFP for my 2008 LNF off ZZP. I can't find any good install guides here or Google or youtube. However, it looks pretty straight forward. Looks like its bolt old one out then new one in? Just dealing with a fuel system sounds a little sketchy to me. Something something fuel under pressure something something fire.

If anyone could please link me to a how to or please give me some insight, or I'll just call up my tuner (ahem, KMO43) and buy him some more beer haha.

Thanks!

 

Cylinder 1 has to be at a certain stroke I think.

 

Mine wasn't , just unbolted it, disconnected and pulled it off

 

Ok so here are my options so far I have found. Relieve fuel pressure by taking out the fuel pump fuse and run the engine till it quits; or poke the Schrader valve and let it leak out that way... hmmm

 

Just unbolt it. When you bolt back up Gm wants you to replace the tube between the pump and the fuel rail as the flange gets crushed slightly and can leak under 2000psi +. Be careful and you will be ok. Steve

 

I've had mine off quite a few times. I don't think it mattered where the #1cyl was. Seemed to work fine taking it out/in wherever. I just put a shop towel under the pump and the fuel runs into that when you crack the lines. You can run out the pressure removing the fuel and running, but I really don't think its necessary. GM does indeed ask for the replacement of that line, but I've reused them before while waiting for new one to come in and haven't seen one leak, but its cheap insurance. The new line may or may not look like the old one, there's been some number/style changes. When you tighten the pump bolts, make sure to see saw back and forth between them to equalize the torque.

 

General rule of thumb on high pressure compression fitting you can get 1 reuse, I reused the fitting on my car and have no fuel leak. On an e47 tune commanding >2000psi for a decent chunk of the rpm range.

 

Well the install went pretty good. Wasn't as bad as I thought it would have been. Had to go down to Cambodian Tire to pick up a fuel line disconnect tool. It seemed to have solved my problem of gas fumes coming through the vents at a stop and filling the garage with gas fumes.

 

Furthermore, I got quoted by GM at $1300 to repair this. Over $800 for the part then the rest labour etc. I bought the part for about $300 and did it myself in a few hours.

 

What kind of disconnect tool did you need? That price quoted by GM was outrageous! I know they markup the part and pay the bills, but wow, 300%? And $500 for an hour job? Glad you got your hands dirty and got it in : )

 

Umm fwiw, its best to let the fuel pressure subside overnight(several hours after it has last been started/driven) TO AVOID SERIOUS INJURY. If you Crack that high pressure line open with several hundred Psi of fuel stored inside of it..... Yikes.
Remove fuel tank cap, pull fuel pump relay and crank until it won't start anymore. yes always use new high pressure fuel line. GM says to replace oring, gasket, and bolts too which is not always necessary.

There is actually a special sequence used for tightening the low pressure and high pressure components. I remember the LAST step was torque the fuel pump bolts to the head from hand tight. And always torque down LP side before HP side. Use your best judgement.

 

I don't mean to bring an old thread back to life but I would rather ask in here then create a new thread...

I will have my hpfp here on Wednesday and I'll be able to replace it thursday. Above it states that you need to make sure your cylinder 1 has to be at a specific spot? Then someone says I also need to replace the fuel lines? Some say you can just unbolt the two lines, disconnect the two hoses and replace...

When disconnecting the lines I expect some fuel to come out, will it be a lot or would a rag be fine? Do I need to get a fuel line disconnect tool? The more I am researching on how to do this, the more I am feeling confident with doing it. I also have the previous owner of the car coming to help as well as he has mechanical experience. I was quoted by a local garage here to do this for $918.00.

 

I just did this a few weeks back. Super easy. Pull your fuel pump relay and let the car stall. You can let it sit overnight if I makes you feel better, I did not. Have a towel handy for any leaking. Its not going to be anything crazy. Just some drips. There are like 3 or 4 bolts to remove the plate around the hpfp. Then you can loosen the two lines and the two bolts that mount it. Remove and replace. You can get this done in under 30 mins easily.

 

Thank you for letting me know, much appreciated. The car will be sitting until Thursday when the pumps goes in. What is the reason to pull the pump relay and wait for the car to stall?

 

No problem

It helps make sure that there is only minimal fuel in the lines and relieves the pressure in the system.

 

Looks like this thread came back to life at the right time. Started noticing a bit of a fuel smell last week when idling and at start up allot of clatter. It began starting pretty hard shortly there after on cold starts. (Similar to when you pull the battery and it starts for the first time. Kind of like it's priming itself for a few seconds.

 

Will that cause the initial start up after the new pump is installed to be a little rough? Since there won't be any fuel pressure in the lines?

 

Yes it will take some time for fuel to get into the lines, so expect it to turn over for maybe 10 seconds.

 

ZZP upgraded my shipping to overnight for free! Told them in the order notes that I really needed the part for Thursday morning.. Got the shipping confirmation email and it said overnight delivery. Thank you ZZP!!!

 

If you cycle the key on/off 4 or 5 times ( listen for the fuel pump to start/stop ) it should fill the fuel rail before you crank the engine so it will fire right up.

 

I was watching a video on YouTube on how to replace these.. What is this that he pulls out and then back in?

 

That's the roller for the hpfp. It's what the cam pushes on to drive the pump.

 

Just replaced the pump.. Very easy, even though a friend did it, I know I can do it myself next time. Haha hopefully it fixes the issue.. Feels like it's much more responsive when I hit the gas.. But maybe that could be because I have been driving my 06 LS since Monday haha. God that car is so slow!! I really hope this fixes the issue.

When I unplugged the fuse, it felt like forever for the car to stall!!

Oh and also fixed my parking light issue, with the paper clip trick in the socket. Haha. It's been a good day. Haha

 

I just did this as well.

Took me 45 minutes with the $200 replacement HPFP from ZZP. My local dealer quoted $954 to do it!!!

Overall it was pretty easy and clean. It's nice to have some power back!

 

Your local dealer is a ripoff artist