Relieving HPFP Pressure

[gofaster]

I'm trying to inspect my cam followers using the PDF DIY floating around here. But I do not understand how to correctly relieve the pressure from the reading. How do I do it correctly?

Btw, I also here an air leaking sound when the car is idle. But the sound goes away when the brake pedal is pushed down. Is that normal?

[plokm]

I just unscrewed the gas cap

[gofaster]

^Thanks plokm,

I will do that. But the PDF also states to remove fuses. Is that required?

[plokm]

I would highly recommend you to remove the fuel pump fuse or the negative terminal off the battery. First time I checked my cam follower I didn't remove it and made the mistake of opening the driver door after i removed the hpfp off the engine and gas sprayed all over the engine bay.

[jimrobbington]

Yes, You must remove the fuse. I can't remember which one. Pull the fuse while the car is running so that the HPFP runs out of pressure. That shit is not safe at all when it is pressurized.

[palestar]

You need to remove the connector off the high-flow line on he HFPF, let the car idle for 10 seconds. Remove the fuse for the fuel pump which will stop the prime that happens when you open the door. \

Just did my cam follower and did the above and just had a few small drips of fuel

[A4 Effort]

Pulling the fuse is recommended. You can also relieve the pressure through the schrader valve on the hpfp - just be sure to put a rag in front of it to catch any fuel spray

[jimrobbington]

BAM! Ask and you shall receive. I tracked it down for you in the official cam follower thread.

You'll have to take out fuse 28 in the fuse panel. Then run the car until it dies. I cranked a few extra times just for fun. Some gas will leak when you take off the fittings, but I had no spray whatsoever. VERY important though that you do this, as it does build 1500-1600psi. It's not a step you just forget to do...

Also, like stated above, some HPFP have a pressure release valve, but some don't. Just pull the fuse to be safe.

[billyhoyle]

You need to remove the connector off the high-flow line on he HFPF, let the car idle for 10 seconds. Remove the fuse for the fuel pump which will stop the prime that happens when you open the door. \

Just did my cam follower and did the above and just had a few small drips of fuel

^^ This. You can pull the fuse and disconnect the connector (the one on top of the fuel pump) at the same time. You don't have to do one first.

[gofaster]

Thanks you guys. Extremely helpful answers.

[XCELR8]

Only think thats keeping me from doing this myself is all the talk in the .pdf about "110 bar pressure system to a 50 bar" yadda yadda "regulate fuel pressure" etc etc. If it's as simple as pulling a fuse and letting the car idle till it dies I'll do the repair myself.

[jimrobbington]

Only think thats keeping me from doing this myself is all the talk in the .pdf about "110 bar pressure system to a 50 bar" yadda yadda "regulate fuel pressure" etc etc. If it's as simple as pulling a fuse and letting the car idle till it dies I'll do the repair myself.

That's exactly how you do it. Very simple. For such an expensive, important, powerful little pump, it was one of the easiest things I have ever done myself to this car. Ten times easier than the DV.

[XCELR8]

Ok cool cause I'm getting quoted $150+ to change it out, even with my own parts.

[jimrobbington]

Ok cool cause I'm getting quoted $150+ to change it out, even with my own parts.

That's an hour and a half labor! It might take you an hour to do it your first time at the most.

[XCELR8]

Great! Not paying for that to be done makes the $690 for the fully loaded APR tune next week a bit easier to swallow.

[gofaster]

I'm with you xcelr8, the PDF makes that step seem scary about the bars...

But to clarify, do I remove the fuse and line after I turn on the ignition. And is it safe to just let the car die like that?

Thanks guys.

[shiro1745]

I'm with you xcelr8, the PDF makes that step seem scary about the bars...

But to clarify, do I remove the fuse and line after I turn on the ignition. And is it safe to just let the car die like that?

Thanks guys.

This is a good question. It's not really clear in the DIY when you have to remove the connector 2 from the HPFP and fuse 28. Is it while the car is running? Or you remove the connector first and then turn the engine on?

I just checked my cam follower the other day and had the car running when I removed the connector from the HPFP and fuse 28, then turned off the engine. I have the release valve on the pump and after I turned the engine off I pushed it in with a wire, it's just a bit of gas coming out, of course if you do the things mentioned before. I only used a blue shop towel and it was enough. After put everything back my check engine light came on. I turned the engine on and off a few times and it disappeared. So I'm not sure if I did it in the right sequence or if that's normal.

And by the way ... for those who want to see a dead cam follower
http://www.audizine.com/forum/showth...DATE-NEW-PICS-!!!

[jimrobbington]

Pull the fuse while the car is idling. You could also pull the fuse, then start the car, but if the car didn't start, it might not releive the pressure. Just make sure the car dies from lack of fuel.