High Pressure Fuel Pump Issue Plz Help

[sam_stoelting]

So I have a 2006 GTI and just bought the car thinking it was going to be an easy fix. I have the code P2293 stored for fuel pressure and started guessing and replacing parts. I've replaced the low-pressure fuel pump, the fuel filter/regulator, fuel lines, and the high-pressure fuel pump, and no progress. the car is in limp mode which I've read is pretty common but I still cannot resolve the issue. I went to a friend and with a good program to read the fuel pressure. The low-pressure fuel pump is solid with its values but the problem is with the HPFP. When under load the pump cannot produce the required 50 psi of pressure.

This is where I need help, Mechanics have recommended upgrading the fuel pump to an aftermarket one or upgrading the fuel pump internals and I just want someone to verify that before I spend $300+ on an upgrade. Also if I do that, would I need to tune my car. Thanks for the help!

 

[sam_stoelting]

Also camshaft if good And new cam follower

 

[ROH ECHT]

Other things it may have wrong are:
Leaking/stuck open injectors or leaking FPRV. Have you had someone check if the rail pressure holds and rises when the engine is hot and shut off? Typically, the rail pressure will rise a bit from the heat of the engine. So one needs to look at the rail pressure data and sit and watch what it does. If the pressure drops quickly when shut off...then the injectors or the FPRV are leaking and losing rail fuel back into the low pressure delivery line to the HPFP. Has the rail pressure been viewed with a gauge to see if the "G247-pressure sensor" is reporting accurately?

If the injectors and FPRV hold pressure and the pressure sensor and tri-lobe are OK...upgrading the HPFP internals isn't going to fix the fact that it isn't producing proper pressure as it should. You wouldn't need to tune for it. The HPFP internals upgrade alone will simply pump more. Tuning for it would put you in the place you are now. Because tuning would set a higher pressure target that it could not make. I suspect the tri-lobe on the intake cam. But all else must be ruled out first. What people do is sell them to avoid the $2k repair cost by a shop for a new intake cam and HPFP. I once had a guy come by to have me check out his 2.0t FSI. I removed the HPFP and the cam follower was worn through, the tri-lobe was worn and slightly grooved, and the end of the HPFP piston was worn off. I added a slightly used cam follower so he could drive it home and do less wear and told him what he needed to do quickly to repair it all. A week later I saw he had posted it for sale and saying the common problem of the cam follower was looked at and all is OK. That's what some people are like. Just because the tri-lobe looks good...doesn't mean it isn't worn at its peaks from previous follower failures. All they needed was a used HPFP and follower and a for sale sign or listing.

 

[sam_stoelting]

Other things it may have wrong are:

Leaking/stuck open injectors or leaking FPRV. Have you had someone check if the rail pressure holds and rises when the engine is hot and shut off? Typically, the rail pressure will rise a bit from the heat of the engine. So one needs to look at the rail pressure data and sit and watch what it does. If the pressure drops quickly when shut off...then the injectors or the FPRV are leaking and losing rail fuel back into the low pressure delivery line to the HPFP. Has the rail pressure been viewed with a gauge to see if the "G247-pressure sensor" is reporting accurately?

fuel system.png



If the injectors and FPRV hold pressure and the pressure sensor and tri-lobe are OK...upgrading the HPFP internals isn't going to fix the fact that it isn't producing proper pressure as it should. You wouldn't need to tune for it. The HPFP internals upgrade alone will simply pump more. Tuning for it would put you in the place you are now. Because tuning would set a higher pressure target that it could not make. I suspect the tri-lobe on the intake cam. But all else must be ruled out first. What people do is sell them to avoid the $2k repair cost by a shop for a new intake cam and HPFP. I once had a guy come by to have me check out his 2.0t FSI. I removed the HPFP and the cam follower was worn through, the tri-lobe was worn and slightly grooved, and the end of the HPFP piston was worn off. I added a slightly used cam follower so he could drive it home and do less wear and told him what he needed to do quickly to repair it all. A week later I saw he had posted it for sale and saying the common problem of the cam follower was looked at and all is OK. That's what some people are like. Just because the tri-lobe looks good...doesn't mean it isn't worn at its peaks from previous follower failures. All they needed was a used HPFP and follower and a for sale sign or listing.

I have not tested the rail pressure yet so I will do that. As for the tri-lobe, how do you determine if it is worn or not because when I took a look at mine it had some surface marks but it looked like nothing significant enough to cause a problem.

 

[ROH ECHT]

The specs aren't published...to my knowledge. I have seen, some time ago, where someone measured and compared new to original....just not sure where that is posted.

I would put set aside the likelyhood of it being due to the intake cam until rail pressure containment by the injectors and FPRV...confirming they are OK. The G247 high pressure sensor also needs to be OK.

 

[sam_stoelting]

Okay I will run those tests soon. Also I have a code "P0420 Catalyst System Efficiency Below Threshold Bank 1". Does that help pin pointing anything

 

[ROH ECHT]

When did the P0420 code appear? Just now or did it accompany the P2293?
You need to address the P0420 first before moving on with the P2293.

 

[sam_stoelting]

It appeared while trying to diognose the fuel pressure not from the start. I was just wondering because when I looked up the probable causes it said it could be a faulty or leaky injector

 

[sam_stoelting]

Update:
I proceeded with new injectors as well as a HPFP upgrade. PROBLEM RESOLVED! The car is out of limp mode and turbo spools good
BUT there are a few other codes still in effect and I will get back tomorrow with the codes received.