New HPFP

[Rob.]

After my Stage 2 map, the R-Tech guys pointed out that my HPFP was struggling. Now it's a couple of weeks down the line, the car feels like it's lost all power above 3000 RPM even with my right foot planted (though it's intermittent, and occasionally will come on full boost at random)

Do you guys know what a new HPFP would cost from the dealer (or elsewhere)?

I know about the aftermarket options, I'm just not sure I can warrant spending £400+ :(

[Dan_FR]

Struggling as in failing, or holding you back? The HPFP is a limiting factor at stage 2.... Get it checked and verified before spending out. To check HPFP log block 230 (i think it's 230) with VCDS under full load and check the actual pressure stays with the specified pressure (within a few bar)

Have you monitored boost levels to see if it's holding the same amount of boost?

[GrayMK5GTI]

Loads of used HPFPs on eBay for less than £200 last time I looked.

A used APR pump can be had for £350- although not many about. .

[Rob.]

I did some VCDS logging last night, but I missed a few check boxes so will try again later. The car drives fine (or as good as) at low revs, it can barely climb above 3500RPM.

VCDS did show an error for low fuel pressure (and the CEL light came back on briefly, which I've heard can be related?)

Noticed there's a few stock pumps for £100 on eBay, so might have to give that a go, for now at least.

[Rob.]

One thing...my current HPFP has the banjo bolt, so I'm assuming I need to make sure I get the correct revision to match mine?

[Rob.]

This is doing my head right in now 

Bought a used pump from eBay. Swapped all the fittings etc, had it on and running in half an hour.

Went for a test drive, let her warm up, then gave it some full throttle off the motorway slip. Went through all the gears as good as new...then literally 3 miles later, the same problem appears again.

Left it for an hour at the gym, on the drive home gave it some beans in 2nd and 3rd and it was back to normal. Round a roundabout...no power above 3000RPM.

I did some VCDS logging before the change, so will post up the graphs when I get some time to look at the data.

I'm scared of shelling out £150+ for a new OEM pump in case the map is somehow killing them?

[edd30]

Rob, did your logging show the HPFP not keeping up with requested flow before you changed it ? Is the new one showing the same?
Have you spoken to RTech?

[bacillus]

Please post the logs!
Do you have any stored fault codes as my gut feeling it's either your low fuel pressure sensor (old revision ones are prone to go bad) or your lpfp can't maintain sufficient output pressure...

[howie1987]

Could try the autotech internals? Made a big different when i went stage2+

[Rob.]

Thanks for the suggestions guys :)

Right, this log is with the old pump.

Error code as below:

000135 - Fuel Rail/System Pressure
               P0087 - 002 - Too Low - MIL ON
             Freeze Frame:
                    Fault Status: 11100010
                    Fault Priority: 0
                    Fault Frequency: 17
                    Reset counter: 255
                    Mileage: 128897 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 17:55:42

             Freeze Frame:
                    RPM: 3596 /min
                    Load: 7.1 %
                    Speed: 148.0 km/h
                    Temperature: 83.0∞C
                    Temperature: 15.0∞C
                    Absolute Pres.: 980.0 mbar
                    Voltage: 14.351 V

So logs from VCDS. Rail pressure specified vs actual...looks like it's keeping up, despite the judder. Think this is what R-Tech meant when they said it needed replacing



Then Boost specified vs actual. Foot flat to the floor, shifting up through the gears. You can see the engine speed tapering off as it reaches 3500RPM (I think I downshifted to try and get some life out of it, hence the 4500RPM spike)

I don't get this: why is the actual always a lot higher than specified? Looks dodgy.



I'm gonna swap the Rev D DV out for a Rev G on R-Techs advice.

[flashp]

Just give it back to R-Tech to straighten out.

I've not used them myself, but I'm surprised you got the car back at stage 2 with the advice that your pump may not keep up without it being resolved. I should have thought (unless it was your choice) that it was a prerequisite for your chosen tuning package. Stage 2 starts to require certain pieces of hardware and this where you run into certain opinions about what is and what isn't required. Get it right and your car will runs as hard as you like for as long as you like. If you leave the wrong hardware in place you can end up on a knife edge where depending on component tolerance & wear you may or may not get away with it.

Not saying anyone got it wrong, just get it back to the right people to fix. You'll enjoy your car sooner and protect your investment. 

[GrayMK5GTI]

It sounds like when you had it mapped it was working but not as well as it should, Niki would have de-tuned it slightly to take that into account. Sounds like over the last 2 weeks it's deteriorated further and that's why the fuel cuts have appeared 2 weeks after mapping but the car drove fine for the first 2 weeks.

As I said further up my post, there are loads of HPFPs on eBay and thankfully it's an easy (although not cheap) fix 

I disagree with @flashp as de-tuning it isn't the solution here as the HPFP is on a downward spiral, de-tuning will fix it for a few weeks before it just deteriorates to the point it starts to fail again.

Just drive gently until it's fixed 

[flashp]

It sounds like when you had it mapped it was working but not as well as it should, Niki would have de-tuned it slightly to take that into account. Sounds like over the last 2 weeks it's deteriorated further and that's why the fuel cuts have appeared 2 weeks after mapping but the car drove fine for the first 2 weeks.

As I said further up my post, there are loads of HPFPs on eBay and thankfully it's an easy (although not cheap) fix 

I disagree with @flashp as de-tuning it isn't the solution here as the HPFP is on a downward spiral, de-tuning will fix it for a few weeks before it just deteriorates to the point it starts to fail again.

Just drive gently until it's fixed 

I haven't suggested it be de-tuned.

[Rob.]

It sounds like when you had it mapped it was working but not as well as it should, Niki would have de-tuned it slightly to take that into account. Sounds like over the last 2 weeks it's deteriorated further and that's why the fuel cuts have appeared 2 weeks after mapping but the car drove fine for the first 2 weeks.

As I said further up my post, there are loads of HPFPs on eBay and thankfully it's an easy (although not cheap) fix 

I disagree with @flashp as de-tuning it isn't the solution here as the HPFP is on a downward spiral, de-tuning will fix it for a few weeks before it just deteriorates to the point it starts to fail again.

Just drive gently until it's fixed 

Obviously the disclaimer is that remaps can highlight weaknesses in other areas...I'm fine with all that :) But I really want to find out what it is so I can fix it. Niki did say the current pump wanted replacing, and that he was working around it.

So I've replaced the fuel pump with a newer revision (think it's a H, up from an F) but the same problem appeared within a few minutes...so unless the remap is actually killing the fuel pumps, I figure it must be something else causing the loss of power?

The actual fuel pressures on my graph aren't falling way short (other than the "Actual" wavering either side of the "Requested" a bit)

Stage 2 doesn't require an uprated pump (though it's obviously beneficial)

Could a leaking DV cause this much of an obvious issue?

[Rob.]

So I'm still getting an intermittent loss of power with the changed (albeit still used) pump.

This is the Actual vs Specified for the rail pressures...look pretty similar to the old pump (maybe a bit less spikey?)



Even though the car is logging a fault, could it be something else that's causing the power loss?

I'm still on the Rev D DV. Surely that couldn't make this much of an issue...could it?