High and Low Fuel Pressure pump

[subtl3dilig3nc3]

Hi all, I am sure this has been asked so many times before but given how newbie I am I needed to started this thread just to find an actual thread about this.

So My CEL came on, along with misfiring. Did a diagnosis, and its the High and Low fuel Pressure pump, according to the shop. I opted to wait another week before getting it actually fix since I had to fix a cracked coolant reservoir first and didn't wanted to spend as much at the same time.

Shop quoted me $199 for parts and 1.5 hours job. Is that fair?

One more thing I just started googling this, how big of a possibility is there that my cam shaft is also needed to be replaced?

And how expensive is cam shaft?

I bought the car used. 120K on it.

Thanks all!

[Audibot]

Oh boy... where to start?

1. What codes did you specifically have? Any chance you have VCDS (or vagcom as it is colloquially known)? If not, try a post in the regional forum to see if anyone from your area can scan it for you.

2. There are two different low and high pressure fuel pumps. The lpfp sits in the tank, as expected. The hpfp sits on the engine and is driven by the camshaft. The hpfp has a "thrust sensor" on it, which is on the low pressure side. If you look at the pump on the engine from the front, it should be a connector threaded into it pointing back at you.

Often times low fuel pressure codes for the lpfp are because the fuel filter needs to be changed, and cannot supply the required flow and pressure to the hpfp. Over time, of course, this can burn out the fuel pump, but you may be able to get away with replacing the fuel filter. Easy job if you have ramps.

4. $199 and 1.5 hours for which job? Coolant reservoir you could do yourself by buying one online or off a member here. Easy job to do when the car is cold. But a new hpfp is >$200 (probably excluding the cam follower), a lpfp is probably not far off from that. So what is that quote for? I feel like you're being scammed...

5. It's non-zero that your camshaft needs to be replaced, but I think the likelihood is small at this point. Since you're in that area, you might as well have the cam follower replaced (if you truly do not need a new hpfp), which is not a hard job and there are DIYs on here. Or, if a competent shop did it, should take 1 hr or less. If you needed a new hpfp, you would naturally have this replaced.

For your misfires, No fuel=no burn=misfiring. Could also be plugs or coil packs.

[Okedokey]

I have a spare OEM HPFP for sale if required.

[Charles.waite]

High AND low pump? I find that hard to believe...

The thing is too, both the HPFP and LPFP ALONE cost over $200... Parts alone for DIY'ing both would be over $400. That obviosuly wouldn't include labor. WTF is this shop charging you for then? Used parts? doing nothing? hard to tell...

Since you're local, what shop in Seattle is this?

[klrider44]

I believe I am having a similar issue. I did a quick scan with a generic reader and I got P0089 (fuel pressure regulator) and P0328 (knock sensor bank 1). I did just purchase a vag com cable though so I can dive in deeper. My lpfp, fuel filter, and cam follower were replaced about 12,000 miles ago. New coil packs about 2,000 miles ago. The CEL has since gone off, but I will get hesitation occasionally at WOT. It is to my understanding that you can log duty cycle of the lpfp to see if is operating within spec. Can you do the same for the hpfp? If so how do I go about doing these tests,


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[Cobra351]

I believe I am having a similar issue. I did a quick scan with a generic reader and I got P0089 (fuel pressure regulator) and P0328 (knock sensor bank 1). I did just purchase a vag com cable though so I can dive in deeper. My lpfp, fuel filter, and cam follower were replaced about 12,000 miles ago. New coil packs about 2,000 miles ago. The CEL has since gone off, but I will get hesitation occasionally at WOT. It is to my understanding that you can log duty cycle of the lpfp to see if is operating within spec. Can you do the same for the hpfp? If so how do I go about doing these tests,


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I also was asking this, as I was having some starting issues(mostly after filling up gas), sometimes. I've found that when you go into Measuring Blocks > Group 106 shows the LPFP duty cycle(iirc). I was not able to find the cycle for the HPFP.

[Brillo]

LPFP is driven by an electric motor so its duty cycle can be logged. The HPFP is a mechanical pump so it has a continuous duty cycle based on engine rpm. If your cam follower is in good condition, the cam lobes for the pump are not worn down, and you cannot smell gas in your engine oil (piston seals in the HPFP are intact) most likely your HPFP is OK. There are two electrical connections that go to the HPFP. One is the pressure sensor and the other is a solenoid that controls a ball valve between the low pressure side of the fuel delivery system which controls ingress of fuel into the HPFP. Either can malfunction. The net result will be low pressure at the fuel rail which can be logged. If memory serves me the rail pressure should be about 115 bar.

[subtl3dilig3nc3]

High AND low pump? I find that hard to believe...

The thing is too, both the HPFP and LPFP ALONE cost over $200... Parts alone for DIY'ing both would be over $400. That obviosuly wouldn't include labor. WTF is this shop charging you for then? Used parts? doing nothing? hard to tell...

Since you're local, what shop in Seattle is this?

It's Stones German Garage Ballard

Basically the quote said this

"High and Low Fuel Pressure Sensors.. 199.00"

Just got out of the Shop btw it is done, the car is running smoothly so far. But that plus oil change turns out to be $500.

[subtl3dilig3nc3]

I believe I am having a similar issue. I did a quick scan with a generic reader and I got P0089 (fuel pressure regulator) and P0328 (knock sensor bank 1). I did just purchase a vag com cable though so I can dive in deeper. My lpfp, fuel filter, and cam follower were replaced about 12,000 miles ago. New coil packs about 2,000 miles ago. The CEL has since gone off, but I will get hesitation occasionally at WOT. It is to my understanding that you can log duty cycle of the lpfp to see if is operating within spec. Can you do the same for the hpfp? If so how do I go about doing these tests,


Sent from my iPhone using Audizine

Mine was doing the same thing. With check engine light on and off, it started since before Thanksgiving, but then since last week the check engine stayed on, and the misfiring is getting more often only on the freeway about 2000rpm on 6th Gear. Shop charge me about $400 for fix, and I decided to get it done.

- - - Updated - - -

LPFP is driven by an electric motor so its duty cycle can be logged. The HPFP is a mechanical pump so it has a continuous duty cycle based on engine rpm. If your cam follower is in good condition, the cam lobes for the pump are not worn down, and you cannot smell gas in your engine oil (piston seals in the HPFP are intact) most likely your HPFP is OK. There are two electrical connections that go to the HPFP. One is the pressure sensor and the other is a solenoid that controls a ball valve between the low pressure side of the fuel delivery system which controls ingress of fuel into the HPFP. Either can malfunction. The net result will be low pressure at the fuel rail which can be logged. If memory serves me the rail pressure should be about 115 bar.

Thank you, and yes the Cam lobes seems doing ok. The shop said I don't need to worry about that for now.

[subtl3dilig3nc3]

Oh boy... where to start?

1. What codes did you specifically have? Any chance you have VCDS (or vagcom as it is colloquially known)? If not, try a post in the regional forum to see if anyone from your area can scan it for you.

2. There are two different low and high pressure fuel pumps. The lpfp sits in the tank, as expected. The hpfp sits on the engine and is driven by the camshaft. The hpfp has a "thrust sensor" on it, which is on the low pressure side. If you look at the pump on the engine from the front, it should be a connector threaded into it pointing back at you.

Often times low fuel pressure codes for the lpfp are because the fuel filter needs to be changed, and cannot supply the required flow and pressure to the hpfp. Over time, of course, this can burn out the fuel pump, but you may be able to get away with replacing the fuel filter. Easy job if you have ramps.

4. $199 and 1.5 hours for which job? Coolant reservoir you could do yourself by buying one online or off a member here. Easy job to do when the car is cold. But a new hpfp is >$200 (probably excluding the cam follower), a lpfp is probably not far off from that. So what is that quote for? I feel like you're being scammed...

5. It's non-zero that your camshaft needs to be replaced, but I think the likelihood is small at this point. Since you're in that area, you might as well have the cam follower replaced (if you truly do not need a new hpfp), which is not a hard job and there are DIYs on here. Or, if a competent shop did it, should take 1 hr or less. If you needed a new hpfp, you would naturally have this replaced.

For your misfires, No fuel=no burn=misfiring. Could also be plugs or coil packs.

199 for 1.5 for the High and Low fuel pressure.

Coolant was already done. But it was high priced it was $201, new coolant and cap without labor. I am such a newbie at this and wanted to build a good relationship with the shop so I thought I'd sacrificed that.

Btw shop said no need to replaced the cam follower, that I am good on that. Kind of scary to think of that can happen anytime tho.

[Okedokey]

Sensors are not the pumps and they're very very easy to replace. IF you're going down that route do it yourself.

[klrider44]

Is there anyway I can test the sensors via vagcom?


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[Audibot]

Sensors are not the pumps and they're very very easy to replace. IF you're going down that route do it yourself.

^^What he said! Most of this sounds DIY, and either the shop is trying to swindle you or they don't know what they are doing.

Is there anyway I can test the sensors via vagcom?


Sent from my iPhone using Audizine

Yes, you can call up the measuring blocks on the engine when it's running, IIRC.

[klrider44]

I am very new to vag com. Would you happen to know what blocks and what values are within spec?


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[Audibot]

Ross-tech is your friend! http://wiki.ross-tech.com/wiki/index...B/BPJ/BPY/BWA)

I recall at idle my hpfp (upgraded) would sit around 50 bar and highest I recalled getting it up to was ~125 bar. At idle, my lpfp would be between 5.2 and 5.6 bar. Highest I recall it being during driving was just over 6 bar, but if you go WOT, it will decrease. Below ~4.8 bar, it throws a code I think.

From Ross-tech link above:

Checking Fuel Pressure
Prerequisites:
Ignition ON
Engine ON (Idle)
System voltage at least 11.0 V.
Coolant Temperature at least 80 °C

[Select]
[01 - Engine]
[Meas. Blocks - 08]
Group 103
[Go!]
Field 1: Fuel Pressure (Low), Specification: 2800...7200 mbar
Field 2: Fuel Pump Adaptation, Specification: -1000...+1000 %
Note:

Timing chain driven engines such as the CCTA, CBFA and CCTA were phased in during model year 2008. Those engines do not use a G410 (Low) Fuel Pressure Sensor so Measuring Blocks group 103 is not applicable.

Group 106
[Go!]
Field 2: Fuel Rail,Pressure (actual): 55% or below is normal at idle
55% to 60% is a gray area, it may be okay, but may indicate a problem
Above 60% implies there is a failure or restriction
Causes of low pressure can include kinks or restrictions in fuel lines
Fuel filter issues including restricted/clogged or incorrect part number
Failing lift pump in fuel tank. We have seen numerous cases of sub-standard quality "factory" replacements in "factory boxes" that were obtained from aftermarket sources and are not sourced from official dealers. This led to troubleshooting problems that were solved by installing correct factory parts. We encourage customers to only install lift pump and fuel filter sourced directly from a VW/Audi dealer.

Group 140
[Go!]
Field 3: Fuel Rail Pressure (High), Specification: 25.0...110.0 bar
Increase the Engine Speed while checking this value, the Pressure has to rise with the Engine Speed.
Group 230
[Go!]
Field 1: Specified Fuel Rail Pressure (High)
Field 2: Actual Fuel Rail Pressure (High), Specification: 25.0...110.0 bar
Field 3: Deviation between specified and actual fuel pressure, Specification: max. 5.0 bar

[Cobra351]

Ross-tech is your friend! http://wiki.ross-tech.com/wiki/index...B/BPJ/BPY/BWA)

I recall at idle my hpfp (upgraded) would sit around 50 bar and highest I recalled getting it up to was ~125 bar. At idle, my lpfp would be between 5.2 and 5.6 bar. Highest I recall it being during driving was just over 6 bar, but if you go WOT, it will decrease. Below ~4.8 bar, it throws a code I think.

From Ross-tech link above:

Thank you very much sir! This is extremely helpful.