a harsh lesson

[E30Dom]

How does the TSI engine work with it's vacuum pump to avoid this then?

[GrayMK5GTI]

How does the TSI engine work with it's vacuum pump to avoid this then?

It doesn't as far as I know.

It uses a roller follower (like a wheel) that rolls over the cam rather than slide over it like the TFSI one does.

IIRC someone made a roller follower for the TFSI but was £MEGA so cheaper to keep replacing your follower 

[ARV_90]

Please correct me if I'm wrong but from what i have read the 3 main causes for excessive wear/ failures on the follower are 
A revision 'a' cam that is worn where the uneven surface will literally eat away at the follower.
Uprated HPFP that put more pressure on the cam and follower
High revs which put more pressure on the cam and follower

Correct on all 3... well maybe the first 2 unless the rev limiter has been raised then 3

As an engine builder for 7 years this is my take on the fueling issues and fuel pump wear.

A worn cam lobe will give you less "stroke" to start with and putting a new follower against the worn lobe will not last as the surface hardness has gone from the lobe and will eat the new follower very quickly. I think some of the fueling issues on mapped engines will show up when the stroke of the cam is starting to diminish resulting in less fuel delivery, So the first port of call is to fit a HPFP this puts more force on the already worn surfaces and will in the end wipe the lot out just has the OP has found out.
I'm afraid if your follower has worn then the lobe is to... Eventually a new cam shaft and follower will be needed to be fitted at the same time.... The roller follower kit looks like it would be the way to go... very nice.
We were always told it is not good practice to put a new follower against an old cam shaft...  Well that's my take on it anyway 

[camfollower]

Please correct me if I'm wrong but from what i have read the 3 main causes for excessive wear/ failures on the follower are 
A revision 'a' cam that is worn where the uneven surface will literally eat away at the follower.
Uprated HPFP that put more pressure on the cam and follower
High revs which put more pressure on the cam and follower

Correct on all 3... well maybe the first 2 unless the rev limiter has been raised then 3

As an engine builder for 7 years this is my take on the fueling issues and fuel pump ware.

A worn cam lobe will give you less "stroke" to start with and putting a new follower against the worn lobe will not last as the surface hardness has gone from the lobe and will eat the new follower very quickly. I think some of the fueling issues on mapped engines will show up when the stroke of the cam is starting to diminish resulting in less fuel delivery, So the first port of call is to fit a HPFP this puts more force on the already worn surfaces and will in the end wipe the lot out just has the OP has found out.
I'm afraid if your follower has worn then the lobe is to... Eventually a new cam shaft and follower will be needed to be fitted at the same time.... The roller follower kit looks like it would be the way to go... very nice.
We were always told it is not good practice to put a new follower against an old cam shaft...  Well that's my take on it anyway 

Good post.  I think it's worth noting that in an ideal situation it would be great to replace cam and cam follower at the same time, but simple economics would dictate that for the vast majority of people this simply isn't going to happen - and replacing the cam follower regularly is still the most cost effective way of getting the most out of the cam and engine.

.
Broader question: Have there been any failures on mapped cars with standard fuel pumps and Rev.B cams that anyone knows about?
 

[robdf2]

i guarantee that if you went to your local main dealer and asked them to check the cam follower for wear they would look at you as if you were talking marshon !

i asked my dealer for a price to check it , said he never heard of that part before then came back with a price of £150 !
lol lol

[Jaywoo-GTI]

Please correct me if I'm wrong but from what i have read the 3 main causes for excessive wear/ failures on the follower are 
A revision 'a' cam that is worn where the uneven surface will literally eat away at the follower.
Uprated HPFP that put more pressure on the cam and follower
High revs which put more pressure on the cam and follower

Correct on all 3... well maybe the first 2 unless the rev limiter has been raised then 3

As an engine builder for 7 years this is my take on the fueling issues and fuel pump ware.

A worn cam lobe will give you less "stroke" to start with and putting a new follower against the worn lobe will not last as the surface hardness has gone from the lobe and will eat the new follower very quickly. I think some of the fueling issues on mapped engines will show up when the stroke of the cam is starting to diminish resulting in less fuel delivery, So the first port of call is to fit a HPFP this puts more force on the already worn surfaces and will in the end wipe the lot out just has the OP has found out.
I'm afraid if your follower has worn then the lobe is to... Eventually a new cam shaft and follower will be needed to be fitted at the same time.... The roller follower kit looks like it would be the way to go... very nice.
We were always told it is not good practice to put a new follower against an old cam shaft...  Well that's my take on it anyway 

Great info ARV_90,

I was more referring to high rev from track-days and such where the engines are really put to there limits and a lot of 2.0tfsi owners have spoke to changed to follower after each track-day.

[ARV_90]

Please correct me if I'm wrong but from what i have read the 3 main causes for excessive wear/ failures on the follower are  
A revision 'a' cam that is worn where the uneven surface will literally eat away at the follower.
Uprated HPFP that put more pressure on the cam and follower
High revs which put more pressure on the cam and follower

Correct on all 3... well maybe the first 2 unless the rev limiter has been raised then 3

As an engine builder for 7 years this is my take on the fueling issues and fuel pump ware.

A worn cam lobe will give you less "stroke" to start with and putting a new follower against the worn lobe will not last as the surface hardness has gone from the lobe and will eat the new follower very quickly. I think some of the fueling issues on mapped engines will show up when the stroke of the cam is starting to diminish resulting in less fuel delivery, So the first port of call is to fit a HPFP this puts more force on the already worn surfaces and will in the end wipe the lot out just has the OP has found out.
I'm afraid if your follower has worn then the lobe is to... Eventually a new cam shaft and follower will be needed to be fitted at the same time.... The roller follower kit looks like it would be the way to go... very nice.
We were always told it is not good practice to put a new follower against an old cam shaft...  Well that's my take on it anyway  

Great info ARV_90,

I was more referring to high rev from track-days and such where the engines are really put to there limits and a lot of 2.0tfsi owners have spoke to changed to follower after each track-day.

Totally agree with you on the economics side of things fellas... probably do the same myself as the cost of replacing both cam and follower would be rather expensive. Come to think about it I have warranty from VW with mine .... so if it does fail they will be having it back. 40k and counting so we shall see.

Get what you mean on the track day  

I wont go down the route of fitting a new follower just for the sake of it as the new follower will not have the same bedded in contact area and would possibly make things worse.

I'm not to familiar with the revisions of cam shafts but if there are revisions it shows that the load on the lobe contact area was obviously not up to it... and would probably be a wider on any revisions, At a guess the earlier cams with a narrower lobe wont like having a HPFP on as its just to much surface load for the cam.

[GrayMK5GTI]

Just to clarify, its actually LOAD rather than high revs - you can rev a car on light throttle which will not require a lot of fuel pressure.

Foot to the floor (where the map is requesting lots of fuel pressure) puts the most strain on the follower. 

[MightyMullet]

So im i right in saying that as my car is standard i dont need to be panicking about this thing imploding?

[Horatio]

What do these things wear like on a 2006 R32??? Im guessing it'll be a roller cam follower? Im due an oil change as well, the stealers want to bend me over and not even offer a reach around 

[GrayMK5GTI]

What do these things wear like on a 2006 R32??? Im guessing it'll be a roller cam follower? Im due an oil change as well, the stealers want to bend me over and not even offer a reach around  

R32 doesnt have the same fuelling system as the GTI and doesnt use a HPFP so you dont need to worry  

@MIGHTYMULLET - If your car has 60k+ miles it will be worth replacing as a precaution as standard cars have failed also. The part is about £28 and can be replaced by yourself with one of the how-to guides on here, or a local specialist will do it for an hours labour

[ARV_90]

Just to clarify, its actually LOAD rather than high revs - you can rev a car on light throttle which will not require a lot of fuel pressure.

Foot to the floor (where the map is requesting lots of fuel pressure) puts the most strain on the follower. 

Good question... depends on how the fuel system works it may make a certain pressure constantly to a fuel rail then electronically meter it as required depending on demand of pressure and volume of fuel required.  If this is the case then load makes no difference the pump makes its design pressure regardless.

I wonder if the HPFP is able to give a bigger flow rate as well as a higher pressure, mapped engines would require both wouldn't they...

Maybe one of the tuning companies could shed a bit of light on it for us.

[GrayMK5GTI]

^^

Fuel pressure is determined by your map. Increased pressure is requested when you increase load on the engine (ie put your foot down), and the pressure is adjusted as per the request. You can see the differences by logging on VCDS.

Generally at idle and light acceleration fuel pressure is low(er), and raises as you increase load with the accelerator pedal .

The fuel pump has a chamber which is filled with fuel and compressed by a piston which is powered by the follower. The higher pressure required means more fuel in the chamber to pressurise which takes more force to pressurise which in turn means more pressure on your follower.

[gazon69]

Little update whilst waiting for parts to arrive. I thought i may as well change the hpfp internals. Never done one before so i just downloaded the one from autotech. Now, looking at the new pump im thinking to myself where the fook do the collats go. Hmmmm lets see. Looks as if my cam has chewed the fecker up along with the spring retainer .

A quick pic with old at the side of new.



Notice how much of the fp it has eaten away.

[MPS]

What an amazingly sh*t design from VW!