My Second 1.6 FSI

[Radian]

I've now purchased another 1.6 FSI, the body work and interior are very good however the engine needs higher revs in each gear otherwise it judders and Im driving it thinking it could break down at any time. I need to find a mechanic with good knowledge of the A2. Ill keep you posted.

 

[PlasticMac]

I've now purchased another 1.6 FSI, the body work and interior are very good however the engine needs higher revs in each gear otherwise it judders and Im driving it thinking it could break down at any time. I need to find a mechanic with good knowledge of the A2. Ill keep you posted.

Maybe one with vcds first?
Mac.

 

[Robin_Cox]

Sounds like a misfire. At the very least scan it with a VAG-compatible tool, and preferably full VCDS being operated by someone who knows what they are doing - the FSi is a complex engine in perfect condition and as many dozens of posts and threads at A2oc bear witness - when it isn't in perfect condition, returning one to full health is not trivial without the correct tools.

 

[PlasticMac]

Maybe one with vcds first?
Mac.

Check Groups 140 & 141, fuel rail pressure. A couple of recent threads/posts point to the electric, tank end, lift pump getting tired. You can only monitor the high pressure pump output, at the fuel rail, but it'll give you clue. Should be 100 bar.
Mac.

 

[JavaGreen]

I had this problem, it took much head scratching to sort out:

it had a service- still the same
turned Out the filter had not been changed for 40k and 7 years, it had started to disintegrate. New filter - still the same
the consequences of the filter disintegration had caused damage in the HPFP so this was changed with a replacement from A2Steve - alas still no change however, it was running much better.
turned out that the fuel rail was partially clogged with bits of the filter, this was overhauled and hey presto fsi running as it should.
That was about 12k miles ago (been serviced since) and still running sweet - love the fsi, a cracking motor

 

[JavaGreen]

If you have space/ and can afford another fsi as a spares mule, I would go down that route. It would be cheaper and most things would be to hand.

I have the fsi and a 1.4 petrol (keeper), they are now on a rotation basis winter/summer respectively. When the fsi gives up the ghost (120k now) I will look for another 1.4 petrol as I can foresee problems for A2 diesel cars with LEZ.

Cheers,
Paul

 

[PlasticMac]

If you have space/ and can afford another fsi as a spares mule, I would go down that route. It would be cheaper and most things would be to hand.

I have the fsi and a 1.4 petrol (keeper), they are now on a rotation basis winter/summer respectively. When the fsi gives up the ghost (120k now) I will look for another 1.4 petrol as I can foresee problems for A2 diesel cars with LEZ.

Cheers,
Paul

I think many of the FSIs that get scrapped, are the victims of ignorance, not intended, but just the same. They have a certain reputation, even on here, which does nothing to help.
From wrong fuel to mechanics who treat them as a typical old banger, which they aren't. The engine is complex, mechanically and technologically, also, (probably), unique. But it has many sensors, to monitor what's going on, and a diagnostics scan tool to match.
They need understanding. They are A2s after all.
Mac.

 

[PlasticMac]

I had this problem, it took much head scratching to sort out:

it had a service- still the same
turned Out the filter had not been changed for 40k and 7 years, it had started to disintegrate. New filter - still the same
the consequences of the filter disintegration had caused damage in the HPFP so this was changed with a replacement from A2Steve - alas still no change however, it was running much better.
turned out that the fuel rail was partially clogged with bits of the filter, this was overhauled and hey presto fsi running as it should.
That was about 12k miles ago (been serviced since) and still running sweet - love the fsi, a cracking motor

I think the threshold for triggering a low rail pressure, in the FSI, is probably set too low. A check of the measuring blocks now and then, would be a good idea.
Even better, log them over a drive. The pressure could be OK at idle, but not under load.
Mac.

 

[JavaGreen]

I think the threshold for triggering a low rail pressure, in the FSI, is probably set too low. A check of the measuring blocks now and then, would be a good idea.
Even better, log them over a drive. The pressure could be OK at idle, but not under load.
Mac.

And that was my problem…. okay up to about 1800rpm then bog down under load. The fuel rail had a slight blockage due to disintegration of fuel filter. Also managed to knacker my HPFP

 

[JavaGreen]

I think many of the FSIs that get scrapped, are the victims of ignorance, not intended, but just the same. They have a certain reputation, even on here, which does nothing to help.
From wrong fuel to mechanics who treat them as a typical old banger, which they aren't. The engine is complex, mechanically and technologically, also, (probably), unique. But it has many sensors, to monitor what's going on, and a diagnostics scan tool to match.
They need understanding. They are A2s after all.
Mac.

They sure do need a little understanding, some patience and loads of tlc

 

[PlasticMac]

They sure do need a little understanding, some patience and loads of tlc

Worth it on a good day though
Mac

 

[simon martyn]

I would recommend speaking to WOM Automotive in Stoke on Trent.

 

[Radian]

Thank you everyone Brilliant replies, I took it out this morning locally and it didn't seem too bad just slight juddering although I was taking it easy not above 40 mph.
Ill keep you all posted. Just love the A2 and I've had many cars over the years. So fingers crossed.

PS the garage I bought it from are willing to pay a little to help out. He tried to say sold as seen. I didn't reply while he was offering to help.

 

[Andrew]

Check Groups 140 & 141, fuel rail pressure. A couple of recent threads/posts point to the electric, tank end, lift pump getting tired. You can only monitor the high pressure pump output, at the fuel rail, but it'll give you clue. Should be 100 bar.
Mac.

Good Evening Mac,

On the subject of "no sensor on the low pressure fuel delivery pipe to the HPP to monitor the pressure generated by the lift pump".

Just an idea, IF the HPP does not act like a valve then the value in the fuel rail shown by measuring group 140 with engine off is the pressure in the low pressure fuel delivery pipe? My FSI just now with engine off.

@Radian

I have a memory of fuel rail pressure of about 60 bar at idle. It does increase with engine revs up to 99 bar. The top end of the value range is actually 120 bar but by a quirk of VCDS the display field seems limited to two digits, that is it maxs out at 99 bar.

Andy

 

[PlasticMac]

That's a fine bit of logic, and a good measure of the electric pump. One more step in that logic is the same, engine off, ignition on, but with a hot engine when the bypass circuit is closed, and the electric pump should give 5.2 bar. The pressure relief, (safety), valve is 120 bar, I think, (I'll check later).
Another FSI step forward.
Mac.

 

[Crgwal]

Okay, with advice from Mac this is what I have done.

Posted a picture of hot engine running. (you can see 100bar if no decimal place FYI)

Posted a picture of hot engine off.

Posted a picture of hot engine off (after turning engine for a split moment)

Posted a graph of the hot engine off, followed by a start-up then running for a short time. The arrow shown is the low point the revs dropped to after starting the engine. This was nearly a full stall. (For those that don't know I am having hot engine start troubles)

 

[PlasticMac]

Because the lable file, which has the on screen text, does not exist in English, the text under the blocks is wrong.
The pic below shows how it should be. @Andrew is working on a genuine lable file, with some help from Ross-Tech, but mainly helped by @Seb_Gurkyh and a but6frim me. Andy will post it up, for downloading, once it's done.

So your pressures are OK, the Actual is what you have, while Setpoint is what the ECU asked for.
It doesn’t help with the lift pump pressure though.
This is a bit "suck it and see" because we don't know how much pressure the HPFP retains, (like a one way valve).
If possible, could you look at 140 again, but when the engine's been off for a while, so that any residual high pressure will have dissipated, and then when the ignition goes on, hopefully, we'll see the lift pump pressure. Sorry to be vague, but we don't know yet.
Mac.

 

[PlasticMac]

Because the lable file, which has the on screen text, does not exist in English, the text under the blocks is wrong.
The pic below shows how it should be. @Andrew is working on a genuine lable file, with some help from Ross-Tech, but mainly helped by @Seb_Gurkyh and a but6frim me. Andy will post it up, for downloading, once it's done.
View attachment 107446
So your pressures are OK, the Actual is what you have, while Setpoint is what the ECU asked for.
It doesn’t help with the lift pump pressure though.
This is a bit "suck it and see" because we don't know how much pressure the HPFP retains, (like a one way valve).
If possible, could you look at 140 again, but when the engine's been off for a while, so that any residual high pressure will have dissipated, and then when the ignition goes on, hopefully, we'll see the lift pump pressure. Sorry to be vague, but we don't know yet.
Mac.

The vcds screen above is from @Andrew ignition on, engine off.
Mac.

 

[PlasticMac]

Just had a look at the description and cutaway drawings, of the HPFP, and there are valves on the inlet and outlet of the pump.
The two valves are not open at the same time, so the pump will act as a non return valve.
From Andy's VCDS example above, pressure does dissipate, so ignition on after a while, should give the lift pump reading, hopefully.
I'd check mine, but I've got a poorly Mrs Mac who takes precedence.
That might make the hot engine reading difficult though ...
Mac.

 

[PlasticMac]

Group 140 block texts are, (or should be, but aren't), as Andy's pic above, that is:

Block 1: Rail Pressure,Regulating Valve
Block 2: Rail Pressure,(Setpoint)
Block 3: Rail Pressure,(Actual)
Block 4: System Pressure,Test

Group 141 block texts should be:
Block 1: Rail Pressure,Regulating Valve
Block 2: Rail Pressure,(Setpoint)
Block 3: Rail Pressure,(Actual)
Block 4: Rail Pressure,System Status

The block text you see on your screen are irrelevant, because the English label file does not exist, so VCDS makes a guess, and it's not quite AI.

Mac.