Car won't go above 25 mph or 3400 RPM in park - If I can't fix it I will need to get rid of it!

[2002_auto_tdi]

OK, so to recap:

1. Pump replaced, was 11mm (auto box) now is 10mm.
2. Would not rev and will not go over 25mph on the road.
3. Boost requested looks ok, actual is flatlined (zero)

Presumption from no power is that actual really IS zero (e.g. MAP sensor and/or its wiring is not dead, which should throw a code and would put you in limp mode -- you have no code, however.)

IMHO where you go from here is:

0. Verify the N75 output actually goes to the turbo actuator, stick Mityvac on line at the N75 going down to the turbo, look at it and make sure it moves when you apply vacuum. If it doesn't or the Mityvac doesn't hold vacuum the line may have a hole or obstruction. Fix line and/or routing.

1. Tee into the vacuum line from vacuum source to the N75 input port at the valve with the Mityvac (so you have the gauge to read it.) Does it have vacuum with the engine running at idle? If not, figure out why (no vacuum, no boost.) If vacuum is there, reconnect as normal.

2. Tee into vacuum line AFTER N75 toward turbo actuator, put gauge where you can see it. Plug in VCDS, have someone drive car with you in pax seat. Note requested boost. When boost is requested does vacuum show up on the gauge? If not, N75 is either not getting drive signal (wiring) or is not working.

You've got a divergence between boost requested/actual and this started when the pump was replaced due to a failure, and you replaced the turbo. Assuming the pump timing is not WAY out of whack (retarded) my money is on vacuum never getting to the actuator. No vacuum, no boost, no power and with a 10mm pump on auto nozzles without boost you're going to be basically driving a lawn mower. IMHO you have to verify the above are all operating "as expected"; I bet they're not.

Genesis, I feel like I have done alot of these tests already. What do you think about starting from step 2 and then working backwards? Is there a way to simplify when boost is expected? I think I would reasonably just be able to ask my passenger what they see when I am on it no?

Thanks.

 

[2002_auto_tdi]

IMHO if you have an oil sucker (for oil changes either on this or on a boat) the EASIEST is to remove the return line (that goes into the plastic "T" from the pump), plug the "T", attach the oil sucker to the return line and pull a decent vacuum with that. If you don't get clean fuel (you probably won't) hit the key but be CAREFUL; it will pull a CRAZY amount of fuel through there FAST, so as soon as you feel it TRY to start STOP or your oil sucker will now be full of diesel!

That's my "10 second prime", it's never failed me, and has zero risk of getting garbage into the IP and damaging it since you're pulling through the filter.

Man, I don't have one of those. Second easiest option maybe? Also, do you think now would be as good a time as any to just go ahead and change my fuel filter?

I could do this stuff without thinking on a gasser. This is all new to me.

I will buy the sucker if I can get this car back up just to celebrate, lol!

Thanks!

 

[2002_auto_tdi]

Sorry but is injection pump timing and ECU timing the same thing?

Do you have a favorite way to do this with VCDS? Again, overwhelmed with info and sometimes it takes hours to determine whether or not a procedure is legitimate. Usually a good thing but my mind needs a rest at times.

Thanks.

 

[2002_auto_tdi]

https://forums.tdiclub.com/index.php?threads/erratic-n75.491803/ I found it by google, I think this is it

I skimmed through this thread. Any idea whether or not the ECU from my 03 wagon could work as a quick test?

Thanks.

 

[2002_auto_tdi]

Just wanted to add that I swapped the MAF from my wagon but still the same.

 

[Nero Morg]

Yeah any time I do a diesel purge, I try to have a quart. I certainly hope it isn't the pump, but I wouldn't exclude it as the culprit yet...

You can try another ecm, but then you'll have the issue of immobilizer to deal with.

 

[2002_auto_tdi]

Yeah any time I do a diesel purge, I try to have a quart. I certainly hope it isn't the pump, but I wouldn't exclude it as the culprit yet...

You can try another ecm, but then you'll have the issue of immobilizer to deal with.

I guess I will hold off on the ECM until I dance around everything else. Wondering if I simply blew something up and there is low compression.

 

[Genesis]

Do you have a favorite way to do this with VCDS? Again, overwhelmed with info and sometimes it takes hours to determine whether or not a procedure is legitimate. Usually a good thing but my mind needs a rest at times.

Thanks.

Yes; it's easy.

1. Warm car up. The temperature gauge should be pointing straight up. Yeah, I know, it only goes 25mph, but if its cold the info will be wrong.

2. Plug in VCDS, connect to the engine, then go to MEASURING BLOCKS. Select group 000 in the top window and pull them up. Engine at IDLE, out of gear. Switch to BASIC SETTINGS. The glow plug light will flash and the engine sound will change slightly; this is NORMAL.

3. The "timing graph" button will illuminate (lower right corner); press it. Select the correct engine (>1995 ALH.) There should be a point at the intersection of two lines; anywhere in the blue parallel lines is acceptable.

TDIGraph - TDI Timing Checker

 

[2002_auto_tdi]

Yes; it's easy.

1. Warm car up. The temperature gauge should be pointing straight up. Yeah, I know, it only goes 25mph, but if its cold the info will be wrong.

2. Plug in VCDS, connect to the engine, then go to MEASURING BLOCKS. Select group 000 in the top window and pull them up. Engine at IDLE, out of gear. Switch to BASIC SETTINGS. The glow plug light will flash and the engine sound will change slightly; this is NORMAL.

3. The "timing graph" button will illuminate (lower right corner); press it. Select the correct engine (>1995 ALH.) There should be a point at the intersection of two lines; anywhere in the blue parallel lines is acceptable.

TDIGraph - TDI Timing Checker

Man, thanks for keeping it simple! Will rule this out while I attempt to use VCDS to prime the new fuel filter (Side note...just about everything I search is on how to not use VCDS to prime making it hard to find the info I need). I think it's wise to just get that out of the way now.

 

[Genesis]

You MAY have timing wildly off BUT if you have requested boost of "X" and actual is zero then what I posted above IMHO has to be why. The ECU is commanding the turbo to make boost but it is not. This means either you have no vacuum at the solenoid for boost control and thus while it is opening nothing happens, you have vacuum at the solenoid and its opening but the line is broken or obstructed between it and the turbo (thus it cannot pull the actuator), the turbo's actuator does not work (it, or the turbo vanes, are stuck, the actuator is open to atmosphere and thus will not move) or the solenoid is not being pulsed (implicating either the solenoid, the wiring or the drive signal to it from the ECU) and thus while there is vacuum and the actuator and hose to it are fine, along with the vanes, they don't move. This ASSUMES the vacuum lines from the various solenoids go where they're supposed to (I've seen someone manage to reverse the EGR line and ASV lines with humorous results ;-)) Since your MAP sensor is not throwing a code (and it WOULD if the turbo made boost and the MAF produced an implausible signal given what the MAP is reading) it is implausible that the turbo IS producing boost but the ECU does not see it.

Whatever else may be going on if the ECU is asking for boost and not getting it that has to be found and corrected.

 

[Genesis]

BTW depending on the pump you can usually prime it by hooking up everything, cracking #3 (the injector with the wire on it) and wrapping the top with a cloth (it will spray everywhere if you don't), crank (no more than 10 seconds or so at a time with a 2-3 minute rest between) until you get fuel there, snug it up and it should start. Sometimes you have to crack another one after #3, but most of the time once you get one cylinder to fire -- and the needle lift sensor in #3 is the one that tells the ECU fuel went in -- it will start. I prefer the vacuum method as it's a LOT easier, is a one-man job if you're alone as long as you have a 3" piece of fuel line with a bolt in the end for the return T on the filter, it's a 2 minute deal and it doesn't make a mess.

 

[2002_auto_tdi]

You MAY have timing wildly off BUT if you have requested boost of "X" and actual is zero then what I posted above IMHO has to be why. The ECU is commanding the turbo to make boost but it is not. This means either you have no vacuum at the solenoid for boost control and thus while it is opening nothing happens, you have vacuum at the solenoid and its opening but the line is broken or obstructed between it and the turbo (thus it cannot pull the actuator), the turbo's actuator does not work (it, or the turbo vanes, are stuck, the actuator is open to atmosphere and thus will not move) or the solenoid is not being pulsed (implicating either the solenoid, the wiring or the drive signal to it from the ECU) and thus while there is vacuum and the actuator and hose to it are fine, along with the vanes, they don't move. This ASSUMES the vacuum lines from the various solenoids go where they're supposed to (I've seen someone manage to reverse the EGR line and ASV lines with humorous results ;-)) Since your MAP sensor is not throwing a code (and it WOULD if the turbo made boost and the MAF produced an implausible signal given what the MAP is reading) it is implausible that the turbo IS producing boost but the ECU does not see it.

Whatever else may be going on if the ECU is asking for boost and not getting it that has to be found and corrected.

Interestingly enough when I reverse the ASV and the EGR vacuum lines nothing happens. It still runs exactly the same. I thought that was weird.

 

[2002_auto_tdi]

You MAY have timing wildly off BUT if you have requested boost of "X" and actual is zero then what I posted above IMHO has to be why. The ECU is commanding the turbo to make boost but it is not. This means either you have no vacuum at the solenoid for boost control and thus while it is opening nothing happens, you have vacuum at the solenoid and its opening but the line is broken or obstructed between it and the turbo (thus it cannot pull the actuator), the turbo's actuator does not work (it, or the turbo vanes, are stuck, the actuator is open to atmosphere and thus will not move) or the solenoid is not being pulsed (implicating either the solenoid, the wiring or the drive signal to it from the ECU) and thus while there is vacuum and the actuator and hose to it are fine, along with the vanes, they don't move. This ASSUMES the vacuum lines from the various solenoids go where they're supposed to (I've seen someone manage to reverse the EGR line and ASV lines with humorous results ;-)) Since your MAP sensor is not throwing a code (and it WOULD if the turbo made boost and the MAF produced an implausible signal given what the MAP is reading) it is implausible that the turbo IS producing boost but the ECU does not see it.

Whatever else may be going on if the ECU is asking for boost and not getting it that has to be found and corrected.

Copy, I will roll through your troubleshooting suggestions in the order suggested.

Thanks.

 

[Genesis]

The reason I gave you the procedure above is that I'll bet you either have nothing going to the turbo actuator because there's no vacuum on the input to the solenoid, the solenoid is not opening despite being told to or the hose down to the turbo is open or plugged. One of the more-common failures is the actuator itself or the vanes are stuck, but you replaced the turbo so that should not be a factor.

Checking from the output port of the N75 -- applying vacuum with a Mityvac (engine off) and observing the actuator either move or not, and that the Mityvac holds vacuum, will tell you the hose and actuator are good. Checking vacuum at the input to the N75 with the engine running will tell you that the check valve is allowing vacuum to be pulled and the vacuum is sufficient (should be around 27") -- if you had none at all you'd have no power brakes either -- and there isn't a gross leak in the brake booster line, the tubing between the booster line, the check valve, the ball and the N75 input. And finally, checking vacuum at the N75 *output* (toward the turbo) while someone is driving and VCDS is showing that the ECU wants boost will show you whether in fact vacuum is there when the ECU thinks it told the valve to open and thus there should be.

One of those things is, with near-certainty, false and if and when you find it you've found the problem. The probability is very high that you either have no vacuum at the input to the valve (which could be as simple as a jammed closed, fouled or installed backward check valve), there is no vacuum because one of the lines after the check valve is OPEN and thus air is sucked in faster than the pump can build vacuum, the vacuum line to the actuator or the actuator itself is bad or the N75 is not opening despite the ECU thinking it told it to do so (valve is electrically bad, valve is plugged, frequently because the vent was not attached to the clean side of the airbox and over time it got crap in it and seized) or the ECU's signal is not getting there, either due to a wiring fault or (QUITE unlikely but not impossible) a fault in the ECU's output circuit itself.

That you reported hearing a hissing noise when you shut down makes me VERY suspicious that you have an open vacuum line beyond the check valve. If it's a good-sized leak it will prevent building vacuum in the ball, which in turn will mean no vacuum to run the actuator at the turbo and.... no boost. Putting a vacuum gauge (e.g. mityvac's gauge) on a "T" at the inlet to the N75 with the engine at idle will prove this up immediately; if there's no or very little vacuum there then you have an open line somewhere past that check valve or the check valve is either installed backward or stuck closed. But the reason you start at the actuator and work backward is that proving up each piece one at a time will isolate where the fault is instead of banging your head against the wall.

 

[2002_auto_tdi]

The reason I gave you the procedure above is that I'll bet you either have nothing going to the turbo actuator because there's no vacuum on the input to the solenoid, the solenoid is not opening despite being told to or the hose down to the turbo is open or plugged. One of the more-common failures is the actuator itself or the vanes are stuck, but you replaced the turbo so that should not be a factor.

Checking from the output port of the N75 -- applying vacuum with a Mityvac (engine off) and observing the actuator either move or not, and that the Mityvac holds vacuum, will tell you the hose and actuator are good. Checking vacuum at the input to the N75 with the engine running will tell you that the check valve is allowing vacuum to be pulled and the vacuum is sufficient (should be around 27") -- if you had none at all you'd have no power brakes either -- and there isn't a gross leak in the brake booster line, the tubing between the booster line, the check valve, the ball and the N75 input. And finally, checking vacuum at the N75 *output* (toward the turbo) while someone is driving and VCDS is showing that the ECU wants boost will show you whether in fact vacuum is there when the ECU thinks it told the valve to open and thus there should be.

One of those things is, with near-certainty, false and if and when you find it you've found the problem. The probability is very high that you either have no vacuum at the input to the valve (which could be as simple as a jammed closed, fouled or installed backward check valve), there is no vacuum because one of the lines after the check valve is OPEN and thus air is sucked in faster than the pump can build vacuum, the vacuum line to the actuator or the actuator itself is bad or the N75 is not opening despite the ECU thinking it told it to do so (valve is electrically bad, valve is plugged, frequently because the vent was not attached to the clean side of the airbox and over time it got crap in it and seized) or the ECU's signal is not getting there, either due to a wiring fault or (QUITE unlikely but not impossible) a fault in the ECU's output circuit itself.

That you reported hearing a hissing noise when you shut down makes me VERY suspicious that you have an open vacuum line beyond the check valve. If it's a good-sized leak it will prevent building vacuum in the ball, which in turn will mean no vacuum to run the actuator at the turbo and.... no boost. Putting a vacuum gauge (e.g. mityvac's gauge) on a "T" at the inlet to the N75 with the engine at idle will prove this up immediately; if there's no or very little vacuum there then you have an open line somewhere past that check valve or the check valve is either installed backward or stuck closed. But the reason you start at the actuator and work backward is that proving up each piece one at a time will isolate where the fault is instead of banging your head against the wall.

Thanks for all of this. Soaking it in.

 

[2002_auto_tdi]

The reason I gave you the procedure above is that I'll bet you either have nothing going to the turbo actuator because there's no vacuum on the input to the solenoid, the solenoid is not opening despite being told to or the hose down to the turbo is open or plugged. One of the more-common failures is the actuator itself or the vanes are stuck, but you replaced the turbo so that should not be a factor.

Checking from the output port of the N75 -- applying vacuum with a Mityvac (engine off) and observing the actuator either move or not, and that the Mityvac holds vacuum, will tell you the hose and actuator are good. Checking vacuum at the input to the N75 with the engine running will tell you that the check valve is allowing vacuum to be pulled and the vacuum is sufficient (should be around 27") -- if you had none at all you'd have no power brakes either -- and there isn't a gross leak in the brake booster line, the tubing between the booster line, the check valve, the ball and the N75 input. And finally, checking vacuum at the N75 *output* (toward the turbo) while someone is driving and VCDS is showing that the ECU wants boost will show you whether in fact vacuum is there when the ECU thinks it told the valve to open and thus there should be.

One of those things is, with near-certainty, false and if and when you find it you've found the problem. The probability is very high that you either have no vacuum at the input to the valve (which could be as simple as a jammed closed, fouled or installed backward check valve), there is no vacuum because one of the lines after the check valve is OPEN and thus air is sucked in faster than the pump can build vacuum, the vacuum line to the actuator or the actuator itself is bad or the N75 is not opening despite the ECU thinking it told it to do so (valve is electrically bad, valve is plugged, frequently because the vent was not attached to the clean side of the airbox and over time it got crap in it and seized) or the ECU's signal is not getting there, either due to a wiring fault or (QUITE unlikely but not impossible) a fault in the ECU's output circuit itself.

That you reported hearing a hissing noise when you shut down makes me VERY suspicious that you have an open vacuum line beyond the check valve. If it's a good-sized leak it will prevent building vacuum in the ball, which in turn will mean no vacuum to run the actuator at the turbo and.... no boost. Putting a vacuum gauge (e.g. mityvac's gauge) on a "T" at the inlet to the N75 with the engine at idle will prove this up immediately; if there's no or very little vacuum there then you have an open line somewhere past that check valve or the check valve is either installed backward or stuck closed. But the reason you start at the actuator and work backward is that proving up each piece one at a time will isolate where the fault is instead of banging your head against the wall.

Wouldn't the engine still be able to rev past 3400 rpm if it were a vacuum/turbo related issue?

Sorry to be simplistic in my thinking. I am still going to roll through your tests but still need time to prime the fuel system. Of note, this cannot be done via VCDS...took forever to find that out. I will try your second method.

The last part of the test might be a bit hard. Too many moving parts for my little brain. Expected, actual, and vacuum at the same time for such a short period of time. Can any of those variables be simplified or looked at during different runs?

Like run 1, verify a delta between expected and actual?

Then run 2 just look at expected and vacuum to actuator?

Or something like that anyways.

Thanks.

 

[Nero Morg]

See, that's why I don't think it's turbo related. Vacuum valves, line, all that jazz. It did the same thing with the old turbo, and I know of people that have N/A tunes (no turbo) and they Rev up just fine. I've also personally revved an engine with the turbo disconnected and it revved up higher than 4k no problems. Partially why I think it's a pump issue.

 

[2002_auto_tdi]

See, that's why I don't think it's turbo related. Vacuum valves, line, all that jazz. It did the same thing with the old turbo, and I know of people that have N/A tunes (no turbo) and they Rev up just fine. I've also personally revved an engine with the turbo disconnected and it revved up higher than 4k no problems. Partially why I think it's a pump issue.

So I am recalling the sequence of events now. IP leaking. Guru replaced some seals. Pump still leaking after seal replacement and drove it back. About 30 minutes into the 50 minute trip no more boost but could still hit 60 mph. He replaced new seals and it stopped leaking but no boost. Car got slower and slower and then eventually wouldn't start. Guru mentioned IP readings were all over the place and was sure the pump was at fault for the no start. All he had was a bunch of used ones and I don't think he was sure of the status of each. He was right about the pump being the cause of the no start. However, the car makes no power.

 

[Nero Morg]

Man, I hate to question it... But is he that good of a guru to leave you chasing this wild goose?

 

[Zak99b5]

To prime the filter, just use a funnel and pour diesel into the hole where the thermostatic T lives until it is full.

To prime the pump, undo the banjo fitting at the head, and use a Mityvac untill you get fuel.

Then crack all four fuel lines at the injectors, and place rags over/around them. Crank it a few times (it won't start) until the rags are wet with diesel. Snug them lines back down, and it will start.

They "using VCDS to prime the filter" is for a motor that has a lift pump, not the ALH.

 

[2002_auto_tdi]

To prime the filter, just use a funnel and pour diesel into the hole where the thermostatic T lives until it is full.

To prime the pump, undo the banjo fitting at the head, and use a Mityvac untill you get fuel.

Then crack all four fuel lines at the injectors, and place rags over/around them. Crank it a few times (it won't start) until the rags are wet with diesel. Snug them lines back down, and it will start.

They "using VCDS to prime the filter" is for a motor that has a lift pump, not the ALH.

Thanks, just got it primed and the car is running now.

This time I cannot get it to rev past 2400 in park.

 

[2002_auto_tdi]

Going with timing check next as that is logically the next easiest step.

 

[2002_auto_tdi]

Can we move past timing issues now? Am I correct in that this looks good?

http://imgur.com/a/o1Ngbvd

 

[2002_auto_tdi]

Ready to start the "Genesis test" as follows but existing questions and a new question still stand. Please see below:

0. Verify the N75 output actually goes to the turbo actuator, stick Mityvac on line at the N75 going down to the turbo, look at it and make sure it moves when you apply vacuum. If it doesn't or the Mityvac doesn't hold vacuum the line may have a hole or obstruction. Fix line and/or routing.

TEST NUMBER 0. HAS PASSED.

1. Tee into the vacuum line from vacuum source to the N75 input port at the valve with the Mityvac (so you have the gauge to read it.) Does it have vacuum with the engine running at idle? If not, figure out why (no vacuum, no boost.) If vacuum is there, reconnect as normal.

AS TO TEST NUMBER 1., WHICH PORT IS THE INPUT PORT? EDIT: To not waste time, I assumed that it is the top port, the one just above the one that goes to the turbo actuator. Am I correct? If so, I am getting a rock solid 28 in. there. I am watching videos and searching but there really is such a thing as too much information at once.

2. Tee into vacuum line AFTER N75 toward turbo actuator, put gauge where you can see it. Plug in VCDS, have someone drive car with you in pax seat. Note requested boost. When boost is requested does vacuum show up on the gauge? If not, N75 is either not getting drive signal (wiring) or is not working.

AS TO TEST NUMBER 2., again is there a way to simplify this test? Too many variables for even a driver and I at once....especially with a vehicle in this condition. Thanks.

 

[Genesis]

Ready to start the "Genesis test" as follows but existing questions and a new question still stand. Please see below:

0. Verify the N75 output actually goes to the turbo actuator, stick Mityvac on line at the N75 going down to the turbo, look at it and make sure it moves when you apply vacuum. If it doesn't or the Mityvac doesn't hold vacuum the line may have a hole or obstruction. Fix line and/or routing.

TEST NUMBER 0. HAS PASSED.

1. Tee into the vacuum line from vacuum source to the N75 input port at the valve with the Mityvac (so you have the gauge to read it.) Does it have vacuum with the engine running at idle? If not, figure out why (no vacuum, no boost.) If vacuum is there, reconnect as normal.

AS TO TEST NUMBER 1., WHICH PORT IS THE INPUT PORT? EDIT: To not waste time, I assumed that it is the top port, the one just above the one that goes to the turbo actuator. Am I correct? If so, I am getting a rock solid 28 in. there. I am watching videos and searching but there really is such a thing as too much information at once.

Yep. The input port is the one which has a line that (on an unmolested system) goes back to a "T", and from that T one line goes to the ball, the third one goes to a black and white check valve. The other side of THAT ultimately leads to the pipe coming off the vacuum pump.

Sounds like you have solid vacuum there AND the actuator works when vacuum is applied to it. Good; this strongly implies that (1) you have vacuum so the pump and check valve are good (and the check valve is not reversed or stuck) and (2) the actuator works when you apply vacuum to the hose at the N75 end of the line. Since you have vacuum at the input to the N75 and a working actuator on the other end you are now down to one variable -- the N75 itself, and the drive signal to it.

2. Tee into vacuum line AFTER N75 toward turbo actuator, put gauge where you can see it. Plug in VCDS, have someone drive car with you in pax seat. Note requested boost. When boost is requested does vacuum show up on the gauge? If not, N75 is either not getting drive signal (wiring) or is not working.

AS TO TEST NUMBER 2., again is there a way to simplify this test? Too many variables for even a driver and I at once....especially with a vehicle in this condidion. Thanks.

You've got a divergence between boost requested/actual and this started when the pump was replaced due to a failure, and you replaced the turbo. Assuming the pump timing is not WAY out of whack (retarded) my money is on vacuum never getting to the actuator. No vacuum, no boost, no power and with a 10mm pump on auto nozzles without boost you're going to be basically driving a lawn mower. IMHO you have to verify the above are all operating "as expected"; I bet they're not.

You could do it this way, but here's another option since you have VCDS:

1. Put the "T" in with the Mityvac.
2. Start the engine, in park, start up VCDS.
3. Go to ENGINE, BASIC SETTINGS, choose Group 11.
4. You can either watch the numbers or the graph, but also watch the vacuum gauge.

The N75 will cycle every few seconds. You should see the change in the basic settings screen as it cycles (boost pressure) and you should be able to see the actuator move when it cycles; it should go all the way to the stop. You should ALSO hear the change in the exhaust note -- it's quite noticeable. The vacuum gauge should cycle with the N75.

Your timing (assuming you selected the correct engine) is right up on the line for advanced. It's ok there and is relatively common for people to set it there (anywhere in the blue bars is acceptable; further up is a bit "peppier" normally.)

 

[PakProtector]

Even wid no boost at all it should be no issue to get the engine to redline. VWderf I believe is running about with a normally aspirated ALH.

Given the experiment with the bottle( for which only the suction line went to the bottle), the pump drew up fuel at a rate that strikes me as proper.

Casting no aspirations on the whole process here, I would suggest a look at the approved mechanics list in TDI 101, and get the beast there before pulling a sheet over her. I can identify with the desire to pass it along to your son. I did the same. We both bled a bit as we worked on it, and he is quite fond of it. I am PiS happy with the situation( Pig in $..t that is ).
cheers,
Douglas

 

[Genesis]

Pak, he has a 10mm pump with auto nozzles; that thing is a lawn mower without boost, and by his data he has no boost despite the ECU asking for boost.

My money at this point, given the above diags (known good vacuum at the input to the N75 and actuator works when vacuum is applied to the hose at the N75 heading to it) my bet is that the N75 is not working, either electrically or it is mechanically jammed/plugged closed.

There may be other problems too but eliminate that which you can without spending money first.

 

[2002_auto_tdi]

Yep. The input port is the one which has a line that (on an unmolested system) goes back to a "T", and from that T one line goes to the ball, the third one goes to a black and white check valve. The other side of THAT ultimately leads to the pipe coming off the vacuum pump.

Sounds like you have solid vacuum there AND the actuator works when vacuum is applied to it. Good; this strongly implies that (1) you have vacuum so the pump and check valve are good (and the check valve is not reversed or stuck) and (2) the actuator works when you apply vacuum to the hose at the N75 end of the line. Since you have vacuum at the input to the N75 and a working actuator on the other end you are now down to one variable -- the N75 itself, and the drive signal to it.

You could do it this way, but here's another option since you have VCDS:

1. Put the "T" in with the Mityvac.
2. Start the engine, in park, start up VCDS.
3. Go to ENGINE, BASIC SETTINGS, choose Group 11.
4. You can either watch the numbers or the graph, but also watch the vacuum gauge.

The N75 will cycle every few seconds. You should see the change in the basic settings screen as it cycles (boost pressure) and you should be able to see the actuator move when it cycles; it should go all the way to the stop. You should ALSO hear the change in the exhaust note -- it's quite noticeable. The vacuum gauge should cycle with the N75.

Your timing (assuming you selected the correct engine) is right up on the line for advanced. It's ok there and is relatively common for people to set it there (anywhere in the blue bars is acceptable; further up is a bit "peppier" normally.)

Hey Genesis, I previously tried that test with VCDS but I simply watched the actuator cycling. Do you think that I should induce the vacuum gauge into the test? Thanks for answering on the timing. I figured it was right.

I still think that driving with it briefly may hold some value but would need to break the test down to pieces where it is safe to do so like:

Test 1 -

Run it up a private road at full throttle and see if I am getting vacuum from the tee.

Test 2 -

Check actual vs expected boost with VCDS....although my laptop is quite old...I think I'd rather use my VAG401 for this.

Thoughts on that or do you think the VCDS test is the end all?

Thanks.

 

[vandermic07]

See, that's why I don't think it's turbo related. Vacuum valves, line, all that jazz. It did the same thing with the old turbo, and I know of people that have N/A tunes (no turbo) and they Rev up just fine. I've also personally revved an engine with the turbo disconnected and it revved up higher than 4k no problems. Partially why I think it's a pump issue.

I second Nero on this. I had limp mode issues in the mountains one time. It would red line. I wouldnt have made it over the hills if it didn't rev high.

I think it is probably air related. I'm not sure if ASV and EGR were completely ruled out? or the Intercooler is clogged? Is the intake clean?

If not air, the IP might be screwed up. Does anyone know if you check throttle position and the IP position to make sure the peddle and IP are correlating?

 

[2002_auto_tdi]

I second Nero on this. I had limp mode issues in the mountains one time. It would red line. I wouldnt have made it over the hills if it didn't rev high.

I think it is probably air related. I'm not sure if ASV and EGR were completely ruled out? or the Intercooler is clogged? Is the intake clean?

If not air, the IP might be screwed up. Does anyone know if you check throttle position and the IP position to make sure the peddle and IP are correlating?

Hi,

Could I remove the upper intercooler pipe to rule that out? If so, I did that and it still won't rev. New air filter and no snow screen as well.

The ASV and EGR were ruled out (in my opinion) but I can't get over the fact that the EGR starts popping in and out every few seconds immediately after the first rev to redline and continues to do so. That right there says *something*. I just wish I knew what that something was.