I need help on how to go about this. I have replaced just about every fuel system part there is lol. I should have used the Picoscope first but instead I am turning to it as a last resort.

Anyway this 2016 Tiguan had low compression on 2 cylinders, low fuel pressure codes and crank no start. I did a timing chain , sent the head to the machine shop and the cpmpression issue dissapeared. I was left with p0087.

VCDS is showing 9-11 bar actual out of 40bar specified. I have replaced the fuel pump module lvfp, hpfp, cam follower, spark plugs, coils ,fuel pressure sensor, inectors. I dont know what else to do.

i tested the selenoid of the hpfp with vcds and it cliks. any ideas on what to check with the picoscope or how to go about it?

Good morning Albi,

There is a lot to unpack here.

For a high pressure fuel system to work properly it must have adequate supply pressure. Have you verified your low pressure fuel supply to the high pressure fuel pump? How much pressure is available to the HPFP? Is it 4.0-7.0 BAR?

According to the internet this system defaults to low pressure which means the regulator solenoid is responsible for increasing fuel pressure when energized.

I seem to remember that even if the high pressure fuel system were disabled most engines will start and run on just the low side fuel pressure alone. They wont run well, but they run. Does this engine start at all?

Is there fuel in the tank?
Is the fuel in the tank actually gasoline?

Hi Trevor,

Yes I measured the fuel pressure on the low side before it goes to the hpfp (i connected a mechanical gauge with a T fitting ) and it holds steady at 80-90psi even when i am cranking.

Yes there is fuel in the tank and its gasoline.

This engine doesnt start at all. it cranks but does not start. I took a cam crank correlation capture because I did a timing chain job and i am not confident that I did a good job so I wanted to verify timing. Please let me know if I should change the settings in the capture to get a better capture

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500ms/div screenshot

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Omg I am off by a tooth. Look at my 500ms/div sample and look at this known good im uploading now.

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What is the distinctive engine code/letters?

+1 on the engine code and a psdata file please. Also a full engine cycle.

I see 6 gaps and a pull down circuit on your ref and 8 rising on the cam sensor circuit on your capture.

Albi wrote on Aug 10^th, 2026 at 4:32pm:

Yes I measured the fuel pressure on the low side before it goes to the hpfp (i connected a mechanical gauge with a T fitting ) and it holds steady at 80-90psi even when i am cranking.

This is an excellent start.


Albi wrote on Aug 10^th, 2026 at 4:32pm:

Yes there is fuel in the tank and its gasoline.

I only asked because I've seen it bite good techs in the past.


Albi wrote on Aug 10^th, 2026 at 4:32pm:

This engine doesnt start at all. it cranks but does not start. I took a cam crank correlation capture because I did a timing chain job and i am not confident that I did a good job so I wanted to verify timing. Please let me know if I should change the settings in the capture to get a better capture

This is why these forums are here. We'll help you get things sorted.


Here are a few notes on the capture you posted. (2016_Tiguan_Guided_test1_-_Copy.psdata)

Your time on screen is too short.
The 20ms/Div means we only have 2/10ths of a second per page and that's not enough to see whole crank or cam revolutions. Bump your timebase up to 500ms/Div.

Your sample rate is higher than needed but its not hurting you. Changing over to a fixed Sample Rate of 1MS/s will give you enough resolution for these captures while keeping your saved file size manageable.

Its a best practice to label your traces if you're going to post them. In this case I think we can figure it out but when your captures get more complex labels help keep the chaos at bay.

Be careful when making timing decisions with VRS signals. in Reply #3 your CKP screenshot shows the negative signal. In Reply #4 your screen shot shows the positive side of the signal. Keep in mind, on Floating VRS sensors the two traces are a mirror image. This means the top of a tooth on the positive trace correlates to the bottom of the tooth on the negative trace. I attached the VRS_Polarity pic below to help show my point. Most people try to use the positive trace to keep things consistent.

I created a .psdata file you can use as a template to redo your CKP/CMP capture. I labeled the channels, set the time base and sample rate.

Bonus points.
If you use a trigger to start your capture you can guarantee you'll get your crank event all on one screen. I would do a single mode trigger on the rising edge of the crank sensor signal at 2 volts with 5% pre-trigger.

When you save your capture you can keep your file size down by removing any unnecessary pages in the saving process. See Page_trip pic below.

Lastly, you can add up to 5 attachments to your post by clicking the little plus symbol near the word 'Attachments" to the left of your screen. See Pic.

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Nikk wrote on Aug 11^th, 2026 at 1:32am:

+1 on the engine code and a psdata file please. Also a full engine cycle. I see 6 gaps and a pull down circuit on your ref and 8 rising on the cam sensor circuit on your capture.

2016 Volkswagen Tiguan 4Motion

* Engine: 2.0L turbo TFSI/TSI
* Engine code: CCTA
* ECU: Bosch MED17.5.2
* Engine ECU part number: 06J 906 027 JP

I tried to upload a longer capture 500ms/div but the website is not accepting it.

Albi wrote on Aug 11^th, 2026 at 5:55am:

I tried to upload a longer capture 500ms/div but the website is not accepting it.

There is a 30MB size limit on attachments for the forums. This is why I showed how to trim pages and manage your saved file size.

I am meeting with the web developer in 10 minutes to hammer out a solution so you can upload captures to our drop site again.

Trevor Thank you for the Template. For some reason when i create a trigger it doesnt capture anything.

I just did another capture and if you compare it to a known good its way off. After the tooth my capture falls on the short rectangle of the cam signal. On the known good its on the wide.

(im uploading the ps.data file. It is 10315kb and the website is not accepting it)


(EDIT: Changed psdatafile to downloadable version. Trevor Schlientz)

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https://www.dropbox.com/t/qs5hZfs04DscxeEI

I just uploaded my capture to dropbox. Let me know if you can open the link. SHould i tear the engine down again, or this doesnt necessarily show that my timing is off?

File attached.

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can't open it.

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It seems toe forums don't like symbols in the file names. I removed the symbols and now it should work. Try it now.

Yes it works now. Good catch. I didnt know what was going on because it accepted my first capture and then it wouldnt accept the rest.

Do you have any ideas btw Trevor what is going on with my capture? It seems its completely off but there is no way my timing was that off because I followed the timing marks. Worst case scenario I could have been off by one tooth or two maximum but the capture shows im completely off. Is this a phaser problem, or do I have a different style camshaft with a different reluctor wheel? Again like I said there is no way I am off by this much. I got perfect compression and leakdown test shows perfect results on each cylinder

Could I possible have installed the chain wrong? meaning i installed it when the cylinder 1 piston was at tdc but on the exhaust stroke as opposed to the compression stroke? This is the only way i can make sense of how the camshaft signal is so far off from the known good

I'd say the cam is off.

I found a known good from FB and comparing the two I come up your cam being ~84° advanced compared to the KG.

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Albi wrote on Aug 12^th, 2026 at 1:19pm:

Yes it works now. Good catch. I didnt know what was going on because it accepted my first capture and then it wouldnt accept the rest. Do you have any ideas btw Trevor what is going on with my capture? It seems its completely off but there is no way my timing was that off because I followed the timing marks. Worst case scenario I could have been off by one tooth or two maximum but the capture shows im completely off. Is this a phaser problem, or do I have a different style camshaft with a different reluctor wheel? Again like I said there is no way I am off by this much. I got perfect compression and leakdown test shows perfect results on each cylinder

I wonder if this is a case of the tone ring shifting on the camshaft?

I don't think a phaser is going to move as far as it would seem this signal is off. 

Do you think I installed it wrong? Instead of true tdc (piston on cyl 1 was at tdc) but maybe it was on the exhaust stroke as opposed to the compressin stroke

Albi wrote on Aug 12^th, 2026 at 1:19pm:

I got perfect compression and leakdown test shows perfect results on each cylinder

When you say perfect compression what do you mean exactly? Its not  really high is it?

Is this an engine you can remove the valve cover and observe the lobes while rotating the engine?

Albi wrote on Aug 12^th, 2026 at 1:31pm:

Do you think I installed it wrong? Instead of true tdc (piston on cyl 1 was at tdc) but maybe it was on the exhaust stroke as opposed to the compressin stroke

TDC is TDC until the cam is connected to the crank. There is no exhaust or compression stroke until the cam is connected to the crank.

TrevorSchlientz wrote on Aug 12^th, 2026 at 1:35pm:

Albi wrote on Aug 12th, 2026 at 1:19pm: I got perfect compression and leakdown test shows perfect results on each cylinder When you say perfect compression what do you mean exactly? Its not  really high is it? Is this an engine you can remove the valve cover and observe the lobes while rotating the engine?

Every cylinder is at around190psi, and when i do the leakdown test there is barely any air escaping from the cylinders.

and no unfortunately this is the design where the valve cover holds the camshafts down.

Albi wrote on Aug 12^th, 2026 at 1:41pm:

and no unfortunately this is the design where the valve cover holds the camshafts down.

Damn.

This video seems to explain the timing of this engine rather well. https://www.youtube.com/watch?v=B-nQ9nj-C0M

I have to call it a day. I'll check back tomorrow.

TrevorSchlientz wrote on Aug 12^th, 2026 at 1:55pm:

Albi wrote on Aug 12th, 2026 at 1:41pm: and no unfortunately this is the design where the valve cover holds the camshafts down. Damn. This video seems to explain the timing of this engine rather well. https://www.youtube.com/watch?v=B-nQ9nj-C0M I have to call it a day. I'll check back tomorrow.

Thsts actually the exact video I followed when I installed the chain lol.

Perhaps the thing to do is backup and restart this process.

Lets ignore for a moment all the service that's been done and look at this as a new project.

Here is my comprehension of the situation. Let me know if I got something wrong.

A 2016 Volkswagen Tiguan 4Motion is a no start.

* Engine: 2.0L turbo TFSI/TSI
* Engine code: CCTA
* ECU: Bosch MED17.5.2
* Engine ECU part number: 06J 906 027 JP

There is a history DTC or P0087 - Fuel Rail/System Pressure - Too Low Bank 1

The low side fuel pressure has been verified to be 80-90PSI cranking.
A manual compression check shows all cylinders ~190psi
A leak down test has little to no leakage.

There are concerns the engine MAY be mechanically out of time.


The next step is scan data collection.

Are there any codes that set on or after cranking?
Is there an RPM value in the pid data when cranking?
Is there a Cam/Crank sync pid? Does it ever indicate that a synchronization has been achieved?

Next we get more invasive.

Is ther spark from any ignition coil?

How am I tracking so far?

Yes you got everything right so far.

“Are there any codes that set on or after cranking?” - No codes are set after cranking. Actually after I clear the codes no codes come up.
“Is there an RPM value in the pid data when cranking?”- yes between 250-500 rpm and then it dies
“Is there a Cam/Crank sync pid? Does it ever indicate that a synchronization has been achieved?” Not sure. I think you can’t check with the vcds the position of the phaser during crank. I think the car has to be at idle
Yes there is spark

UPDATE:

I went and tore up the cam covers and verified that timing is set perfect. So the question is what the hell is going on how am I 80+ degrees advanced?
Is this a phaser problem? Has the elector wheel shifted on the intake camshaft? Here are the pics below that verify timing integrity of the camshaft.

Something weird popped up. I noticed that when the crank and cams are at TDC , the number 1 piston is not. I updated a picture you can see by the hone pattern on the borescope how far cylinder 1 is from tdc.

How is this possible? Cams are set to tdc, crank is set at tdc, piston 1 is not where it is supposed to be which is TDC!! Did my crank sprocket slip from the special flat spot? or does my crankshaft have a mechanical problem?

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I have done the timing of this engine quite a couple of times....

These engines feature hollow camshafts with pressed on cam lobes that can and will shift when overheating and/or with lubrication issues. Your cams are supposedly new and shouldn't be affected. Nevertheless you may have a look where the lobes point at when the camshaft marks align with TDC on #1.

The lower chain(s)' drive mechanism is a bit unorthodox, there is a kind of knurled, tapered screw that defines the lead/position of the related sprockets directly and indirectly. Though it  would be hard to misalign this one you may want to look at it a second time as this my cause the piston not being at TDC while the marks all do align.

Also this is an interference engine and with that much of true misalignmet I am convinced you would have bent valves and you would not measure190 psi of compression.

If you put the piston to true TDC where is the crank alignment mark then? Is it possible you may have misread the crank mark?

Albi wrote on Aug 13^th, 2026 at 3:14pm:

Did my crank sprocket slip from the special flat spot?

Right now thats what I'm bettin.

You've gone this far. It can't be that much more work to take that lower gear off and make for certain the crank is in the correct location.

Bingo!

The flat part of the crank sprocket got crushed therefore crank sprocket slipped from the crankshaft about 80 degrees.

If you look at the pics, the flat part on the crankshaft is at 9 o clock(where my finger is), and it’s supposed to be at 12 o clock . That explains why piston #1 wasn’t at TDC. I’m surprised it didn’t bent valves. I hope I don’t have a surprise when I put everything back.

P.s. I love how the volkswagens dont throw a code when timing is off. instead it throws a fuel pressure code lol.

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Isnt closure so sweet. 

[smiley=rockon.gif]

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TrevorSchlientz wrote on Aug 14^th, 2026 at 8:36am:

Isnt closure so sweet.  [smiley=rockon.gif]

100% it is. I have been so happy ever since i verified it, nothing else can ruin my day or this feeling.

But most importantly I am happy it happened this way. because I must have thrown 1000$ or more in fuel system parts lol without bringing the Picoscope out. Now the first thing I will do in the future is bring the Pico out

I just finished retiming it. Before putting the timing covers pack on I cranked it and captured the cam+crank waveform.

It looks like it is on time this time around but I need to do some more redearch on how to compare the known good and my capture in the same screen. In the meantime can you guys please help me verify if timing is good?

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Here's a visual side by side with an edge count.

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That looks like it is on time.

Albi wrote on Aug 14^th, 2026 at 7:55pm:

That looks like it is on time.

Yes, it does/is. 8-)

Albi wrote on Aug 14^th, 2026 at 8:57am:

TrevorSchlientz wrote on Aug 14th, 2026 at 8:36am: Isnt closure so sweet.  [smiley=rockon.gif] 100% it is. I have been so happy ever since i verified it, nothing else can ruin my day or this feeling. But most importantly I am happy it happened this way. because I must have thrown 1000$ or more in fuel system parts lol without bringing the Picoscope out. Now the first thing I will do in the future is bring the Pico out

This! This is what we need to convey to the world. This is is the reason why, right here.

Good job on sticking with it and seeing it through Albi.

This the type of experience that will pay dividends for years to come.

Thank you for making the cam+crank template for me Trevor. Not knowing how to use the Picoscope is the reason why I have shelfed it for so long. I was getting anxiety just thinking that I have to read wiring diagrams and take appart the ecm to probe the wire for the crankshaft.

Thank god I took it out and decided to come to this forum because this experience took that fear away and it gave me a new gift where now I am excited and looking forward to the next time I have to use the Pico.
I will go into a deep dive and watch the Learning Vault videos on Autonerdz on how to use Pico7

Honestly thank god for the pico. Its such a rock solid way to identify an issue without tearing stuff down and without wasting money and time throwing parts at the car. On top of that you take a big mental beating everytime you spend time replacing parts and then get dissapointed when the problem doesnt go away. God only knows what I went through with this car.

I'll definitely be in group therapy this month. This is a good case study to talk about if we have the time.

Oh and another thing. I should have paid attention to this detail. So even though the car was crank no start, it used to stall after a few cranks and i would have to hold the brake and turn ignition on again to get it to crank, and it wouyld stall again and the cycle would repeat.
Yesterday when i got timing right, there was a nice beautiful long smooth crank, it didn't stall. But because I lack experience doing timing chains (this is my first timing chain ever) I didn't pick up on the clue that the crank then stall problem was a deeper issue. My waveforms should it as well, there were short cranking sessions followed by no signal and then a crank signal again.

Car purs like a cat. Thank you so much guys. /Fixed

Lucky you ::).
I am surprised no valves were bent and the compression you had with the timing off.

JÜJA wrote on Aug 15^th, 2026 at 8:07pm:

Lucky you ::). I am surprised no valves were bent and the compression you had with the timing off.

Yea lol I don’t know how I didn’t bend valves.