[SpooleyMcGillicuddy]

Hello this is my first post on the forum so bear with me, but my 2003 Passat has a stage 2 ecs tune. I believe it’s ecs not entirely sure, but it’s definitely a stage 2 I swapped it from a 2000 Passat where it only made 10lbs of boost consistently but occasionally would hit 20 and creep down to 10 as I neared red line. I put it onto my 03 and it made 18 lbs for a couple days then dropped to 10 lbs. I’ve scoured the vacuum lines for leaks and have found none, I’ve used maf cleaner and cleaned all of the sensors in the inter cooler piping and manifold/throttle body to no avail. I recently put a k04 hybrid on with a brand new waste gate that operates perfectly so it’s not the wastegate. I currently have an mbc on but I hate the way it boosts so aggressively and even the mbc has trouble keeping the boost above 15 for very long, I completely lost and any help would be appreciated greatly.

 

[PZ]

As far as I know, ECS never sold their own tuning for a car. A 2000 tune should not work on a 2003 Passat as their are multiple differences in the electronics. You need to list the ECU and find out what tuning is on it. I think the 2000 ecu ended with BG for Tip models.

 

[SpooleyMcGillicuddy]

Well the computer is for a 2002 Passat and I ran it on a 2000 for 2 years with no issues there was a code being thrown for a camshaft position sensor open circuit lol which I attributed to the lack of the vvt

 

[SpooleyMcGillicuddy]

But a guy I met at a car meet worked at a tuning place in northern va said the hand writing on the ecu looked like something from ecs, and he seemed very knowledgeable. I just no it should be boosting around 18lbs but won’t do it consistently anymore. I should’ve added when it first started to lose boost on the 2000 I cleaned the maf and it held 18 for about a week before dropping back to 10

 

[PZ]

I would check the DV. Do you have vagcom? If not, you need it to check your fuel trims and requested vs actual boost. With a hybrid K04, you might be running too lean to hold that much boost. Usually they require larger injectors.

 

[SpooleyMcGillicuddy]

I have a forge 007 diverter and it’s off of a car that held 20psi no problem. And the boost issue started before the k04 went on, and I had the same k04 hybrid on the 2000 Passat that held 18 for a while before dropping that’s why I was thinking sensor or leak. I’m waiting for a vagcom right now I ordered it last fri

 

[AndreasPassat]

I'm not much of an authority on turbo set-ups, but I thought with our cars once you got over certain amount of boost you had to disable the VVT, mess around with fuel trims and put in bigger injectors depending on how big and how much the turbo spooled up.
I do know high PSI with a supercharger required the VVT being disabled. I remember having a lengthy discussion on this topic with the guys at 034 Motorsport years ago.

I agree with PZ. A tune for a 2000 is not a tune for a 2003. Revisions in electronics were made through those years and things are not exactly the same.
Yeah it may have worked, but the tunes ARE different.

Again, I'm not a turbo guy, but if your losing pressure the higher the RPM is something is wrong. Once the turbo spools up, it should continue to build pressure until you let off the gas pedal.
The velocity at which the charged air moves through the engine is some proportionate value of exhaust and intake air. Something in this proportion is being disrupted if the pressure drops off.
To me, it sounds like the exhaust is being restricted or not allowing the engine to breath properly. I'm just guessing here.
Look at it this way, if you take a leaf blower, put your hand over the outlet, the impeller will rise in RPM but the pressure will drop off considerably.

 

[SpooleyMcGillicuddy]

Well the computer is for a 2002 Passat, I used it in the 2000 because the car was $500 and was terribly slow. But it ran like a scolded beast with that tune. Anyhow the 2003 is nearly if not identical to the 2002 that it was originally off of. thank you guys I appreciate the input, but so far I don’t think your ideas are what’s causing the boost loss.i should’ve stated all the mods I’ve done to it.
•3 inch test pipe-2.5” straight pipe
•manual boost controller
•forge diverter relocated to driver side
•k04 hybrid
•2.5” intercooler piping and fmic
But I’m currently running a cheap eBay diverter to rule out the forge diverter causing the problem and no difference. (But it does sound cooler)

 

[SpooleyMcGillicuddy]

And also it’s not just at higher rpm sometimes it won’t boost over 10 psi at all, but when it does hit 18 it slowly falls until it hits 10psi

 

[PZ]

I think the vagcom is needed to solve the issue. I am not big on 1.8T Tuning, I only had a chip on my 2000 1.8t and my 2001 is still stock. It could be many things, from fuel trims to a collapsing turbo inlet (if oem). The IC and exhaust seem to be good.

 

[SpooleyMcGillicuddy]

I forgot to mention silicone tip, and I’m still waiting on the vagcom. The person I ordered from is not emailing me back and the tracking # doesn’t come up on fedex. But I’m starting to suspect the wastegate because it will spike to 18 if I give it the perfect amount of throttle and hold it, but sure enough it begins to drop after a couple seconds if not sooner

 

[SpooleyMcGillicuddy]

Could the pcv system cause boost loss if the checkvalve isn’t operating properly?

 

[PZ]

It could, but you would have blown oil seals as a result. Usually when a wastegate fails, you end up with no/low boost.

 

[SpooleyMcGillicuddy]

Oil seals where? And I’m wondering if the wastegate is opening to much not exactly failing but just acting up. I’m just thinking the mbc is the only thing setting the boost I completely bypassed the n75 to see if that would give me a consistent boost above 10 at all which it does but it Still drops to 10 eventually with just the mbc

 

[PZ]

A bad PCV check valve could cause any of the oil seals to blow out, it's just a question of which gives way 1st. It could be a cam seal or either of the front/rear crank seals. The valve cover gasket would probably leak too, but with boost pressure in the crankcase, it would blow more than just the valve cover gasket.

 

[SpooleyMcGillicuddy]

Recently there’s been oil on top of the oil fill cap its self, and a little smoke when exiting the highway Decelerating from 80 miles an hour. So I’m betting the pcv is going bad. The car has 200,000 on it so it’s about that time.

 

[SpooleyMcGillicuddy]

Sorry to go off topic but the rosstech that I ordered has been stopped and the money refunded by PayPal so I’m about to order another one. I was wondering what’s the difference with the cheap eBay ones they all say 409.1 but the prices vary a lot some come with a disc others with a link to download something. I

 

[SpooleyMcGillicuddy]

Wait how could boost pressure get into the pcv if it is before the turbo? I thought the pcv vented into the tip?

 

[PZ]

The PCV is dual vented. Into the manifold under vacuum and into the tip during boost. That's why the rubber T is there, to split between them with the one-way check valve stopping boost going back into the system. There is also a pressure control valve (often called the hockey puck), to limit how much vents into the tip.

 

[scotts13]

Sorry to go off topic but the rosstech that I ordered has been stopped and the money refunded by PayPal so I’m about to order another one. I was wondering what’s the difference with the cheap eBay ones they all say 409.1 but the prices vary a lot some come with a disc others with a link to download something. I

The only legal and safe way to purchase VCDS is from the Ross-Tech web page. Any other source is either a fake or a (probably virus-infested) ripoff. IF you wish to use the "free" version, you download it from Ross-Tech then hunt up a USB-to-OBDII cable. There are many out there (some work and some don't), but NEVER load the software disk that comes with them.