Low acceleration at low speed and low rpms, but high boost


  #1  
Old 08-30-20, 10:20 PM
G
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Low acceleration at low speed and low rpms, but high boost

I uploaded a video sample of the problem.
https://youtu.be/bPp6VOeu6-g

You will notice that I am only going about 1900 rpms, 60 km/h yet my boost defi gauge is reading 0.5 bar very high boost. Only at low speeds, low rpms, I feel the car struggling to accelerate and the boost will just hang at 0.5 bar so I don't want to lug the engine by flooring it.

In the past when it was fine, I could easily get up to 80 km/h without going over 2000 rpm and not going into boost either. Then one day it suddenly lost acceleration power under low speed or from stand still. It wasn't like a gradual thing. It just went from working fine before and the next this sudden loss of acceleration.

Any idea what could be causing this?
 
  #2  
Old 08-31-20, 04:23 AM
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Make/year/model/mileage .........
 
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Old 08-31-20, 05:06 AM
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First, tell us what vehicle you have.

Then, since you've bolted a boost gauge to the dash... what modifications have you made to the vehicle?
 
  #4  
Old 08-31-20, 08:52 AM
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My apologies.
VW 2013 Scirocco R, 2.0L TFSI, gasoline, automatic, 71,000 km, APR Stage 2+ tuned (I didn't do it the previous owner had it done).

Here is a short video clip I recorded to show the correlation between my speed, rpm, and boost. Before this issue, I rarely ever needed to go into boost when driving at low speeds and low rpms. I could easily get up to speed to 80 km/h staying under 2000 rpm and never needing boost (needle would stay in vacuum). If I ever hit 0.5 bar boost, it would be a massive acceleration/pull and driving really fast.

It didn't occur slowly or gradually. It literally went from being completely fine the previous day to the next day suddenly this loss of acceleration at low rpms, low speeds especially from standstill or going up a little hill (increasing the load).

https://www.youtube.com/watch?v=bPp6VOeu6-g
 
  #5  
Old 08-31-20, 07:21 PM
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to me it sounds like your timing jumped. BELT? the added boost makes up for the low compression. very shocked you dont have a CEL on.
 
  #6  
Old 09-01-20, 01:42 PM
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Check if your air ducts are not collapsing under suction. Just watched YT video on that. Guy floors, it, air duct folds in a half.
 
  #7  
Old 09-16-20, 06:12 AM
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Could be a plugged up catalytic converter. Boost is trying to push air through the engine, exhaust isn't letting it out, power is gone.
 
  #8  
Old 09-16-20, 06:47 AM
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Is the car over heating? Running hot?
Normally, depending on how stopped up the catalytic converter is, the engine will run hot. And I'm saying, depending on how stopped up it is. But it is another way to diagnose if its the cat.
Let me say that just because it aint running hot yet......, doesnt rule out the cat.
 
 

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