Author Topic: Loss of Boost  (Read 1573 times)

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jyoung

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Loss of Boost
« on: Aug 13, 15, 11:16 »
I'm not 100% sure, but I have a feeling it's my DV.  When I have my foot into it, it feels like the car hits a flat spot when accelerating.  Even when driving normally, it sounds like my DV is open under acceleration.  I do have a stage 1 APR ecu flash and the PO told me the DV was done at the same time, so I can assume it has the R1 DV.  Any thoughts?  Thanks.

Schmiesus

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Re: Loss of Boost
« Reply #1 on: Aug 13, 15, 11:25 »
Engine light?

jyoung

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Re: Loss of Boost
« Reply #2 on: Aug 13, 15, 11:59 »
No engine light.  PO had replaced the coils with an upgraded version.  It is still quick, it just hits a flat spot when it feels as it shouldn't. 

Schmiesus

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Re: Loss of Boost
« Reply #3 on: Aug 13, 15, 12:07 »
What RPM

jyoung

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Re: Loss of Boost
« Reply #4 on: Aug 13, 15, 16:09 »
I would say over 4000 rpm it starts to teeter off.

Schmiesus

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Re: Loss of Boost
« Reply #5 on: Aug 14, 15, 07:43 »
It's most likely normal. Get a VCDS and log it. I gotta do some boost logging for someone interested in the wagon tonight.

jyoung

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Re: Loss of Boost
« Reply #6 on: Aug 14, 15, 21:02 »
VCDS??  I had read that having the blow off valve that dumps into the atmosphere and not recirculating back into the intake can mess with the MAF and in essence it sends less fuel.  Make any sense?  I was told to just go with a better DV.

Schmiesus

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Re: Loss of Boost
« Reply #7 on: Aug 14, 15, 21:06 »
You want a DV in the newest Oem rev. But you will get a code if it's an issue. You can do logs via vcds and see if the car is doing what is expected of it.

jyoung

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Re: Loss of Boost
« Reply #8 on: Aug 16, 15, 23:17 »
checked the dv and it's recirculating.  Maybe worn?  And vcds, how do I log what the car is doing?  Something I plug into?  Thanks.

Schmiesus

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Re: Loss of Boost
« Reply #9 on: Aug 17, 15, 06:18 »
You go into the advanced measuring blocks select the boost specified and boost actual and you see if it's meeting its targets. You will also probably note that boost pressure is specified the decrease as the RPM climbs.

Schmiesus

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Re: Loss of Boost
« Reply #10 on: Aug 21, 15, 13:52 »
You want to create a chart like this


jyoung

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Re: Loss of Boost
« Reply #11 on: Sep 05, 15, 22:59 »
So, I replaced my DV today with an APR R1 DV (thanks PG Performance) and it seemed to fix my issue.  Car feels smooth and the "flat spot" is gone.  I think the old DV was a cheapo unit.  I do thank everyone for the input.   :thumbup:

Schmiesus

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Re: Loss of Boost
« Reply #12 on: Sep 05, 15, 23:29 »
Nice work