Boost

[Kneale Brownson]

I'd start with a pressure check for boost leaks

Sent from my iPhone

> On Apr 10, 2014, at 3:11 PM, Kenneth <auditude at cox.net> wrote:
> 
> Jay Kempf <jkempf at madriver.com> wrote:
>> 
>> I can get about 1.4-1.5 barr of boost  out of a possible stock 1.7-1.8 
>> on the gauge. Last time it was like that I changed the freq valve and it 
>> immediately responded. So I went and checked the freq valve and with 12v 
>> I get immediate click and release and flow through in the right legs. I 
>> also checked the vacuum lines to and from the freq valve and boost 
>> bypass valve and all the rubber parts around those components. All is 
>> perfect and holding vacuum and pressure. Checked the line all the way to 
>> the fuel pressure regulator and all is fine. I made all that stuff new a 
>> while back. I do not have working cruise control so I need to check 
>> there for possible vacuum leaks I am more guessing electrical. Seems 
>> just a simple leak somewhere would limit boost slightly.
>> 
>> But what other thing could be causing a lack of full boost. The car revs 
>> freely and the boost is not slamming so it seems the bypass is working 
>> anyway. Is there some way to check and see if the wastegate is working 
>> properly, stuck slightly open or something?
> 
> You're getting what equates to "baseline boost," from the WG spring only and without assistance/added boost from the WGFV, which is likely due to the ECU intentionally (not) doing that because it thinks something is wrong, such as the Multi Function Temp Sensor (MFTS) sending a false overheat signal, which is very common.  You can test it by unplugging the MFTS, which will disable the dash water temp gauge, and seeing if you still get the same boost.  If you get the correct boost, then replace the MFTS.
> 
> If that's not the issue, you probably ought to go through the boost problem checklist over on SJM Autotechnik.
> 
> http://www.sjmautotechnik.com/trouble_shooting/20vboost.html‎
> 
> HTH,
> 
> Kenneth
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