1987 Audi 5000cs low boost // more info

[Cody Forbes]

Clamp closed the hose that connects the wastegate lower chamber to the intake manifold and CAREFULLY see if the car makes more boost. This eliminates all boost control problems; car should over boost and hit boost cut. If it doesn't either the turbo isn't making pressure or the pressure is being let out..

Knowing that the car is modded I'll also now add that its easily to blow the end tanks off the intercooler. Mine, even with a securing strap, used to leak until I made and welded on some aluminum tanks.

-Cody Forbes (mobile)

On Jan 17, 2014, at 8:41 PM, "Eric Huppert" <ehuppert at hvc.rr.com> wrote:

> Gentlemen,
> 
> 
> 
> Seeing as how my son didn't provide particulars ref his low boost problem!
> 
> 
> 
> Car has an IA ECU. He's also tried the other modified ECU he has.
> 
> 
> 
> Has heavier wastegate spring.
> 
> 
> 
> Don't believe any codes. Wastegate moves freely, clunks as it should.
> Diaphragm was replaced previously. (moot point, bad diaphragm creates over
> boost!)
> 
> 
> 
> Tested/repaired WOT switch. Working properly!
> 
> 
> 
> Disconnected Multi func sensor to ensure overheat signal not being sent!
> 
> 
> 
> Michelin man hose good.  Car has one of my old 20v intercoolers and BPV
> installed. BPV is good. No apparent boost leaks
> 
> 
> 
> Switched out waste gate solenoid, no change. Need to further test. But,
> would think the stiffer wastegate spring would apply a little more pressure
> 
> 
> 
> Additions: 
> 
> 
> 
> Aftermarket exhaust system, no cat etc. definitely no restriction
> 
> 
> 
> He previously had some hinky boost controller going to wastegate. I believe
> he lost boost with that installed. So guess that would eliminate the
> solenoid. That set-up (Ben Swan ECU) would push apx 20 lbs.
> 
> 
> 
> Doesn't have excessive endplay on turbo cold side
> 
> 
> 
> He's currently planning on sending out one of my 20v K24's to have it
> freshened up (smoke at extended idle) if we determine it's the turbo
> 
> 
> 
> Eric 
> 
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