No Boost After Shifting?

Started by Rixio, October 12, 2007, 06:25:15 PM

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Rixio

Im usually quite good at troubleshooting but this one has me stumped...

The car was mapped 2 days ago and this problem wasnt there when it was mapped or being mapped. It happened afterwards...possibly on the way home.
I noticed when i got home that the Charge Control Actuator (Y pipe one) wasnt connected to the plenum & there was a split in my elbow. Both have been rectified, but now have another problem.

If i drive nice and steady. I.E 1/4 throttle...when the car gets to 2-3k it starts burbling/sqealing up to 5k...not like its a mapping issue, more like a turbo/vacuum issue...if i floor it it seems to disappear :Hammer

If i shift through the gears...I.E 2nd to 3rd. I lose boost and have nothing until i lift off and re-apply throttle...at which point i have positive boost

BUT if i leave it in 2nd from e.g 2k and floor it, it goes all the way to redline without incident...

:Hammer :Hammer :Hammer Its difficult to explain...:Hammer :Hammer :Hammer

This sounds similair...

"Chris Davis Adds
After reassembling everything on the car I was getting full boost in both turbos including a nice transition from the primary to the secondary. The problem was between 2000 rpm and 4500 rpm I kept getting a loud squeal coming from under the intake plenum. I narrowed down the noise to the air control valve (ACV). I removed the intake plenum again but could not find anything wrong with the ACV. I finally received advice from Dave at Blackstone Performance. I told him my problem and he told me to open the ACV and check to see if the metal disc had slipped down a little while I was reinstalling the valve. I loosened the three nuts on the valve and sure enough the disc was not flush with the intake manifold (I could tell because it left an imprint in the black carbon build-up). I tried to pull the metal disc up with a screw driver but the disc kept falling back down. In order to make the disc stay in place, I had to remove the solenoid rack (again) and pull the valve completely off. Next, I put a little rubber cement around the disc (from the advice of Dave) to give the piece a little tackiness so it wouldn\'t fall off again. After reassembling everything, another sore back, and much frustration the car runs perfect with no annoying chirps.
I also learned in the process (from Dave) that the ACV is only active between 2000 and 4500 rpm which is what clued him in to the problem. I can also remove the intake plenum in about 15 minutes but I hope to never have to remove it again. Anyway, I just thought you might want to mention something about the ACV disc to save someone else the headache of having to remove the solenoid rack twice. Once, as you know, is plenty.
Chris Davis"

^^^^^That means nothing to me and really dont have a clue what hes talking about but the problem sounds similair...^^^^^^^^ (Or is that just me being thick)

John (Warthog) had the same problem a few years ago and said it was something that could only be done under the car...to me it sounds like an actuator on the turbo...

Tmrw im gona check all the one way check valves to see if thats the problem...but i thought id best post incase its something simple to fix

O ye great FD guru\'s...please helpeth me in my hour of need...

Rixio :cheers

Jono FD3

I had a similar issue mate..... I put the car on the pit to take a look and found 2 split pipes!! the pipes are to an actuator type thing.... You have your wastegate actuator & a pre spool conrtole actuator thingy... then there is a 3rd unit, same diamiter as a coke can, but not as long..... the pipes on this were my problem!! might be worth a look!!

Jono

Rixio

I keep splitting those pipes...replaced 3 today...along with loosing 2 brand new number plates ffs!