I've done a quick search and found one thread with a similar problem, but here was no solution so here goes again

Has anyone else ever experienced a strange boost phenomenon, where the STi starts to boost hard at 4000rpm or so (1.2 bar) but then shutdown boost suddenly to 0.5 bar?

My STi did this today and its only because I recently installed the gauge that I can tell whats going on. I'm sure I've felt something similar before I had the gauge but couldn't confirm it.

Both times it has been in fifth and after it happens I cant get boost above 0.5 bar in any gear for about 2 minutes or so.

It has returned to normal now - but I'm at a loss as to why it may happen - particularly since my car is stock

Concerned, I took it into a dealer and got the diagnostic tool on it, but no fault codes were there. He reset the ECU and the drive home was fine. The only things I can think:

The boost solenoid is sticking shut intermittently, leaving me with the wategate spring pressure of .5 bar
or
The ECU is pulling the boost back because of knock (but not sure why it would knock)

Ideas?

 

Sorry to be not much help but as said, there isn't much difference between the STi7 and STi8

Had the same thing happened once with my STi7 and once with or twice since PPP'd, I haven't got gauges but felt a distinct lack of boost
Once was (PPP) at Rev limit in 5th then 6th no or little boost but was told don't expect much at that speeds

Hope all the fatal engines don't happen on the 8 as the 7. should be better with PPP EcuteK map and maybe a better Fuel Pump

 

Get it to a dealer or DeltaDash owner pronto - there are multiple reason for the ecu to shut down boost, most of them bad.....

Richard

 

No expert but it sounds like the Ecu is pulling boost due to knock. What fuel are you running, hopefully at least 95RON? I also imagine you are having hot weather there and could be getting heatsoak while stopped or in the traffic.

 

Yep - concurred - here in sunny hot South Africa, with a dose of the wrong fuel and high ambient temps boost cut happens as described.

 

Sorry boys didn't realise you boys were from down under and sunny climates
The weather is cold and Snowy here so heat soak wouldn't have been a problem in the UK


For what it's worth get your Fuel Pump Checked/replaced/upgraded if upgraded will need to do the fuel regulator aswell (so I have been led to believe) some peeps here have had it going like a bag of **** and/or leaning out recipe for melting pistons etc,etc, IMHO

Tony

Ps not knowledgably just passing on what I have been told

 

Tony - told by whom?

Richard

 

To be 100% honest & to definitely back up T5NYW (Le Mans Geezer) view, even the EcuTeK Sti7 tends to have good and bad days. Always ***** fast but different amounts of smoothness.

Tyres wearing like sh*t also mate!

I put it down to STi7 being like birds....good days & not so good days, but generally better to have one than not!

 

Thanks for the info guys,

But the car does not have PPP fitted, or indeed any mods - I certainly haven't heard audible knock (and I know what it sounds like). Have already been to a dealer and the Select monitor doesn't show any dramas. Only ever happened twice and both in 5th gear.

 

Paul
god to here from you again Hope all is well I seem to remember you said at Le Mans your top speed limiter cut in at ***mph mine since PPP cut out ***mph thats 5 mph lower

Boxer,
I Don't know if select monitor will record the history your looking for a Laptop might be the best.
and I sure don't think there will be swift action on these issues Anywhere IMHO

Tony

 

One good friend had his checked his STI7UK PPP'd at Prodrive and P*ss Poor Performance was due to Fuel Pump, best friend has STi7UK has ocassional pinking (detting). 2 other friends have STi7'PPP with less than perfect performance. Mine has good days and bad ones
Had a Email from STI7EU non PPP with simular Power faults rectified wirh fuel pump.(1 from Japan and 1 far east) but don't know them. O/K not shed loads Lots of Peeps having strange inconsistant performance/Starting/pinking(Detting) issues and some engines gone POP( but it's a high powered engine so some will go Pop) Not putting all of these down to the Pump. Just pionting it out as a possibilty

Look through these five threads O/K most related to PPP but some Peeps have said maybe not PPP related but STi7 related.


Strange performnce of PPP


PPP Survey


STi7 Bang


Fuel Pump


Disavatages of PPP

Tony

Ps more info than on Watergate also not related to/work for/spokeman for Subaru

[Edited by T5NYW - 2/5/2003 8:52:34 PM]

 

Thanks Tony, that's my point - we're waiting for an official statement.....and action

Richard

[Edited by dowser - 2/5/2003 9:47:52 PM]