It Has been discussed before. Can you give me some feedback.
My MY01 used to do it slightly under partial acceleration when i fitted a ppp. Recently i added a full decat plus a wastegate and a pop off valve. The problem worsened.

Any solution or idea

Help appreciated

A.

 

why not buy a dawes to control the boost, £35...

Have you got a boost gauge so you can see whats happening with the boost...???

Dan

 

because I fooled the ecu with an electronic device. I wanted to know the possible causes before adding anything new.

However i want to install one gauge but i need one that fits the center console below the radio (MY01).
Any suggestions?

A.

 

nobody knows?

 

When you say boost fluctuations, do you mean overboost when turbo spools? If so, restrictor sizing seems to sort it for others.

Richard

 

Well, not exactly. I'm currently running higher boosts due to the full decat matched with a wastegate . When I tested i got in 3/4/5 gears 1.4 bar for 2 seconds (more or less depending on gear)@4000 rpm, 1.15 @ 6000 and 0.9@7000.
I fooled the ecu with a device that should have maintained the new parameters in storage in the Prodrive (PPP) ecu. So I took the device away to avoid having something visible in the bonnet. The CEL just came up 1000 km later.
In any case that shouldn't interfear with the problem i'm getting.
For boost fluctuation I mean a not homogeneous push when accelerating not at full trottle (usually 75%). In fact the car accelerates as if it has two different boost levels and keeps jumping between these two.

Do you knpw what can it be?

Help very much appreciated.

A.

 

ttt

 

Those 2 seconds or so of 1.4bar sound like overboost to me

 

Boost spiking..
Rob

 

"I fooled the ecu with a device that should have maintained the new parameters in storage in the Prodrive (PPP) ecu. So I took the device away to avoid having something visible in the bonnet. The CEL just came up 1000 km later."

Don't really understand this! Are you saying you fooled you're my01 PPP ecu and boost control was OK, but now you've taken this device off and boost control is rubbish (and you've now got a CEL)? What was the device - is it better when refitted?

And what's the CEL?

You can control the overshoot by changing the restrictor size - assuming the overshoot is caused by the breathing mods and not something the mysterious 'device' has done

Richard

 

well if it was overboost it would probably end up in fuel cut, don't you think?

 

Just because you are over boosint AFAIK doesn't mean that you will nit Fuel Cut.

CEL is Check Engine Light

 

Ian - I meant what is the CEL that's being stored in memory

Caronte - overboost is often a misused word. Overboost is just being above your boost target.....this may or may not lead to fuel cut, which is the head through the windscreen thing.

Don't know where fuel cut is on the my01>, but I haven't seen it on an STi7 overboosting to 1.7 bar

Richard

 

on MY01 should be @ 1.2 bar. fuel cut happens when you keep it at that level for a certain amount of seconds( don't kow how long). This device is built to make the ecu read a wrong value so that it thinks that you are running on its safety limits.

the problem is that also before the full decat (when I had only the PPP), it got the same problem even though less evident.

A.

 

But what error code is being stored as a result of the cel? Maybe better to return it to the dealer?

Richard

 

yes i need to check that first.

The problem is that i never have time to go to the dealer..so i thought somebody could have given me some advice.

Thank you all for your suggestions , I will keep you informed .

Andrea

 

Or you could join the black connectors....

Richard

 

what's that? short circuit? reset?

 

i just spoken with my mechanic in italy. the cel should be the lambda sensor misreading, but it has to be confirmed with a diagnosis. the fluctuation are likely to be wrong air /fuel ratio. in fact thatcould be a consecuence of a lean mixture.

let you know.

Andrea

 

The CEL is caused by the full decat and is due to the rear oxy sensor reading higher than it would with a cat, Scoobysport )and others) sell an electronic fix for this. It does not mean its failed.

You are suffering from boost "surge", this is due to the more open exhaust and induction making the turbo more lively, the ecu is mapped to take account of the std systems, change those over and the settings cannot hold boost under control ... classic problem.