Boost fluctuations
07 October 2002, 07:10 PM
#1
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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.
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.
08 October 2002, 12:03 AM
#3
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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.
However i want to install one gauge but i need one that fits the center console below the radio (MY01).
Any suggestions?
A.
09 October 2002, 11:34 PM
#6
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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.
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.
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11 October 2002, 08:40 AM
#10
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"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
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
11 October 2002, 02:05 PM
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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
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
11 October 2002, 04:26 PM
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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.
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.
11 October 2002, 04:52 PM
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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
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
11 October 2002, 06:32 PM
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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
let you know.
Andrea
11 October 2002, 11:31 PM
#20
Ecu Specialist
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.
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.
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