serious overboost problem
15 January 2005, 08:04 PM
#1
Scooby Regular
Thread Starter
Join Date: May 2003
Posts: 265
Likes: 0
Received 0 Likes
on
0 Posts
serious overboost problem
The car is a STI 3 running full decat system and green panel filter
The only thing i have to go on is a sh#~y blitz turbo timer that tells boost pressure, and records the max pressure hit, and the fact that the car hits fuel cut!- big time!!!!
You prob wont beleive this but its saying that the max boost is 22psi
What the hell can be causing this???????
Whiteknight
The only thing i have to go on is a sh#~y blitz turbo timer that tells boost pressure, and records the max pressure hit, and the fact that the car hits fuel cut!- big time!!!!
You prob wont beleive this but its saying that the max boost is 22psi
What the hell can be causing this???????
Whiteknight
15 January 2005, 10:46 PM
#3
Scooby Regular
Thread Starter
Join Date: May 2003
Posts: 265
Likes: 0
Received 0 Likes
on
0 Posts
i was at tsl on friday and mentioned the problem, they found a small split in one of the hoses and replaced and said that it should be sorted, so on the way home i did the 40 mph 5th gear acceleration test, and bang fuel cut whiplash!
it only usually happens in 5th
it only usually happens in 5th
18 January 2005, 10:34 PM
#5
Scooby Regular
Join Date: Nov 2004
Location: lake district
Posts: 212
Likes: 0
Received 0 Likes
on
0 Posts
What has ur max boost been since they replaced that faulty pipe, reset ur max boost reading to zero, then do same 5th gear test again.
I'm thinking that it must be boosting just shy of whatever psi the v3 gets fuel cut at, 16 18 psi cant remember off hand, anyway if its only happening in 5th its only under really heavy load conditions so it must be well close to cut in lower gears, this makes me think its been set like that. and the only reason you had a reading of 22psi previous is cos of that split pipe.
Would really help if you had an analogue boost gauge, but seen you have'nt, it would help to know,
has the car always done this or has it just started happening?
Max boost recorded since pipe fix?
Do you have any sort of aftermarket boost controller fitted?
Is the ecu standard?
I'm thinking that it must be boosting just shy of whatever psi the v3 gets fuel cut at, 16 18 psi cant remember off hand, anyway if its only happening in 5th its only under really heavy load conditions so it must be well close to cut in lower gears, this makes me think its been set like that. and the only reason you had a reading of 22psi previous is cos of that split pipe.
Would really help if you had an analogue boost gauge, but seen you have'nt, it would help to know,
has the car always done this or has it just started happening?
Max boost recorded since pipe fix?
Do you have any sort of aftermarket boost controller fitted?
Is the ecu standard?
19 January 2005, 06:42 AM
#6
3years ago I had this issue but more acutely!
Sti v3, full decat, green filter = freer flowing engine.
Except in 1st, precisely at 4250 rpm full throttle BANG, in any gear; ease the throttle back and the car ran through the same spot perfectly (and not much slower).
I tried all the usual solenoid things/pipes and voodoo charms to no avail.
Took it to Power Engineering in London who checked it on their RR.
The car was hitting 1.6 bar at cut! (no wonder it went well...)
They fitted a Blitz Boost controller, set it at 1.25 bar and it RR'd @ 314 bhp on Optimax.
The display soon crept to 1.31 bar and has been there for 2 years now.
I drive 3000 road miles and seriously compete in the car and I have NEVER had a fuel cut problem since no matter what.
I have never changed the setting or messed with it incase it came back.
Some v3 ecu's are unstable to the fuel cut trigger point where boost level cannot be tolerated. My problem started about 3 months after fitting the Magnex exhaust.
Maybe this helps,
911
Sti v3, full decat, green filter = freer flowing engine.
Except in 1st, precisely at 4250 rpm full throttle BANG, in any gear; ease the throttle back and the car ran through the same spot perfectly (and not much slower).
I tried all the usual solenoid things/pipes and voodoo charms to no avail.
Took it to Power Engineering in London who checked it on their RR.
The car was hitting 1.6 bar at cut! (no wonder it went well...)
They fitted a Blitz Boost controller, set it at 1.25 bar and it RR'd @ 314 bhp on Optimax.
The display soon crept to 1.31 bar and has been there for 2 years now.
I drive 3000 road miles and seriously compete in the car and I have NEVER had a fuel cut problem since no matter what.
I have never changed the setting or messed with it incase it came back.
Some v3 ecu's are unstable to the fuel cut trigger point where boost level cannot be tolerated. My problem started about 3 months after fitting the Magnex exhaust.
Maybe this helps,
911
Last edited by 911; 19 January 2005 at 06:44 AM. Reason: spelling again...
Thread
Thread Starter
Forum
Replies
Last Post