Urgent help needed, car running like crap!!
Scooby Regular
Joined: Dec 2000
Posts: 2,912
Likes: 0
This looks well strange, considering you've changed:
* The exhaust
* The Lambda probe
* The ECU...Link?
The only thing you haven't changed looks to be the MAF sensor..but if the ECU you tried was a Possum Link (which doesn't use MAF at all)...
How much does it boost then? Peak/held?
This is very important, if it's boosting as it should I'd say there's summat fubar'd internally, otherwise it could be a silly thing like a leaking BOV or a wastegate that doesn't close properly...or even a shagged turbo.
Give us summat to work with mate.
Give my regards to Iles (I've got his old Link).
Cheers
/J
* The exhaust
* The Lambda probe
* The ECU...Link?
The only thing you haven't changed looks to be the MAF sensor..but if the ECU you tried was a Possum Link (which doesn't use MAF at all)...
How much does it boost then? Peak/held?
This is very important, if it's boosting as it should I'd say there's summat fubar'd internally, otherwise it could be a silly thing like a leaking BOV or a wastegate that doesn't close properly...or even a shagged turbo.
Give us summat to work with mate.
Give my regards to Iles (I've got his old Link).
Cheers
/J
Sponsor
Joined: Mar 1999
Posts: 3,938
Likes: 1
From: Swindon
Jerry I can just see a Subaru dealer fitting a Link (not), probably a PPP.
Maf would show on the select monitor, what wouldn't show is a faulty knock sensor or coolant temp sensor, both of those sensor's would cause the symptoms described. So wopuld a faulty crank position sensor come to that.
Only way to solve this sort of issue is to be methodical, change one thing at a time and revert it if it doesn't help, a dealer should be able to do that as they have access to all the sensors.
Maf would show on the select monitor, what wouldn't show is a faulty knock sensor or coolant temp sensor, both of those sensor's would cause the symptoms described. So wopuld a faulty crank position sensor come to that.
Only way to solve this sort of issue is to be methodical, change one thing at a time and revert it if it doesn't help, a dealer should be able to do that as they have access to all the sensors.
Scooby Regular
Joined: Aug 1999
Posts: 679
Likes: 0
Bob is right, the only way to diagnose this is to be methodical. Plug in a Select Monitor, drive and see if the figures *make sense*... the ECU may not necessarily regard a sensor as faulty if the readings are slghtly out! Most people who have ever played about with something like a MoTeC or Pectel will know what figures to expect, right down to injection pulse width (yep, you can get these figures from the SelectMonitor). Anything that looks odd can be traced back...
With regard to the all or nothing effect, it is possible that there is a fault with the knock sensor. If it is erroneously indicating knock when there is none, the ECU will retard the ignition timing (which will result in poor fuel economy and a high appearance AFR, plus fry the cat). When it has retarded the ignition as far as it can and it still is seeing knock then it will shutdown the boost control solenoid so you're back to 0.5 bar, the actuator pressure. If the fault is intermittent then the boost would come on and off as you describe...but this would be SOOOOO easy to spot on a SelectMonitor that any garage that doesn't needs to be shot!
As another side effect, the retarded ignition timing would increase the exhaust gas energy which will make the turbo want to spool quicker, quicker than perhaps the standard controls can catch it...
Of course there could be a hundred and one other reasons why it is happening.... the only real answer is to monitor everything, see what looks odd, then look at what could be causing it to go that way, sooner or later the answer will be found.
Hope this helps, and that you get it sorted Real Soon....
Cheers,
Pat.
With regard to the all or nothing effect, it is possible that there is a fault with the knock sensor. If it is erroneously indicating knock when there is none, the ECU will retard the ignition timing (which will result in poor fuel economy and a high appearance AFR, plus fry the cat). When it has retarded the ignition as far as it can and it still is seeing knock then it will shutdown the boost control solenoid so you're back to 0.5 bar, the actuator pressure. If the fault is intermittent then the boost would come on and off as you describe...but this would be SOOOOO easy to spot on a SelectMonitor that any garage that doesn't needs to be shot!
As another side effect, the retarded ignition timing would increase the exhaust gas energy which will make the turbo want to spool quicker, quicker than perhaps the standard controls can catch it...
Of course there could be a hundred and one other reasons why it is happening.... the only real answer is to monitor everything, see what looks odd, then look at what could be causing it to go that way, sooner or later the answer will be found.
Hope this helps, and that you get it sorted Real Soon....
Cheers,
Pat.
Trending Topics
Phil
If your car is not running well before the RR day, you may want to consider donating your place to me
After all your exhaust will invalidate your std reference status......
Just a thought!
Oh, nearly forgot to mention that if you don't get joy from your dealer with the clutch then try others in the surrounding area (don't mention that your dealer won't help of course). Especially if you need a service as the other dealer may help just to pick you up as a new service customer.
F
[Edited by Floyd - 10/18/2001 12:52:38 PM]
If your car is not running well before the RR day, you may want to consider donating your place to me
After all your exhaust will invalidate your std reference status......
Just a thought!
Oh, nearly forgot to mention that if you don't get joy from your dealer with the clutch then try others in the surrounding area (don't mention that your dealer won't help of course). Especially if you need a service as the other dealer may help just to pick you up as a new service customer.
F
[Edited by Floyd - 10/18/2001 12:52:38 PM]
Thread Starter
Scooby Regular
Joined: Feb 2001
Posts: 4,370
Likes: 0
Floyd,
Yes agreed, I have the decat'ed downpipe so I guess my place is up for grabs now. You better speak to David Taylor, or chins to confirm, there could have been someone on the list before you.
Pat,
Picked it up just now from having the clutch and all the rest looked at and it's the same flat (no real power) They didn't change the knock sensor though. They told me that they changed the restrictor and it has been fine since. I disagree!!! The Lamba sensor was changed as they broke the thread taking it out.
Not happy, cheers Phill C
Yes agreed, I have the decat'ed downpipe so I guess my place is up for grabs now. You better speak to David Taylor, or chins to confirm, there could have been someone on the list before you.
Pat,
Picked it up just now from having the clutch and all the rest looked at and it's the same flat (no real power) They didn't change the knock sensor though. They told me that they changed the restrictor and it has been fine since. I disagree!!! The Lamba sensor was changed as they broke the thread taking it out.
Not happy, cheers Phill C
Thread
Thread Starter
Forum
Replies
Last Post
ossett2k2
Engine Management and ECU Remapping
15
Sep 23, 2015 09:11 AM