Puzzled by this lot!? Sti V3..............
08 February 2004, 05:17 PM
#1
Puzzled by this lot!? Sti V3..............
Hope this thread has the expert's attention!
Just changed the gearbox on my Sti V3 with AP clutch and all is ok....except now I have a very lumpy tickover from cold (or hot) and the tickover varies from 1500 to 800, sounds like there is someone in the car gently warming her up by brushing the throttle pedal. I've checked all the connections I've undone during the change of the box
The engine is standard except for a Magnex decat and a Blitz boost controller.
Engine sounds fine if you blip the throttle etc. Drives ok too!
My questions are:
Why should this happen when all I've done is change the box with the battery disconnected for about 5 weeks (I work slowly)
Is the MAF on it's way out?
Will a subaru Dealer 'find' a fault on their diagnostics for a Grey Import?
Any ideas guys?
Should I just not worry?
Just changed the gearbox on my Sti V3 with AP clutch and all is ok....except now I have a very lumpy tickover from cold (or hot) and the tickover varies from 1500 to 800, sounds like there is someone in the car gently warming her up by brushing the throttle pedal. I've checked all the connections I've undone during the change of the box
The engine is standard except for a Magnex decat and a Blitz boost controller.
Engine sounds fine if you blip the throttle etc. Drives ok too!
My questions are:
Why should this happen when all I've done is change the box with the battery disconnected for about 5 weeks (I work slowly)
Is the MAF on it's way out?
Will a subaru Dealer 'find' a fault on their diagnostics for a Grey Import?
Any ideas guys?
Should I just not worry?
08 February 2004, 05:53 PM
#3
Originally Posted by dowser
MAF and/or lambda (or, would be on a 99/00 car)....quite common after an ECU reset 
Richard
Richard
911
08 February 2004, 08:34 PM
#4
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If it's the MAF, replace before the first hill climb of the season - your ecu chooses load values based on MAF input, screwing fuelling (less) and timing (more)....
If it's the lambda, you can safely ignore.....but it'll be bunging in way too much fuel on closed loop....better to fix.
Best is to find someone with a similar car, and swap each in isolation (followed by an ECU reset) to identify which has failed. May also be necessary to clean the idle stepper motor. It may be both that need replacement.
Note: my experience with these issues is only really with my99-> cars. It *may* not be relevant for your earlier car
Richard
If it's the lambda, you can safely ignore.....but it'll be bunging in way too much fuel on closed loop....better to fix.
Best is to find someone with a similar car, and swap each in isolation (followed by an ECU reset) to identify which has failed. May also be necessary to clean the idle stepper motor. It may be both that need replacement.
Note: my experience with these issues is only really with my99-> cars. It *may* not be relevant for your earlier car
Richard
09 February 2004, 01:59 PM
#6
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A new MAF for a MY93 will cost you around £200 
Have you checked the idle control valve?
Had the same problem with my MY98, cleaning the MAF made a slight difference so i changed it and although it ran smoother i still got the idle hunt from time to time.
Couldn't figure out what it was. Other day checked to see what ECU is in my car and after taking the ECU out for an hour or so and fitting it back in the idle hunt has disapeared too.
I think what hapened was the MAF had learned the failing MAF reading and when fitting a new clutch hence disconecting the battery i had reset the ECU and the car ran rough due to the ECU not recognising the MAF readings. Then after fitting the new MAF i hadn't reset the ECU (although i thought i had)
To sumarise
it could be the MAF but make sure you reset the ECU
All the best
Franko
Have you checked the idle control valve?
Had the same problem with my MY98, cleaning the MAF made a slight difference so i changed it and although it ran smoother i still got the idle hunt from time to time.
Couldn't figure out what it was. Other day checked to see what ECU is in my car and after taking the ECU out for an hour or so and fitting it back in the idle hunt has disapeared too.
I think what hapened was the MAF had learned the failing MAF reading and when fitting a new clutch hence disconecting the battery i had reset the ECU and the car ran rough due to the ECU not recognising the MAF readings. Then after fitting the new MAF i hadn't reset the ECU (although i thought i had)
To sumarise
it could be the MAF but make sure you reset the ECU All the best
Franko
Last edited by Franko; 09 February 2004 at 01:59 PM.
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09 February 2004, 06:17 PM
#8
Wow, busy tonight!
Thanks for all the info. I did wrench around the dump valve hose area when fighting the gearbox.... Off with the TMIC again to realy check. Where is the idle sensor located?
Thanks guy, graham.
Thanks guy, graham.
09 February 2004, 08:59 PM
#9
10/10 for dela
Just taken the intake hose off the MAF and cleaned (drowned) it with brake cleaner. Looked pretty clean to me.
Removed the TMIC yet again to find the hose from the base of the dump valve broken off at the dump valve....just done a repair to prove a point. The pipe from the DV would be bleeding air straight into the inlet manifold which could explain the lumpy tick-over?
Have disconnected the battery for a few days to reset the ecu (long enough?) and for the araldite to set solid.
If it works then dela gets a Christmas card this year!
As ever, thanks chaps.
911
Removed the TMIC yet again to find the hose from the base of the dump valve broken off at the dump valve....just done a repair to prove a point. The pipe from the DV would be bleeding air straight into the inlet manifold which could explain the lumpy tick-over?
Have disconnected the battery for a few days to reset the ecu (long enough?) and for the araldite to set solid.
If it works then dela gets a Christmas card this year!
As ever, thanks chaps.
911
09 February 2004, 11:54 PM
#11
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911,
Sounds like you've cracked it. An ECU reset is easier done by using the plugs under the dash, but a day with the battery off will do it.
The 97/98 seems much less prone to MAF faults, and its normally the 02, ISCV or TPS that causes the problem.
MB
Sounds like you've cracked it. An ECU reset is easier done by using the plugs under the dash, but a day with the battery off will do it.
The 97/98 seems much less prone to MAF faults, and its normally the 02, ISCV or TPS that causes the problem.
MB
10 February 2004, 09:05 PM
#12
Job done!One smoooth runnin Sti...whew!
Originally Posted by Dark Blue Mark
911,
Sounds like you've cracked it. An ECU reset is easier done by using the plugs under the dash, but a day with the battery off will do it.
The 97/98 seems much less prone to MAF faults, and its normally the 02, ISCV or TPS that causes the problem.
MB
Sounds like you've cracked it. An ECU reset is easier done by using the plugs under the dash, but a day with the battery off will do it.
The 97/98 seems much less prone to MAF faults, and its normally the 02, ISCV or TPS that causes the problem.
MB
Also been offered a dump valve for the car as a spare!
Thanks to all, especially Dela.
Graham.
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