Help with Hesitation
30 August 2011, 08:17 PM
#1
Help with Hesitation
Hi, My MY00 Uk turbo has a hesitation at 2500rpm, it happens mainly in 2nd and 3rd gear when i go to accelerate i can open the throttle fully but the car feels like its being stopped from revving for a second then goes.
Once on boost its fine all the way through the revs and is fine upto 2500rpm but its getting annoying.
I changed all the oil/filters/spark plugs (PFR6b)/fuel filter and cleaned the boost solenoid but its still there
. I have noticed the exhaust pops more than usual when cruising with no throttle could it be a fueling issue?
Only modifications to engine are Prodrive intercooler piping, cosworth panel filter and cobra back box
Any help/suggestions appreciated
Once on boost its fine all the way through the revs and is fine upto 2500rpm but its getting annoying.
I changed all the oil/filters/spark plugs (PFR6b)/fuel filter and cleaned the boost solenoid but its still there
. I have noticed the exhaust pops more than usual when cruising with no throttle could it be a fueling issue? Only modifications to engine are Prodrive intercooler piping, cosworth panel filter and cobra back box
Any help/suggestions appreciated
30 August 2011, 09:27 PM
#3
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sounds like a breathing problem, maybe the panel filter. i dont think you need to remap just because of a backbox, but i knows nothink me 
Have you checked pipe connection from the recirc valve? if you take it off and try to push the valve underneath it should be near impossible to do (but you can do it), if its pretty slack it might be that air is escaping and a replacement recirc with a better spring might sort it out. better still, if you can try it from a mate and just whittle the options down you'll get to the root cause.
Are your Engine management lights flashing on your display too?
Have you checked pipe connection from the recirc valve? if you take it off and try to push the valve underneath it should be near impossible to do (but you can do it), if its pretty slack it might be that air is escaping and a replacement recirc with a better spring might sort it out. better still, if you can try it from a mate and just whittle the options down you'll get to the root cause.
Are your Engine management lights flashing on your display too?
30 August 2011, 09:32 PM
#4
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It could be the MAF on its way out, you will notice more hesitation sometimes from that, but the standard ecu has its "emissions" mode which is around the same area (2.5k), im thinking try to reset the ecu first and see what happens then, if it improves then most likely a failing sensor (maf most likely).
Tony
Tony
30 August 2011, 09:49 PM
#5
Has it got the standard AE802 ECU? MY00 were well known for this and a lot of people swapped to the earlier ECU (AE800 or AE801). It made a big difference to my car.
30 August 2011, 10:50 PM
#6
Thanks for replies, The car is not remapped. I fitted an brand new MAF last january. I dont get any lights on dash and as i said it runs ok above and below 2500rpm. Its seems to happen more when using light throttle then going full throttle.
It did it with standard air filter so panel filter shouldn't be the cause. I will check recirc valve next.
Would lambda or fuel pump cause the issues described?
How do i find out ECU type? Its a standard My00 so will that be AE802?
It did it with standard air filter so panel filter shouldn't be the cause. I will check recirc valve next.
Would lambda or fuel pump cause the issues described?
How do i find out ECU type? Its a standard My00 so will that be AE802?
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30 August 2011, 11:35 PM
#8
30 August 2011, 11:53 PM
#9
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Hi,
I know the feeling...
My MY00 done it too. I changed MAF, coolant sensor, O2 sensor and more recently fuel pump & also fitted an alloy intercooler 'Y' pipe without joy - felt like I was
I changed my ECU to an AE801 (from AE802) and found that it's a lot better. Although it's still there, it's something I've learnt to live with/drive around now.
As the guys above mentioned it seems to be something to do with the emissions control (slow switching O2 sensor into closed/open loop I think I read) on 99/00 year cars - but more noticable on the '00.
I know the feeling...
My MY00 done it too. I changed MAF, coolant sensor, O2 sensor and more recently fuel pump & also fitted an alloy intercooler 'Y' pipe without joy - felt like I was
I changed my ECU to an AE801 (from AE802) and found that it's a lot better. Although it's still there, it's something I've learnt to live with/drive around now.
As the guys above mentioned it seems to be something to do with the emissions control (slow switching O2 sensor into closed/open loop I think I read
) on 99/00 year cars - but more noticable on the '00.
02 September 2011, 08:22 PM
#10
Right i took the car to work today, 80 mile drive to try and get a better idea of whats going on.
The issue is happening at around 2k rpm when cold and when upto temp it happens at any point between 2k rpm and 3k rpm. After 3k it boosts fine and pulls like normal.
If i accelerate then ease of and accelerate again in the 2-3k rpm range it hessitates for a second or two then goes.
I have had a quick look over all the pipework/boost solenoid/recirc valve etc and all looks ok. Ecu reset has not made any difference and still no lights on dash. The exaust does pop a lot when cruising off throttle at low revs is this normal for just a back box?
Its been fine for 18months so i dont think the ECU can be the issue
Would lambda cause these issues? Looking like a trip to subaru dealer
The issue is happening at around 2k rpm when cold and when upto temp it happens at any point between 2k rpm and 3k rpm. After 3k it boosts fine and pulls like normal.
If i accelerate then ease of and accelerate again in the 2-3k rpm range it hessitates for a second or two then goes.
I have had a quick look over all the pipework/boost solenoid/recirc valve etc and all looks ok. Ecu reset has not made any difference and still no lights on dash. The exaust does pop a lot when cruising off throttle at low revs is this normal for just a back box?
Its been fine for 18months so i dont think the ECU can be the issue
Would lambda cause these issues? Looking like a trip to subaru dealer
03 September 2011, 07:31 PM
#14
03 September 2011, 07:51 PM
#18
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off to the dealer then with their diagnostic equipment that can test the sensors, your probably going to have to replace that maf again, they do have a tendancy to go pop, and maybe the lambda too....
Tony
Tony
03 September 2011, 08:17 PM
#19
Sooner i can get simtek fitted the better
I know the MAF will be dealer only part but is there any where i can buy a cheap lambda from? i belive the standard one is bosch? most i have looked for seem to be listed as universal?
03 September 2011, 08:31 PM
#20
clean out the boost solenoid also, it gets gummed up with oil residue overtime and gives partial hestitation around 2-3k - but you've done this
changing Ypipe to ppp/sti also helped mine. but changing to the PPP ecu finally cured it
also, check if your lambda is a 3 or 4 wire. Bosch LS02 is the 3 wire and can be got from http://www.lambdasensor.com/ for £52 delivered. 4 wire might be the LS03 but check first
changing Ypipe to ppp/sti also helped mine. but changing to the PPP ecu finally cured it
also, check if your lambda is a 3 or 4 wire. Bosch LS02 is the 3 wire and can be got from http://www.lambdasensor.com/ for £52 delivered. 4 wire might be the LS03 but check first
Last edited by Gambit; 03 September 2011 at 08:33 PM.
04 September 2011, 09:02 PM
#21
clean out the boost solenoid also, it gets gummed up with oil residue overtime and gives partial hestitation around 2-3k - but you've done this
changing Ypipe to ppp/sti also helped mine. but changing to the PPP ecu finally cured it
also, check if your lambda is a 3 or 4 wire. Bosch LS02 is the 3 wire and can be got from http://www.lambdasensor.com/ for £52 delivered. 4 wire might be the LS03 but check first
changing Ypipe to ppp/sti also helped mine. but changing to the PPP ecu finally cured it
also, check if your lambda is a 3 or 4 wire. Bosch LS02 is the 3 wire and can be got from http://www.lambdasensor.com/ for £52 delivered. 4 wire might be the LS03 but check first
04 September 2011, 09:20 PM
#24
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Sounds like a similar problem im having with mine but from a standing start, thread here.....
https://www.scoobynet.com/general-te...ing-start.html
https://www.scoobynet.com/general-te...ing-start.html
Last edited by Lettuce; 04 September 2011 at 09:21 PM.
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