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Old Aug 30, 2011 | 08:17 PM
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Default 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
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Old Aug 30, 2011 | 08:45 PM
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Have you had it mapped if yes was it rr not
Om road ?
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Old Aug 30, 2011 | 09:27 PM
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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?
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Old Aug 30, 2011 | 09:32 PM
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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
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Old Aug 30, 2011 | 09:49 PM
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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.
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Old Aug 30, 2011 | 10:50 PM
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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?
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Old Aug 30, 2011 | 10:57 PM
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The ecu is in the passenger footwell, right where your feet go (up and under the dash)

Tony
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Old Aug 30, 2011 | 11:35 PM
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ECU Info here http://www2.ecutek.com.au/ecu_original.htm
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Old Aug 30, 2011 | 11:53 PM
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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.
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Old Sep 2, 2011 | 08:22 PM
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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
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Old Sep 3, 2011 | 07:12 PM
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anyone got any ideas
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Old Sep 3, 2011 | 07:22 PM
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Have you reset the ecu?

Tony
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Old Sep 3, 2011 | 07:23 PM
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Yes reset ECU let it idle then took it for gentle drive, problem is still there!
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Old Sep 3, 2011 | 07:31 PM
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What fuel are you running?
Have you also replaced the MAF sensor?
Lambda could be at fault, you will need a dealer diagnostic machine to confirm though...

Tony
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Old Sep 3, 2011 | 07:31 PM
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Have you checked for fault codes on the ecu by plugging in the black connectors in the drivers foot well?
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Old Sep 3, 2011 | 07:37 PM
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Originally Posted by TonyBurns
What fuel are you running?
Have you also replaced the MAF sensor?
Lambda could be at fault, you will need a dealer diagnostic machine to confirm though...

Tony
MAF was replaced last March with a new dealer part. I always run on V power, or Tesco 99 nothing less.
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Old Sep 3, 2011 | 07:38 PM
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Originally Posted by winston69
Have you checked for fault codes on the ecu by plugging in the black connectors in the drivers foot well?
I dont get any. I just want to check anything thats likely to cause the issue before booking in garage
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Old Sep 3, 2011 | 07:51 PM
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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
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Old Sep 3, 2011 | 08:17 PM
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Originally Posted by TonyBurns
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
yes looks that way

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?
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Old Sep 3, 2011 | 08:31 PM
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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

Last edited by Gambit; Sep 3, 2011 at 08:33 PM.
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Old Sep 4, 2011 | 09:02 PM
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Originally Posted by Gambit
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
Thanks, yes cleaned boost solenoid. I will check lambda, if the garage tells me its lambda i will order from there.
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Old Sep 4, 2011 | 09:09 PM
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Mine had similar, 98 UK car, turned out to be one duff plug LEAD.
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Old Sep 4, 2011 | 09:17 PM
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i did look over the leads as mine are red, they was on the car when i bought it. Not sure if they are magnecor or similar.
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Old Sep 4, 2011 | 09:20 PM
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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

Last edited by Lettuce; Sep 4, 2011 at 09:21 PM.
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