Could anyone shed any light upon this... UK MY00, standard except ITG panel filter:

Car seems to behave as expected (comparing to a UK 98) until it hits 3.5k revs. Power comes in but then seems to hesitate briefly @ 3.5 and then continues on through the revs range. This was mostly noticable in 3rd gear.

Could this be down to the much discussed MAF problems related to the later classics running ITG filters?? .....intercooler has excessive damage too the fins as well - doubt that is relevant though?

Steve

 

Has it always done it, or has it just started?

Certainly could be related to MAF damage (either due to ITG gunk contamination or simple wear). If it's always done it, it could simply be another case of MY00 ECU syndrome.

Damaged I/C fins might not be relevant to this problem, but it certainly doesn't help your engine, BTW. If they're just bent, get a cocktail stick or similar and spend an hour or two straightening them.

 

3rd gear is the first one where you're likely to get full boost & acceleration is the most obvious, which might explain that bit...
But I'd think of the MAF. Try resetting the ECU - if the idle starts to, well, not idle very well, it's likely your MAF is on the way out & the ECU will be underfuelling - not good! In this situation the MAF should be replaced (~£80 if the garage has any sense). If you ask them for the MAF sensor & they want to check yours, they will say it's fine - it's not, they just don't have the means to test it properly

 

Thanks for the replys

Regarding the history of the problem - I dont know as I was test driving the car for a friend who was interested in buying it (Private so not so easy to get it checked as if it was a dealer). Comparing it to my 98, something noticable happens at 3.5k - Nom you are correct in saying 3rd gear would highlight this as I didnt want to rag someone elses car in 2nd to see if it was the same

Greasemonkey - thanks, could you explain MY00 ECU syndrome please ? - sound like it could be useful info.

Due to possible MAF problem - would you suggest walking away from this car incase it has further related problems in the future (I can guide my mate - but I am not THAT technical)

Thanks for your help
Steve

 

MY00 syndrome is nothing more than the MY00 AE802 ECU being a bit "soft". Not only does it produce less power than the otherwise identical MY99 installations (while also producing worse fuel economy!), it has a reputation for causing hesitancy and bad throttle response.

If the car is otherwise in good nick, it can be remedied easily enough by dropping in a secondhand MY99 AE801 or AE800 ECU - or of course a TeK of some description.

As far as walking away is concerned, it's always impossible to comment on these things without actually seeing the car. If I had to guess (and if you read my posts a lot you'll know that I don't like guessing), I'd say what you experienced is more likely to be MY00 ECU syndrome rather than anything else, but of course if it's a private sale it's always better to be safe than sorry. How long's the ITG filter been in?

 

Greasemonkey - excellent info , thanks. I didnt know there was a different ECU between the 99, 00 cars. What you say about ‘poor throttle response’ ties in with what the owner was saying..... he mentioned a known problem which he sometimes gets in second gear where full boost is not achieved until you lift off to half throttle, and then full throttle (or something similar to that sequence).

Car is in very good condition otherwise (Except intercooler as mentioned) - only has 24k with full history. I think the filter has been in for about half the milage.

Unless someone else comes along to buy, the seller did seem happy to get a Subaru specialist to do a test drive whilst doing the MOT for a more knowledgable opinion to myself. Good to be armed with more info though incase a discussion occurs with the techie

Thanks, Steve

 

Hanging around at 40mph & flooring it will always give a bad response - drive-by regs dictate that to pass the noise level test, only half boost can be used, so things will be a bit pants. But the car's meant to do it - not too handy as it's about typical 'starting' overtaking speeds, so you stay on the wrong side of the road for longer.
Nice safety feature

 

Just to throw a bit more in about the MY00 ECU Syndrome.

I've got an MY00 Wagon, this has this same hesitancy at about the 3,500rpm mark and as you say it is by far most noticeable in 3rd and only when light throttle is applied.

Although everyone says, it's normal, it's the MY00 ECU, I'm not so convinced, I've had the car since 24k miles and now she's about to hit 32k and I'm almost positive it hasn't always done it.

I don't believe that this is MAF related, as I'm reasonably confident that the MAF is ok in her, and besides, 3,500 rpm light throttle surely this is closed loop mode? My money's on the Lambda, this I do believe is in need of replacement, not only given the mileage (32k) but also I'm not convinced that the fuel economy is quite up to what it should be. Besides anything else, we're all aware of the 'over fueling' associated with the MY00 ECU, a fooked lambda will just take this that little bit too far.

I haven't got round to changing it yet to see. I have bought 2 lambdas, one's already been fitted to the RA (Fuel economy has been instantly improved), but I managed to get copper ease in the other, so I'm not sure whether it's gonna be ok anymore or whether it's dustbin fodder?

 

Mine does it at ~2800 rpm with light throttle and steady speed.
It doesn't do it under any other conditions, but is noticeable in 1st - 4th gear.
An open throttle produces smooth acceleration, well no hesitation at least

I had assumed it was the ECU map, as it feels like the engine is oscillating either side of some balance point. Almost like the ECU keeps cutting the fuel to maintain the constant speed/rpm.

Looking at the standard 802 map doesn't show any huge jump at that rpm though.

The point about the Lambda is interesting. I was getting around 300 miles out of a tank and am now getting 260-280.
It could be the fact it's winter, with wet, slippery roads or I suppose it could be me getting more used to the car.
I'm not particularly light on the throttle, I just have a steady but busy run into work
Still fun in the scoob though

 

Mine's gone down from as much as 240 miles per tank, down to about 210 and I don't think I'm booting her nufin as like as much as I did when I first got her. (this also corrolates with the apparision of the hesitation)

The RA (MY99) before lambda change was looking like she woz gonna do about 170 on a tank, since the change in Lambda the fuel guage hasn't gone down anything like as quick and I reckon I'll be getting over 200 now This also had suffered from hesitation at various points in it's low end rev range although to a much worser degree than the MY00 Wagon.