greg davis Posted October 7, 2004 Share Posted October 7, 2004 The slight shudder under acceleration was noticable on the LGT 5M i test drove, it was in no way as noticible as on my '02 WRX. A manual trans car will reflect more driveline feedback than auto car. My WRX is fine while in the open loop mode but as soon as the car goes to closed loop it appears. It is an ECU and/or sensor problem, thats why some may have sucess with the grounding mod beleiving a sensor is being read incorectly. Since the Cobb reflash takes care of this with a more aggressive closed loop tuning could it be that Subaru is trying to be to conservative, you have to figure that the engineers beleive someone will be using 87 octane or lugging the engine and they have to safeguard against that so as the knock sensor is set way to sensitive. This shudder is the same feeling as when the timing is being retrded then advanced again as knock goes away even though typically the delay to get advance back is time delayed and this shudder is a bit to quick at compaired to older pre OBDII ECU. Cant the service tech watch such parameters live as it is being driven? The ECU is "learning" is the biggest line of BS ever! It is not a turbo car "thing" either, I have had and still do have other makes of turbo cars. Link to comment Share on other sites More sharing options...
canis Posted October 7, 2004 Share Posted October 7, 2004 Well mine did it, and after 1,600 miles it still does occasionally, though it's not as noticeable. Anyway, I went on a drive with a Subaru Tech while I was at the dealership the other day. Naturally I couldn't get it to reproduce very well (slightly, but not as blatant as it sometimes is). Nonetheless, he researched it and said Subaru has nothing on it. He also spoke with his district manager who also was unaware of the problem. But they appear to be taking it seriously - the district manager suggested the two of them test drive a couple new cars off the lot. Anyway, I printed off all seven pages of this thread and gave it to him so he'll know it's not just me. He was actually very appreciative, saying that the more people with the same problem, the more expedient Subaru will be to fix it! So go to the dealer! Link to comment Share on other sites More sharing options...
Boostjunkie Posted October 9, 2004 Share Posted October 9, 2004 Well, I was just at my local dealer for an alignment issue (whole 'nother story there) and I spoke to a tech about the stuttering. He gave me a look of knowing resignation. Basically said that he and SOA know of it but there is nothing that can be done about it right now. He mentioned that the STi had problems with pinging when they first came out, and that SOA took a year to come up with a revised ECU program to solve the problem. I'm in CA, where we are stuck with crappy 91 octane gas, and I'm sure if the ECU's timing curve is little too aggressive it would cause the car to ping and the ECU to pull timing, thus causing the stumbling sensation. I'm sure there is more to it than that too, but who knows. At least I was planning on a reflash anyways, so it doesn't concern me that much, but it is still a little disappointing. Link to comment Share on other sites More sharing options...
Deer Killer Posted October 9, 2004 Share Posted October 9, 2004 93 octane has the same results.. However I've noticed (subjectively) that Shell 93 (V-power) makes it much worse than Exxon 93. Link to comment Share on other sites More sharing options...
Guest *Jedimaster* Posted October 9, 2004 Share Posted October 9, 2004 93 octane here too. And still the stuttering. Sucks that Subaru will take a year to come up with a fix- COBB will have their reflash done well before then. Link to comment Share on other sites More sharing options...
emlevins Posted October 12, 2004 Share Posted October 12, 2004 Well, I have it too...at 1K miles, though it has been apparent for awhile. Just posted on it elsewhere because i missed this thread and a knowledgeable user (Rouge) directed me here. At least, I know I'm not alone. Little consolation but consolation none the less. 05 SWP Legacy GT Limited (aka "Pearl")- 5MT AP - Stage 2 Protuned (238/284) - wife driven 07 BMW 335xi Link to comment Share on other sites More sharing options...
cgardner Posted October 12, 2004 Share Posted October 12, 2004 I test drove two cars at different dealers. I immediately noticed the "hesitation" when the dealer was driving it to get gas, and it was painfully obvious when I took the wheel. I went to a second dealership the next day to drive another car, just to make sure I wasn't crazy. That car did it too. You can even see the tachometer hesitate as it sweeps up. Pre-boost hesitation and stumble (1500-3000 rpms or so). Absolutely repeatable. Feels like the ECU is pulling back on the timing or something. I jumped on the boards to see if anyone had seen the same thing and lo and behold... I was going to buy the car this week, red (!) GT LTD with taupe. Not now. I am sitting this one out until I see a fix. Link to comment Share on other sites More sharing options...
MDTURBO Posted June 7, 2005 Share Posted June 7, 2005 I'm going to go out on a limb and say it's the tgv system. Maybe the valves open at 2500 and cause a lean condition? or it's a stock ecu tuning issue. 2012 Forester XT. Stage 2+ Retired from Racing. I used to build FMIC and more. Link to comment Share on other sites More sharing options...
DKB_SATX Posted June 10, 2005 Share Posted June 10, 2005 Has ANYONE resolved this issue? As seems the usual, my dealer "couldn't reproduce" the problem when I had the car in for the 3000 mile service. I'm going to to take the service writer for a ride next time around, since I can reproduce the problem reliably. Also, the service writer claimed that Subaru hadn't heard of the problem... still standard stuff. So, I have the hesitation problem and the dealer-doesn't-understand problem. *sigh* DKB Link to comment Share on other sites More sharing options...
ken_depew Posted June 24, 2005 Share Posted June 24, 2005 Iam going to tell you guys that I tried this from another post and it seems to work try it.I pulled the neg side of the battery cable off and stepped on the brake until no lights or power about 5 times and this resets the ecu and the car learns all over again.I have 6500 miles and always had the studder bad but it has almost gone away completely. Link to comment Share on other sites More sharing options...
ken_depew Posted June 24, 2005 Share Posted June 24, 2005 Also I fuse box under hood pull ecu fuse and that also should work. Link to comment Share on other sites More sharing options...
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