Catch22ska4 Posted November 3, 2008 Share Posted November 3, 2008 So, this isn't really another idle thread but... 1997 LGT Wagon A/T: I have noticed that when I hold my foot on the brake while at a stoplight, the car seems to be almost fighting me and in turn running really rough. With the foot on the brake, the car still wants to move forward (somewhat considerably or I wouldn't bother) and to stop the rough/bumping feeling I shift it into neutral until the light turns green. Anything I can do to fix this before it becomes worse? Thanks! Link to comment Share on other sites More sharing options...
jonklein611 Posted November 3, 2008 Share Posted November 3, 2008 check how tight your throttle cable is, might need loosen it Link to comment Share on other sites More sharing options...
Stang70Fastback Posted November 10, 2008 Share Posted November 10, 2008 I have the same problem! I've had it for a long time too. It feels as though the engine is pulling but it's idling at normal RPM. Usually it gets worse over a course of 10 seconds until the whole car is vibrating. I knock it into neutral and the revs go up a bit and then come back down. If I'm rolling at just like 2-3 mph it all but disappears. I always knock the car into neutral as I approach any stops - especially with someone in the car cause they get freaked out and it's embarrassing. How would I know if my throttle cable was too tight... and how would I loosen it? Lol. Link to comment Share on other sites More sharing options...
jonklein611 Posted November 10, 2008 Share Posted November 10, 2008 On the throttle body, there are two cables. Once is the cruise control, the other is from your gas pedal. Have one of your buddies push the throttle so you can see which is which. Check that cable when there is no foot on the gas, it should have a little bit of play in it. If it's taught, then it's possible that the throttle is open at idle. Simply losen the connection, give it a touch of slack, and then tighten everything back up. I can post a pic of what I'm talking about, but i'll have to dig my car out of the snow..... lol Link to comment Share on other sites More sharing options...
Stang70Fastback Posted November 10, 2008 Share Posted November 10, 2008 I know what the throttle body is, but I don't know where I would loosen it. Is there a nut on the throttle body itself that you just turn? Or is it more complicated than that? Link to comment Share on other sites More sharing options...
99SUS SFD Posted November 10, 2008 Share Posted November 10, 2008 Umm he said it. The cable for the throttle. Go open your hood and take a peek. Link to comment Share on other sites More sharing options...
Stang70Fastback Posted November 10, 2008 Share Posted November 10, 2008 I'll take a looksie. How would I tell if it's too tight? Cause I'd assume that even if it was, it would have some play. I guess if I touch it and the engine revs then it's likely a bit too tight? We'll see. Link to comment Share on other sites More sharing options...
jonklein611 Posted November 10, 2008 Share Posted November 10, 2008 I'll take a looksie. How would I tell if it's too tight? Cause I'd assume that even if it was, it would have some play. I guess if I touch it and the engine revs then it's likely a bit too tight? We'll see. Yeah, that means its too tight, you'll see some of the exposed cable, that shouldn't be super tight. Link to comment Share on other sites More sharing options...
Stang70Fastback Posted November 10, 2008 Share Posted November 10, 2008 Unfortunately, that's not the problem. There was definitely a bit of play in the throttle body before it would start pulling the wire. In fact, should there be play in it at all? I can wiggle it like 2mm back and forth before it tugs the wire. What else could be causing this? To me it feels as if the clutch isn't being completely disengaged when you come to a stop. The engine isn't idling and higher than it should be, but the whole car starts shuddering... and it seems as if there is pressure building up, cause when I knock it into neutral, and revs go up a few hundred and then settle back down. Link to comment Share on other sites More sharing options...
jonklein611 Posted November 10, 2008 Share Posted November 10, 2008 That amount of slack is good. What revs is it idling at in neutral and while in drive? Link to comment Share on other sites More sharing options...
Brewer Posted November 10, 2008 Share Posted November 10, 2008 Check for a leak post MAF. What are the RPMs when its happening? Link to comment Share on other sites More sharing options...
jonklein611 Posted November 10, 2008 Share Posted November 10, 2008 It does sound like some form of vacuum leak.... Link to comment Share on other sites More sharing options...
Stang70Fastback Posted November 11, 2008 Share Posted November 11, 2008 Well its dark and cold out now so I'm not gonna go and start it up and warm it up and everything now, but I'll check tomorrow. From memory, though, it idles somewhere around 5-800 RPM? Does that sound about right? How would I check for a leak and where? Do realize you're speaking to a mechanical know-nothing here, lol. I dunno if this is related... but: This is the car - I think I created a thread about this on this forum - with the stuttering problem that Subaru themselves couldn't diagnose. I don't know if the two are related. Both problems have gotten worse over recent months, but I can't remember if the car developed both issues at the same time. The stuttering happens under light (VERY LIGHT) throttle application after the car is warmed up - up to around 1500 RPM. It will basically almost stall, then pick up then stall then pick up (basically like an engine that really REALLY needs a tune-up). Idle's fine though, and drives fine - it's just light throttle up to 1500 RPM that causes it. Amazingly there is no CEL! Subaru has literally spent HOURS trying to diagnose it and all they did was replace one O2 sensor which did not fix the issue. Then they wanted to replace the other but at that point I just took the car back. Might be related... I dunno. I want to think they are NOT related... but I've no idea. Link to comment Share on other sites More sharing options...
jonklein611 Posted November 11, 2008 Share Posted November 11, 2008 Whens the last time you changed the plugs? Any mods done to the car? Your idle sounds correct for warm idle. Link to comment Share on other sites More sharing options...
Stang70Fastback Posted November 11, 2008 Share Posted November 11, 2008 No mods at ALL to the car other than the carputer setup. I actually did go out earlier. It idles around 600-700. What will happen is you'll come to a stop... and it will start shuddering... and it gets worse over like 10 seconds. When I take it out of drive into neutral, you hear the engine RPMs go up EVER so slightly and the needle moves like 25 RPM (so not really.) It's really just not disengaging something correctly I think. As for the stuttering, I would assume they tested to see if it was the plugs when they spent a few hours diagnosing the car, but who knows. It runs fine at any other RPM/throttle/speed, so it's just those low RPM, and since it's not throwing a code even though its close to stalling sometimes, I want to say it's not so much a mechanical problem as a sensor issue or something of that nature. I just can't understand how they couldn't figure it out. Link to comment Share on other sites More sharing options...
kingbobdole Posted November 11, 2008 Share Posted November 11, 2008 Plugs? check for a vac leak? (hissing noise) Idle Air Control motor clean? Link to comment Share on other sites More sharing options...
jonklein611 Posted November 11, 2008 Share Posted November 11, 2008 I've found that my AT shimmys and shakes at lights, but if i put it in neutral the shaking goes away. Drop it back into drive and things are much better. Doesn't sound like a vacuum leak (which would cause a higher idle). Could be your idle air control valve (IACV) or it could be something funky with the 4EAT. Link to comment Share on other sites More sharing options...
ConnertheCat Posted February 24, 2009 Share Posted February 24, 2009 On my 2000 AT GT I had that same problem, it ended up being dirty fuel injectors (that was one hell of a problem to track down too). Yeah, 3 months later but this info may be helpful to someone doing a search in the future. Link to comment Share on other sites More sharing options...
cman7 Posted February 25, 2009 Share Posted February 25, 2009 Wow. I'm glad to see someone else noticed this. I thought it was just me not being used to the auto. When I'm at stop lights it shudders and struggles to keep going....I really have to hold down the brake. I also noticed if you let the car roll forward slightly and then push the brake completely again it stops shuddering or if you put it in neutral It couldn't be the plugs as I just got them replaced a month ago with a full tuneup. I think it might be 4EAT specific. Link to comment Share on other sites More sharing options...
jonklein611 Posted February 27, 2009 Share Posted February 27, 2009 Or your throttle cable is too tight. Link to comment Share on other sites More sharing options...
cman7 Posted February 27, 2009 Share Posted February 27, 2009 Could be. I'll have to check later today when I check my oil. Link to comment Share on other sites More sharing options...
Stang70Fastback Posted February 27, 2009 Share Posted February 27, 2009 Same problem here, and throttle cable has a mm or two of play, so that's not it. Link to comment Share on other sites More sharing options...
Stang70Fastback Posted March 8, 2009 Share Posted March 8, 2009 Never REALLY paid attention, but noticed that when the car runs rough at the light, shuddering and everything, it's idling at about 800 rpm... ...when it isn't it's idling at closer to 600. Link to comment Share on other sites More sharing options...
ConnertheCat Posted March 8, 2009 Share Posted March 8, 2009 Wow. I'm glad to see someone else noticed this. I thought it was just me not being used to the auto. When I'm at stop lights it shudders and struggles to keep going....I really have to hold down the brake. I also noticed if you let the car roll forward slightly and then push the brake completely again it stops shuddering or if you put it in neutral It couldn't be the plugs as I just got them replaced a month ago with a full tuneup. I think it might be 4EAT specific. This is EXACTLY what my car was doing. I tried about everything - new plugs, cleaned the air intake, etc. Threw some fuel injector cleaner in the car, problem was gone (after having had it for like 5+ months)... I ended up frying my O2 sensors though... but that was an easy fix. I found that at rough idle it would struggle to keep the RPMs @ 600-800. It usually only happened when the car was just turned on (a few times it lasted longer, but yeah). My recommendation - spend the $4 and get some fuel injector cleaner (just get the right kind, as I did not...). Link to comment Share on other sites More sharing options...
levis76 Posted March 8, 2009 Share Posted March 8, 2009 Not to start a huge debate on it effectiveness, but wouldn't a healthy shot of SeaFoam in the tank clear this up if it is dirty injectors? Link to comment Share on other sites More sharing options...
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