ericem Posted April 17, 2007 Share Posted April 17, 2007 1. Tried seafoam, no difference(through PCV) 2. fuel injection cleaner in the tank, no difference 3. wipe throtle body and spray throttle body cleaner VERY heavily in the throttle body, pretty much eliminated rough idle SO this seems to be the best way to fix rough idle. 4. sprayed maf sensor with cleaner, not VERY noticeable but fuel economy seems better ill see next fill up. Now im experimenting with the voltage im getting at idle. when i turn on my lights while im in Park, the rpms drop ever so slightly and the engine rumbles a bit, turn off lights, engine is smooth and idle came up a tiny bit. So now im going to look into new ground cables as the alternator is pushing 14.4v. AFAIK I also have a cracked knock sensor no CEL though, so after i get the new sensor this week ill report on whether it makes it more smoother then it is. Just thought id share. tested on my 93 legacy NON turbo Wagon L. with 190k(about 292,000KM) Quote Link to comment Share on other sites More sharing options...
Manarius Posted April 17, 2007 Share Posted April 17, 2007 Define rough idle. I'd like to know what you define as rough because the rest of us might call it normal. Quote Link to comment Share on other sites More sharing options...
Bmm001 Posted April 17, 2007 Share Posted April 17, 2007 Have you checked all the hoses? Could be a vaccuum leak... Brian Quote Link to comment Share on other sites More sharing options...
ericem Posted April 17, 2007 Author Share Posted April 17, 2007 i consider rough when i can feel idle at all :-p But after i cleaned the throttle body its pretty much can't feel idle at all. Not shaking like its going to die. Quote Link to comment Share on other sites More sharing options...
ericem Posted April 18, 2007 Author Share Posted April 18, 2007 replaced the knock sensor, so far the car is amazing now. And idle is very consistant. Quote Link to comment Share on other sites More sharing options...
wtdash Posted April 19, 2007 Share Posted April 19, 2007 I have a '90 Legacy...did you have any surging in RPM? Mine does when it's started when warm - not a cold start. Goes up and down from 1200 RPM to 500-ish for about 10-15 seconds. Otherwise car idles no worse than any other Sube I've had....like Manarius said, I consider it the Subie rumble. Quote Link to comment Share on other sites More sharing options...
ericem Posted April 19, 2007 Author Share Posted April 19, 2007 ya, its really weird the way these cars rumble, every other car i have been in has never vibrated like these cars. When i feel like it im going to change my tranny mount, in hopes that it makes it idle even better. Now im hoping to get MUCH better fuel economy with the new knock sensor. Quote Link to comment Share on other sites More sharing options...
Jutboy Posted May 9, 2007 Share Posted May 9, 2007 I have this same problem on my 91 Legacy SS Can explain how you get the trottle body cleaner in the throttle body....sorry I haven't done any throttle body work at all so I'm pretty clueless (pics would be appreciated). THANKS ALOT - Justin Quote Link to comment Share on other sites More sharing options...
ericem Posted May 9, 2007 Author Share Posted May 9, 2007 Ill take pics of what you need to remove later. Kind of busy. Quote Link to comment Share on other sites More sharing options...
ericem Posted May 9, 2007 Author Share Posted May 9, 2007 Just remove the black intake hose, so loosen the clamp with the screw very simple. Oh and there are a few hoes attached at the bottom of the intake, so just unplug them they are held on with butterfly clips. I think just 1 needed to be removed, nothing difficult. Then once you get the intake out of the way doesn't need to come out, spray ALOT of throttle body cleaner inside, i sprayed it, then wiped with a paper towel, however a lint free cloth is a better idea, then just push to open throttle and get inbetween the throttle piece, and get around the top, i just sprayed heavily and it broke away whatever was building up. If this doesn't help much, i suggest new plugs and wires. Quote Link to comment Share on other sites More sharing options...
Jutboy Posted May 10, 2007 Share Posted May 10, 2007 so you don't need to take the whole throttle assembly off...you can just pop of the intake tube and work on it from that opening...I assume the cleaner doesn't matter if it gets into engine but what about all the junk that gets cleaned off? Thanks a lot for the help - good pictures too ! Justin Quote Link to comment Share on other sites More sharing options...
ericem Posted May 10, 2007 Author Share Posted May 10, 2007 Nope should not matter it just burns it once you start the engine you might need to give it a little bit off gas starting it after throwing all that throttle body cleaner in the engine, when i did it there was alot of gray smoke once it started. I don't think its debris building up, i think its just oil's or grease. Quote Link to comment Share on other sites More sharing options...
Manarius Posted May 10, 2007 Share Posted May 10, 2007 I still think Seafoam through the PCV and gas will work best. Then you can use throttle body cleaner if you want (don't wipe it out, it's probably just ether anyways). I did notice a small bit of overall smoothness increase when I ran Seafoam through the PCV valve last year. My car's 16 years old, I don't expect it to idle extremely smooth. At the same time, I would notice if it was idling abnormally. My car doesn't shake at all when it idles, even though it idles (when warm) sub-500rpm. Quote Link to comment Share on other sites More sharing options...
ericem Posted May 10, 2007 Author Share Posted May 10, 2007 Oh ya i ran the seafoam to through the PCV valve, made a difference but not a wow difference. Quote Link to comment Share on other sites More sharing options...
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