gbrand Posted November 5, 2004 Share Posted November 5, 2004 91 legacy with the loping, dropping idle problem.(have kept up on older threads) Got much worse, and i cleaned the IAC with throttle body cleaner. made things worse. have checked TPS, plugs are good etc. I resprayed IAC with a spray lube (WD-40 imitation) and then got better-but not perfect. Could the issue be needs to be cleaned AND lubriicated to move freely agian? Quote Link to comment Share on other sites More sharing options...
gbrand Posted November 7, 2004 Author Share Posted November 7, 2004 OK, further diagnosis-after clearing codes/relearning sensors (thanks Josh for the instructions on your page) did get a 24 AIC code once. Car is better but still dies at stop sign sometimes after 20-30 seconds. My Chiltons diag test for sensor seems worthless. A) it calls for measuring sensor resistence between three terminals-while my harness has three terminals, my sensor actually only has 2(middle postion is empty- no pin). calls for measuring "resistence" in volts. Also voltage readings called for do not match what i am getting off car-so dont know if the car or the procedure is faulty. Anyway, my sensor is about 9 ohms between the 2 pins and infinite to ground. With IAC connected, Key on engine off I have approx zero volts to left and right pins on connctor(looking into IAC) and 12.5V on the center one(the one that does not connect to the IAC). When running I have about zero volts on the left pin and 2.2. to 4.1 on the right pin. I assume from reading this is prolly an "average" DC reading of a duty cycle (on and off) waveform. On AC volts I see a 6-8 volt component so that is good evidence of switching. I have not yet been able to see if the signal is present when the car dies. That is one of my next steps. New IAC is $238 or higher-am trying to avoid replacing if not the problem. Anyone carried the diagnosis down this path? And if you replaced the IAC, did it fix the problem-already saw one post wehre it did NOT-was the ECU. Thanks Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted November 8, 2004 Share Posted November 8, 2004 You've got the "crappier" style IAC valve The instructions in the chiltons is for the rotary one found on the autos. Subyluvr had some issues with his IAC, which is the same style you have. He replaced it and his problems went away. You may want to search through some of the posts on the legacycentral bbs www.bbs.legacycentral.org Quote Link to comment Share on other sites More sharing options...
WAWalker Posted November 8, 2004 Share Posted November 8, 2004 That IAC has to be completely dissasembled to clean. There are small air passages inside that get pluged with carbon and need to be cleaned out. It is easy to take apart. But BEWARE they are not easy to put back together. If I could figure out how to post pics here I would take one apart and get some pics for you. Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted November 9, 2004 Share Posted November 9, 2004 email me the pics, I'll host them and post..... jlegacy(at)surrealmirage.com Quote Link to comment Share on other sites More sharing options...
DerFahrer Posted November 9, 2004 Share Posted November 9, 2004 Yes I replaced my IAC valve and honestly, I think people jump on this too quickly. I tried disassembling mine and cleaning it, and majorly screwed up the whole thing. I bought a new valve for a cool $362 from the dealer out of necessity (FL is a Subaru desert). And to be honest, I've been having the same issues lately even since replacing the valve, so logic suggests that the valve may not be the culprit. Do realize, that the IAC valve is set from the factory much the same way as the various parts of the throttle body are, the stopscrews and the TPS sensor. The electrical part of the valve, held in by those two screws at the top, is set in that exact position from the factory. Removing that electrical part, unless you very accurately mark it, will cause you to permanently lose that setting, and your valve may never work right again. The only way I would service it (and I refuse to touch it now), is to spray brake (not carb, as that may gunk it up worse) cleaner into the main induction nipple that is fed by the intake hose, let it sit for a while for the cleaner to evaporate, and that's it. You really need to make 110% sure you have double-checked absolutely every other possibility for a poor idle before this. Check for vacuum leaks everywhere they are possible, check your O2 sensor, check the aforementioned settings of the throttle body to assure they haven't been tampered with, check your alternator, check your battery, everything. This may sound like overkill, but everything I just mentioned is far cheaper than the IAC valve. That is the last (and most expensive) resort. Quote Link to comment Share on other sites More sharing options...
WAWalker Posted November 9, 2004 Share Posted November 9, 2004 Josh, I don't have my digi cam w/ me today. I put your e-mail address in my address book. Will get some pic to you hopfully by the end of the week. Quote Link to comment Share on other sites More sharing options...
gbrand Posted November 11, 2004 Author Share Posted November 11, 2004 Drove car for a couple days now-only died once or twice, and no complaints from wife unit whose daily driver it is. Was in a lot more stop and go traffic than intended so got some good testing. Am going to leve it alone for now, unless (or until when) gets worse again. Will post any more news, good or bad. Quote Link to comment Share on other sites More sharing options...
WAWalker Posted November 11, 2004 Share Posted November 11, 2004 I emailed Legacy777 pics and a write up on cleaning the Hitachi IAC. Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted November 12, 2004 Share Posted November 12, 2004 I'm in seattle till monday. I won't get to post pics until I get back.....I'll have to resize them....they're a little big Quote Link to comment Share on other sites More sharing options...
WAWalker Posted November 12, 2004 Share Posted November 12, 2004 .....I'll have to resize them....they're a little big Is that why I can't seem to upload any pics to the Photo Gallery? Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted November 12, 2004 Share Posted November 12, 2004 It might be... You had like 7 pictures...give or take 2 or 3, and the email was like 9mb. Those are pretty big pictures. Quote Link to comment Share on other sites More sharing options...
jeatc Posted November 15, 2004 Share Posted November 15, 2004 I had the same problem. I tried adjusting the AIC position and this seemed to help a little but didn't totally eliminate the problem. I checked and cleaned everything. Then I heard a clicking sound coming from the PCV valve. I replaced the PVC valve and now it runs perfect. This may or may not solve your problem, but for about $5 it's worth a try. Quote Link to comment Share on other sites More sharing options...
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