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Old 07-27-2005, 10:28 PM   #1
bugman1964
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Subaru Stars Rough Idle

While tuning the E Manage car started to idle rough and misfire at idle. Any changes on the e manage don't seem to help. Car will only stay running with slight throttle. Tried removin the Idle air valve and cleaned it out. narrow band o2 sensor seems to be reading ok. has new plugs and wires 100 miles ago. Any ideas?? EJ20G motor with EJ22T heads, EJ18 ECU.
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Old 07-28-2005, 02:28 AM   #2
Aus_RS
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Heated or non-heated narrowband O2? If it's not heated, then you can't really trust what's it's saying. If you're running super rich, the exhaust might not even get the sensor hot enough to be in the operating range. My experience with non-heated narrowband was always that the reading difference between stoch. and rich (at idle) wasn't all that much.
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Old 07-29-2005, 02:55 AM   #3
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it is a heated o2 sensor. but i dont think its the o2.. is there a way to test the iac?
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Old 07-29-2005, 03:44 AM   #4
reddevil
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Plug wires! Stupid idea but often right!
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Old 07-29-2005, 11:03 AM   #5
Matt Monson
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Jacob,
What RPM is the car idling at. I am still thinking along the same lines as Paul, that the throttle cable adjustment may be off.
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Old 07-29-2005, 12:11 PM   #6
blaznc
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Check and make sure all your injectors are plugged in and functioning. I was running on three once upon a time because the injector harnesses weren't spliced correctly....
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Old 07-29-2005, 01:35 PM   #7
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also - make sure you don't have the anti engine stall map turned on. If unconfigured it will the car to idle poorly and most likely stall everywhere.

Todd
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Old 07-29-2005, 08:16 PM   #8
bugman1964
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humm hitokiri thats an interesting thought i think i have it turned on on my car. cause its not so much a rough idle as much as when i take my foot off the accelorator it stalls. As far as the throttle cable im gonna try to tighten it tonight but it feels tight.
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Old 07-29-2005, 10:31 PM   #9
bugman1964
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well i took off the anti stall that made it a bit better but it still wont idle i even tried cranking up the throttle cable some times it holds it some times it doesnt.
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Old 07-30-2005, 11:55 AM   #10
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I had a bad vacuum leak that did that to my car.
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Old 07-30-2005, 02:21 PM   #11
bugman1964
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yeah i was just talking to subachad and that was his thinking and mine as well with all my other symptoms.. now i just have to figure out all my vaccum hoses and try to find it.
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Old 07-30-2005, 03:51 PM   #12
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What injectors are you running?

I have the 370's in mine and at idle I'm still too rich. I need to mess with the E-manage a little more to get the idle right. I found this out drag racing. When the car idles too long it fouls out the plugs because its so rich. Once the plugs go, it doesn't idle well.

On the plus side, I'm safely running 11psi.

Chad
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Old 07-31-2005, 02:20 PM   #13
bugman1964
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yeah im runnign the 370's as well maybe ill pull the plugs and check them again but i didnt think it would be that bad this fast since its only been150 miles since i put new plugs in.
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Old 07-31-2005, 02:57 PM   #14
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When did the problem start, when you plugged in emanage?

People will suggest you just start replacing parts, this is the most expensive way to fix this problem. How about some rational thinking and diagnostic steps?

1. Did the car ever run well? if so what changed?
2. If emanage was the last step, check your settings. Having selected the wrong jumper will calibrate emanage for a different type of maf/map sensor and will cause an extreme rough runability/idle.
3. Check spark plugs, are they gassy or white? gassy=too rich, white=too lean.
4. 02 sensor is not used to trim fuel at idle, this is only used for cruising, so a bad o2 sensor is probably not the cause of idle problems.
5. IAC motor can cause rough idle. You should not have to adjust it whatsoever. One way of 'testing it' is tapping it with a hammer/socket extension. If its stuck on a bad winding, this can jolt it. However, this doesnt always work, and if you do it too hard, you could break it.
6. Consider major causes of bad idle:
a. spark wires arcing to ground: let the car idle and spray the wires with a spray water bottle. If you see 'lightning' from the wires, you will know they are bad.
b. bad spark plugs, pull them out, inspect. check for color and gap.
c. bad coil. pull spark plug wires off entirely (w/ car off) turn engine over with key, have someone watch, they should spark to the intake manifold.
d. fuel. are you sure these injectors work? 370cc legacy injectors are very old at this point. you can ohm check them, tehy should all be about the same. you can also disconnect each one individually while the car is running, if one is not firing, you wont notice any difference when you disconnect it.
e. vacuum leak, if you have ANY hoses disconnected, or a leaking ATM BOV, it will cause this. Use propane or (carefully) use carb clean and spray around intake and intake manifold while idling, if idle raises at all, you have a vacuum leak.

-Jake

btw, this crap took a long time to write, i hope you read these because this is actual diagnostic steps, not just random thoughts like many people have given you.
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Old 08-01-2005, 01:14 PM   #15
bugman1964
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thanks for your response unsung boxer. the car was idling all be it rough but after one day meesing with the tuning on the emange it just stopped iddling.we reverted all settings to no availe. i have tried most of your above diag tips/tricks,the only thing really left to do is check the plugs again and recheck for a vaccum leak. all thought ive tried using brake clean 3 times ot find a leak to no avail. i am starting to lean towards a bad iac due to when we pulled it out it was all carboned up. we cleaned it but it didnt have any relevance to fixing it.
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Old 08-01-2005, 02:26 PM   #16
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Jake, My thoughts weren't random. I'm having similar issues. I still think I have a bad IAC but that's only part of the idle problem. Just after installing the 370cc injectors, the plugs fouled super quick. Realize we are going from 220cc to 370cc injectors which is a huge step.

I notice if I let the car idle for a long time it seems to foul out the plugs. Pulling them reveils some gassy wet plugs. I also think a little more tuning with the emanage will help the rich idle mixture.

Bugman, send me your email address again so I can email my new maps to you. I'm now safely at 11psi though the timing portion of my tune is not quite as tight as I would like. Fueling is pretty good though.

Chad
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Old 08-03-2005, 01:08 AM   #17
bugman1964
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yeah im planning on tryin to pul lthe plugs tomorrow if thats the case i may take your map chad and drop the diel portion to about -40
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