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Old 09-05-2016, 06:59 PM   #1
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Default Lean and high idle after sequential conversion

I converted to sequential injection and I cannot get my idle low, and it is very lean. I did try open loop first and it was the same result so I switched to closed loop and same thing. I know I am to get open loop nailed down first, but I need some help. every time I try to richen up cells my idle just gets pushed higher, at one point I experimented and had -10 degrees timing in the cells above my idle cells just to keep the idle low....lol. I know sequential reduces fuel requirements but this is ridiculous. I've got tough skin so don't go easy on me, just give me solid advice if you would please, thanks -Dale
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Old 09-05-2016, 08:56 PM   #2
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Did you verify base timing with a timing light? Unlikely, but possible you're way advanced.

Do you have a massive vacuum leak? Your Idle Control Valve could be stuck wide open, it would make a very loud hissing noise, You could try unplugging it to see if it makes a difference or holding your hand over the opening.

Is your coolant temp sensor reading correctly? If it's reading very low it could idle you at 1500RPM

You definitely do not want negative timing, that can blow an engine.
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Old 09-05-2016, 10:27 PM   #3
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Did not verify base timing, I will tomorrow. I checked for vacuum leaks and couldn't find one. I do hear a hissing noise, but I believe that is coming from my intake. It's made that noise since I installed it...is assume that's normal. I'll try unplugging iac tomorrow. CLT sensor is reading correct values. One thing I forgot to mention, but I don't think it would cause this issue; the connector to my #1 injector broke i.e. it won't snap on and hold. I have it zip tied to my injector. If anything, I think it would cause a misfire, but my issue is high idle that happens to be lean. I do get a misfire when I decrease my VE idle table area, but that's to be expected. My car just wants to idle high and I have to lean it way out to the rpms down.
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Old 09-05-2016, 10:51 PM   #4
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Definitely need to set base timing with a timing light, you can get the cheap timing light from Harbor Freight and hook it to the #1 coil. Get a paint pen while you're at it and mark Top Dead Center mark on the crank pulley. Every time I've had a high idle it was a vacuum leak, either controlled or uncontrolled. The idle control valve is a controlled vacuum leak and if MS is not controlling it correctly it could be wide open. It's located in the middle of your intake manifold. If you recently went turbo or had lines off etc, make sure to check everything else, preferably with someone that can listen for leaks post throttle body. If you have a compressor and a blow gun you can compress the intake manifold with a piece of hose and test for leaks, listening with a stethoscope or using soap and water to check for bubbles.
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Old 09-05-2016, 10:58 PM   #5
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Lol, I've set base timing I just didn't realize verify it after sequential conversion. I thought the idle valve was under the throttle body?
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Old 09-05-2016, 11:00 PM   #6
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I hate auto correct
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Old 09-05-2016, 11:09 PM   #7
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Did you remove or block the air valve yet, one on the intake manifold? Do you know what the idle valve test mode is?
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Old 09-05-2016, 11:18 PM   #8
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I did not remove or block the air valve, I did do the idle valve test and it only works on 53%. Any higher or lower it runs like ****. When others say " I unplugged my idle valve" are they talking about the piece under the TBD or the air valve on the IM ? I've read a couple places to check a cap on the back of the IM , I don't know.
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Old 09-05-2016, 11:57 PM   #9
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Sounds like your idle bypass screw is set too high, your idle valve is broken, or the air valve on the intake manifold is sticking open. Either that or your tune is so terrible you can't get it injecting fuel linerally enough to keep an idle no matter what you do.

Crank the idle valve screw on the throttle body completely closed. Remove the coolant lines to the air valve and block it off somehow. Go read on how to tune idle, there's plenty of good stuff out there. You need to be using 153hz on the idle valve, not the 480hz the basemap comes with.


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Old 09-06-2016, 08:44 PM   #10
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I unhooked the electrical connection on the idle valve under the TB and started the car, I heard a loud pop and my idle was around 1000 rpm and 10.2 AFR. I reconnected the idle valve, put TS in open loop, and did the idle valve test. I was able to clearly and easily identify changes, I input those changes after I switched back to closed loop; 53% open, 35% closed and my idle was better than ever. I'm still very limited on getting ideal AFR's and a 1000-1200 idle, don't think its gonna happen with my car. Every time I add fuel in idle cells it lowers kpa but pushes my rpms too high without a comparable drop in AFR's. I'm idling 1100 rpm at 18 AFR....Good or bad? I ask because I read that others have issues with anything higher than stoich 14.7. Is this normal with sequential on our cars? To everyone who replied above thanks. You get a cat.
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Old 09-06-2016, 08:58 PM   #11
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No, 18.1 idle is not normal. My car would not do that, not physically possible to squirt that small an amount of fuel so it would act like a fuel cut.

You probably can't idle because you have your idle valve wide open, assuming you're using 153hz. 10 percentage range from 30-40% range should be all that's necessary.

You did close the throttle body idle screw, right? All the way clockwise?

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Old 09-06-2016, 09:10 PM   #12
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Yes I did close the idle screw all the way in. My car idles at 18.1 AFR, I can turn the AC on and everything. My Wideband is reading accurate as well, my garage smells like exhaust really bad and my eyes burn...lol. That's usually associated with running rich from my experience.
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Old 09-06-2016, 09:34 PM   #13
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Quote:
Originally Posted by WhiteMx-5 View Post
Yes I did close the idle screw all the way in. My car idles at 18.1 AFR, I can turn the AC on and everything. My Wideband is reading accurate as well, my garage smells like exhaust really bad and my eyes burn...lol. That's usually associated with running rich from my experience.
But 18.1 is really, really lean- not rich.
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Old 09-06-2016, 09:38 PM   #14
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Quote:
Originally Posted by stefanst View Post
But 18.1 is really, really lean- not rich.
lol yes, yes it is.
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