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Discussion Starter · #1 ·
just looking for a little help from anybody who could help me figure out the idle issues my car is having. seems that the AEM cant control the idle of the car since the unit isn't made for the IS300. so one tuner added a lot of fuel to compensate. but then I'm running super rich all the time. i took it to another shop and they leaned it out but now the car stalls all the time. like when I'm sitting at a stop sign or red light the car will just lean out and stall. very frustrating but sounds like there's no happy medium. anybody having similar issues? any input?
 

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I think this is in general with all standalones, you need to find that happy medium where the car will idle fairly smooth while keeping it as lean as possible. As much as I hate to say it this can mean high 11s and low 12s. Don't get fixated at trying to idle at 14.7:1. Without having the ability to control drive by wire you're at the mercy of the stock ECU.
 

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Actually, you can try to put in a Idle Air Control valve. The main problem is that the engine isn't getting enough air at the target AFR 14.7 you're trying to reach. Add in the IAC and you should be able to idle up. At least that's what I'm planning to do to fix my rich idle.
 

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I've heard adding a few degrees of timing at idle areas can help a little too.
 

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I thought there was a pretty good thread about this a little while ago.

If a piggy can run a stoich good idle with larger injectors, a standalone should be able to also.

I think the key point is software. The standalone's tune-ability must have flexibility of when the injector is on-off as to be effectively burning the air/fuel mix at idle (in relation to where the engine and cams are in teh 720degree cycle). I do not have hands on with the AEM standalone, but when using the AEM FIC for larger injectors, it needs the "injector response time" information to be accurate in the fueling. This is the time it takes 12vdc to actually open the injector, consider it the delay time. You may need to move the AEM's pulsewidth on time around to get this right at idle.

Second is timing, set the timing to the OE idle setting of 10 degrees advance, don't assume the EMS's cal file is perfect, confirm this with a timing light. Any faster of an idle will just close the throttle body via DBW (imagine what o2s are to closed loop, RPM and thus timing is to DBW "closed loop"), thus the need to run stupid rich to burn whatever little air is getting in when DBW has compensated for your high idle.

Transition from cold start to operating temp idle RPM could be an issue too. If the standalone's transition is later than when the OE ECU wants it, consider the DBW to be in "closed loop" and will learn around the standalones timing using throttle control.

I haven't gotten to practice this yet with my standalone, but its one of the challenges I've known would have to be taken on when I start dialing it in.
 

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BlackSportD, I have a feeling that the engine is just not getting enough air. That's maybe why it needs to run so pig rich 12.5:1 to have a smooth stable idle at 700rpm. I'm going to try to add in an IAC soon to see if that helps out any. Then again, I've seen a few guys here that have the car idling perfectly dead on at 14.7 and it didn't look like they had any IAC rigged up.

BTW...for anyone with the 2JZ-GTE VVTi swap with DBW throttle body. My cold start is at like 2500rpm lol. I think it's because the throttle body is 3" diameter vs the 2JZ-GE 2.75". The throttle plate is openeing the same angle on both butterflies since I still have the stock GE ecu. But the GTE TB being 3" will idle higher than the stock GE one even though the opening angle is the same.
 

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^^^ I've said this too many times and no one listens.

Absolutely yes that the motor is not getting enough air.

There's a set screw on the TB that sets the minimum aperture it can close down to. Open it a bit.

While I'm not on standalone... My GTE idles perfectly. 14.7 and cold starts at 1700rpm and hot idles at 720rpm.
 

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^^ I'd give trying to tune around DBW a shot first ;) Having a larger throttle body adds a variable, and I think that cold start will be that way regardless of tune but when at temp maybe if you could get a timing light on it, set the idle to 10 degrees and then play with the a/f and whatever else the AEM has to mess with the injectors. The larger throttle body shouldn't be an issue with the standalone or Emanage Ultimate guys.

I think this is the .net modern equivalent to when peeps were asking about tuning piggybacks around OBDII lol.

Malek has a good idle with his Tec, and also says he could get the AEMs to idle at stoich, but him saying that is about as much useful info I think you'll get. I'd love for him to prove me wrong and provide some good details.

I wish I could be hot on this myself, but I've still to send my Innovate POS with its RMA # in.
 

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Discussion Starter · #15 ·
BlackSportD, I have a feeling that the engine is just not getting enough air. That's maybe why it needs to run so pig rich 12.5:1 to have a smooth stable idle at 700rpm. I'm going to try to add in an IAC soon to see if that helps out any. Then again, I've seen a few guys here that have the car idling perfectly dead on at 14.7 and it didn't look like they had any IAC rigged up.

BTW...for anyone with the 2JZ-GTE VVTi swap with DBW throttle body. My cold start is at like 2500rpm lol. I think it's because the throttle body is 3" diameter vs the 2JZ-GE 2.75". The throttle plate is openeing the same angle on both butterflies since I still have the stock GE ecu. But the GTE TB being 3" will idle higher than the stock GE one even though the opening angle is the same.
cold starts is not my issue. cold starts are fine. its when the car has been driven for a little bit. for example say i start the car up, let it warm up, then drive over to another spot and shut it off. like if i have to make more than one stop. say i stop at the gas station, post office, bank whatever and turn it off then when i go to restart it, it'll give me a hardtime to restart . the car wont stay on without me reving the motor. and when its on it wants to stall at the next trraffic light.
 

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^^ So it runs fine when warmed up, but if you turn the car off, then on again its stubborn to start and will die out in idle?

Does the AEM have a "priming" setting (injectors will open in a certain way and only for startups) for cold starts? Or for any kind of start?
 

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cold starts is not my issue. cold starts are fine. its when the car has been driven for a little bit. for example say i start the car up, let it warm up, then drive over to another spot and shut it off. like if i have to make more than one stop. say i stop at the gas station, post office, bank whatever and turn it off then when i go to restart it, it'll give me a hardtime to restart . the car wont stay on without me reving the motor. and when its on it wants to stall at the next trraffic light.
im having the saaaaame exact problem. does yours ever go super pig rich at idle when you drive it around for a bit and then come to a stop?
 

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Make sure you have a properly setup intake temp IAT sensor hooked in the right place. That was really screwing me over for a while(actually it wasn't even hooked up lol). I had a problem with hot starting(gas station/grocery store quick stops, and hard time idling/starting after). Try to place the IAT after the intercooler and as close to the TB as possible. I know for you GE guys, it's a bit tougher since the damn turbo sits right under the intake pipe. Putting a turbo blanket on the turbo will help cure that problem biiig time. You also have to make sure your temp compensation maps in the EMS are tuned correctly.

The reason it's doing this is because once you come to a stop, the air starts to heat up big time. At cruising/higher rpm the air is flowing faster so the temp as sensor is relatively close to what goes into the motor. In traffic or stops, the air is moving slow and has a longer time to capture heat from the charge pipe above the turbo and heated top mount intake mani on the GE. The temp reading and what actually goes into the motor is WAAY different. And we all know hot air at the same fuel mixture will run rich as hell.
 

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Discussion Starter · #20 ·
Make sure you have a properly setup intake temp IAT sensor hooked in the right place. That was really screwing me over for a while(actually it wasn't even hooked up lol). I had a problem with hot starting(gas station/grocery store quick stops, and hard time idling/starting after). Try to place the IAT after the intercooler and as close to the TB as possible. I know for you GE guys, it's a bit tougher since the damn turbo sits right under the intake pipe. Putting a turbo blanket on the turbo will help cure that problem biiig time. You also have to make sure your temp compensation maps in the EMS are tuned correctly.

The reason it's doing this is because once you come to a stop, the air starts to heat up big time. At cruising/higher rpm the air is flowing faster so the temp as sensor is relatively close to what goes into the motor. In traffic or stops, the air is moving slow and has a longer time to capture heat from the charge pipe above the turbo and heated top mount intake mani on the GE. The temp reading and what actually goes into the motor is WAAY different. And we all know hot air at the same fuel mixture will run rich as hell.

mmh i'll have to look into this. i dont know where the IAT sensor is. TurboEast did the install. i do have a tuboblanket and my downpipe is wrapped but under the hood does get pretty hot
 
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