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Old 09-04-2009, 11:19 PM   #141
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Nice job, it comes together pretty well. I'd probably have put it in a ziplock bag. :-) If you can put a small piece of alum across the back of the two transistors, it'll help to keep them from overheating. You'll know if your idle gets funky.
Oh yea, I have pieces of the aluminum I cut, Might as well hot glue a piece on there
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Old 09-04-2009, 11:23 PM   #142
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hahahaa
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Old 09-05-2009, 02:07 PM   #143
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CAS is pulled, Timing is set, Idle is working wonderfully at 950-1000. Still oscillates a bit, but it's nothing that big of a deal. I might try to see if I can achieve a lower idle than that later today.
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Old 09-05-2009, 02:12 PM   #144
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CAS is pulled, Timing is set, Idle is working wonderfully at 950-1000. Still oscillates a bit, but it's nothing that big of a deal. I might try to see if I can achieve a lower idle than that later today.
I was able to get the idle lower, but if you're open loop, you want a bit of a buffer so it doesn't stall when you turn on the fans, etc

Try to set the injector opening time by the two squirts/4 squirts method, then work on the fuel and timing map to get rid of that hunting. Then you can lower the idle if you want. And play with accel enrich settings. :-)
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Old 09-05-2009, 02:20 PM   #145
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THe injector opening time is usually 1ms isnt it? I had that setting on my MSI when it was still running up on it. The setting there thats newest to me is the PWM period in µsecs.
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Old 09-05-2009, 02:56 PM   #146
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If the injectors are high ohm, you don't need to worry about PWM. If you switch to low ohm, it's a nice feature to have.

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The idle issue:
It's very likely injector settings.

Let's say you turn on the injector at time 0. It doesnt' start to move for 300 us, and doesn't spray significant fuel until 1200 us. I'm picking numbers out of a hat to illustrate.

If you have open time set to 1500 us (1.5ms) then at idle when it tries to give you 500 us of fuel, it actually opens the valve for 500 + 1500 = 2000 us. The computer thinks you got 500 us, but really the valve opened in 1200, so you got the balance in fuel, or 800 us.

This is all great, and it'll idle and you'll never know it's wrong. Then you ask for 5% more fuel (slight throttle). The car goes "Great. 500 * 1.05 = 525 us. Open time of 1500 us, and that's 2025 us."

But what really happened? Before you were getting 700 us of fuel, now you're getting 2025-1200 = 825. Your "5%" increase was really only 3%.

Up top, with 9 ms of open time, you don't care about 200 us, you just tune it out. But right off idle it's very important to understand the opening time.



The fix: In the first settings window, there's a squirts-per-cycle, and I think your choices are 2 or 4. Since the open time is constant, switching from 2 squirts to 4 will double the error in opening time. So if you're idling at 14.6:1, and you go to 4 squirts and you richen up to 14.0:1, then you're opening time is too long. The math:


2000 ms (1500 + 500) becomes 2x (1500 + 250), so the difference between 1500 and 1200 shows up. Basically, go back and forth from 2 to 4 squirts and tweak opening times until there's no change, then go retune your low end.
I wrote that in like 2 minutes, the idea is right, I don't know the details.
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Old 09-05-2009, 09:41 PM   #147
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Thanks for the insight. I am running high imp RC's, so I wont be able to tinker out those settings too much.
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Old 09-05-2009, 09:49 PM   #148
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Opening times applies to all injectors. You need to do that or you'll never get a good idle.
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Old 09-05-2009, 10:06 PM   #149
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oh oh, you were referring to the PWM.. haha sorry.

Yea I will try to tinker with the opening times...

But as I read that, im TRYING to understand it. Ill keep reading more about the injector opening times, hopefully i can figure it out.

EDIT: So basically in a nutshell, I change the settings in the squirts per engine cycle to 4 instead of two. If it richens up, i need to lower the amount of the injector opening time correct? The perfect settings for the injector is that If i change the squirts from 2 to 4, and the AFR's stay the same, then the injector opening time is perfect?
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Old 09-05-2009, 10:14 PM   #150
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Bingo.
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Old 09-05-2009, 10:15 PM   #151
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Gonna try that now! Thanks!
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Old 09-05-2009, 11:11 PM   #152
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Made a world of difference. I had to keep playing around until i got my idle at a steady 850-900. My injector opening setting sits at 1.078ms. Im pretty content with that engine speed. Now, I have to figure out why the car has a rough time starting when its cold. During the cold start up, It catches, but then it dies quickly. I have to rev the motor to keep it up, where it finally settles. On a hot start, its starts up and keep its up on its own.

The car is too hot now to try to figure this out though. I gotta keep trying with settings the next time on a cold start.

When revving the motor, on decel (off pedal), the revvs drop down pretty hard to about 650-750 everynow and then, but its not very noticeable where it will become a nuisance. It does go back to the idle its at though previously, which is good. Its gets annoying sometimes trying to tinker out the settings on the car when youre not actually moving :-/

Anyway, When I change the duty cycle of idle valve, I dont notice any discernible changes. Am I doing something wrong?

Oh yea, the battery is now charging at 14.6. WEIRD.
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Old 09-05-2009, 11:16 PM   #153
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Made a world of difference. I had to keep playing around until i got my idle at a steady 850-900. My injector opening setting sits at 1.078ms. Im pretty content with that engine speed. Now, I have to figure out why the car has a rough time starting when its cold. During the cold start up, It catches, but then it dies quickly. I have to rev the motor to keep it up, where it finally settles. On a hot start, its starts up and keep its up on its own.

The car is too hot now to try to figure this out though. I gotta keep trying with settings the next time on a cold start.
There's after start enrichment, and idle valve taper speed. Both of these should make a difference - I have mine set pretty tight since I want it to return to idle quickly after a start, but I've had time to play with it to get it right. I'd start there.

Quote:
When revving the motor, on decel (off pedal), the revvs drop down pretty hard to about 650-750 everynow and then, but its not very noticeable where it will become a nuisance. It does go back to the idle its at though previously, which is good. Its gets annoying sometimes trying to tinker out the settings on the car when youre not actually moving :-/
I did this while driving, but adding timing/fuel to the cells below idle really help it recover well. Also, there's a setting for when it starts to fuel again on overrun fuel cut - make sure this is fairly high, 1500-2000, that was the motor is running on its way down

Quote:
Anyway, When I change the duty cycle of idle valve, I dont notice any discernible changes. Am I doing something wrong?
Are you changing it at the right temperature? It could be the valve isn't working, but my car won't even run that way!
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Old 09-05-2009, 11:16 PM   #154
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Jesus. I almost sound like I know what I'm talking about. :-)
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Old 09-05-2009, 11:24 PM   #155
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Lol, abe you are the MSII-Extra guru of MT.
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Old 09-05-2009, 11:27 PM   #156
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Yea, I am changing it at the right temperature, but i still see no discernible changes. I dunno whats up with my car

On the other hand, ill tinker with those taper settings, and below Idle, I do have my VE table pretty rich just incase it bogs. It should be good. Ill figure out the rest soon then tuning will start.

Oh, and ASE settings are pretty rich. When the car first starts, the AFRs sit at 12-13 until a few seconds have past. Its gotta be something with that taper setting.

I did take the car for a spin. I set the TPS to 100% and set the threshold high so AE wouldnt take effect so I can see where my base map sits. Right now, its running really rich on accel, so it looks like i have lots of tuning to do to get my regular driving cells back to what i had on MSI.
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Old 09-06-2009, 12:07 AM   #157
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Does the idle valve hum at all? Can you feel or here it when you turn on the car before starting? You should be able to. It worked here, so I don't think it's a design issue....
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Old 09-06-2009, 03:10 AM   #158
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hum? Like REALLY LOUD? or is it like a small hum? Does it sound like that when the car is always on, or only for a short second while the car starts up? I hear loud humming when the car first starts, but it cuts out after a few seconds. Im thinking its the fuel pump, but i have a stock fuel pump so it shouldnt be noisy like a walbro. But if the IAC is dead, then why would my car idle/start at all?

This has me thinking, What if its been dead this whole time? It probably is stuck at a position. Ive never cleaned it. Hell, i dont even know what it looks like :(

Reminds me, I need to get a walbro myself.

EDIT: Ok, educated myself a bit on what the hell the IAC looks like and where its located... I think im going to pull it out and clean it when i get the chance again.

EDIT2: When I still had the car in parallel and the OBDII was working, I received an error code of P0507, saying my idle sits high or some ****. I think my IAC valve is malfunctioning :(. Or maybe im just paranoid. I think i was throwing that code because my idle was sitting a bit higher than normal when i still had the MSI. The car idled better when it was higher, but it would fluctuate if it was lower. Maybe my IAC valve was bad from the start?

Im going to pull it off and try to clean it the next chance I get. Outta town right now.

Last edited by Marc D; 09-06-2009 at 02:16 PM.
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Old 09-06-2009, 06:13 PM   #159
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:-) The really loud one is the fuel pump - you just don't notice it unless you're listening for it, and it's like that when the car is running, you just can't hear it over the motor.

Odds are it was a vacuum leak or the throttle stop too high or similar making the car idle high, and throwing the valve. The idle valve hum is fairly quiet, but put your hand on it you can feel it, generally you can just hear it.
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Old 09-06-2009, 06:56 PM   #160
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:-) The really loud one is the fuel pump - you just don't notice it unless you're listening for it, and it's like that when the car is running, you just can't hear it over the motor.

Odds are it was a vacuum leak or the throttle stop too high or similar making the car idle high, and throwing the valve. The idle valve hum is fairly quiet, but put your hand on it you can feel it, generally you can just hear it.
I hear a "click" when the car stops. I think thats the VICS working though. I don't know if it is a vacuum leak or anything. I dont hear any kind of humming from the IAC valve at all. I checked the valve's resistance, and it checked out at 13-15ohms, which says its normal...

When the car starts up, it has a hard time starting on a cold start. To check is the IAC is working properly, I pulled the IAC connector while the car was running, and it shut down and stalled.... OK. When i tried starting the car again with the IAC not plugged in. It still bogs but it DOES IDLE.... the same way as if the IAC was plugged in. My Duty cycle at the specific temperatures im starting at is already over 40% Duty cycle, and ive tried to raise it up as much as 80% duty cycle with no effect, as it seems. The idle still sits VERY low during a cold start.

I havent tried to play with the taper settings, but im thinking that the valve could actually be stuck open or at a certain position?
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