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  #51  
Old Mon 23rd January 2017, 10:33 PM
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Donkeytits1 Donkeytits1 is offline
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Oh and I took a nice photo of it because I washed it and I could.



I'm not becoming one of those wanky car guys am I?

Surely I can't be with that horrible front bar...
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  #52  
Old Tue 24th January 2017, 12:34 AM
pitrack_1 pitrack_1 is offline
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some thoughts....

1) I thought snapping the throttle shut usually results in a momentarily rich mixture (or at least did with carbys) as the air is removed but he fuel remains or keeps coming through for a short period...although the reduced flow can lead to higher temps. Two ways to reduce this: EGR and/or extra fuel and of course EGR is what they've done since the 70's.

2) For it to 'rev hang' (oooh, fleeting petrol version of diesel runaway )along with extra air it also needs extra fuel...has it stopped sending the fuel to match the reduced air through the air bleed caused by your restrictor plate? My thought is the extra fuel will get to the cat and perhaps lead to elevated temps there, possibly damaging it (along with NOx of course)

Enough thoughts from me, they're likely to cause trouble....

Cheers and GREAT WORK!!!,
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  #53  
Old Tue 31st January 2017, 11:35 PM
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Patrick_1: Cheers for the response man, its good to be challenged think a bit deeper about these things!

1) TBH, I have for along time thought rev-hang, and the vacuum dashpots on carbs, where for NOx reduction. I first read about it when I actually owned (still do) a car with a carb - 1st gen Honda Prelude, and was wondering what the non functional dashpot hanging off the throttle was for. I haven't challenged the NOx belief in along time, and I cannot remember the original source. Its true I just didn't question my assumption and went ahead and wrote the previous post, so I could be wrong.
I see your logic - fuel is flowing, with an abrupt reduction in air supply the mixture turns rich until the fuel supply rate restabalises. Rich means high levels of unburnt hydrocarbons, which is another environmental concern they were trying to combat with emissions controls early on.
So I've had a bit more of a read, so far have found no real authoritative source that say one way or the other. Certainly this site says its an NOx reduction measure.
Either way, rev hang is there to improve some aspect of emissions performance, and unfortunately it makes driving a manual a shitter experience :P

2) The orifice plate will not have an effect on fuel mixture. The engine has two ways of knowing how much air is going into it, the Throttle Position Sensor and the Manifold Absolute Pressure sensor. (The computer also knows the opening position of the idle solenoid valve, and this is the same kind of information as the TPS input). Calculating air volume from TPS is woefully inaccurate at low throttle openings, so the system relies almost entirely on the MAP sensor (*1). The MAP sensor is downstream of the idle air control parts, so it is responding directly to whatever air the idle control valve lets through. So orifice plate or no orifice plate, the mixture is not effected.

(*1) Mainly because a tiny change in throttle position at low throttle openings creates a large change in air flow, and there needs to be a calibrated table for TPS opening vs air flow stored somewhere which would vary a small amount from car to car. At low throttle openings, this small variance would cause very bad air flow readings. The reverse is true for MAP readings.

Last edited by Donkeytits1; Tue 31st January 2017 at 11:47 PM.
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  #54  
Old Tue 31st January 2017, 11:54 PM
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So been playing about a bit
- The orifice plate seems to be the main thing reducing rev hang, unfortunately it does greatly effect stall protection. I would rather have smoother gear changes than have stall protection, so I don't care. Carbs never had stall protection, and we lived without.

- The air assist creates a weird thing where while the cars moving with the clutch in or in neutral the ECU keeps the revs above 1,500 RPM and pulses it up and down between 1,500 and 2,100 RPM. So you sound dumb when coming up to lights, but when you stop it settles into a nice idle. It also reduces engine braking. I'm assuming its some Auto thing. I do not understand what the control circuits between the TCU and ECU really do - I just know how to stop CELs. And that they are labled "torque control". If I can find somone with a running H6 Outback they are willing to let me observe I might be able to probe it and see if I can treat those inputs better. All this before I release the wiring diagrams :P

Last edited by Donkeytits1; Tue 31st January 2017 at 11:58 PM.
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Old Wed 1st February 2017, 09:30 AM
pitrack_1 pitrack_1 is offline
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HI Donkeytits,

great work again.

Perhaps some monitoring- have you got FreeSSM or ROMRaider or an OBDII reader hooked up? That way you could monitor exactly what it's doing (or trying to do). Not sure if OBDII will work with 2001 as it's pre Aussie-OBD mandate. You could possibly remap with ROMRaider too. Lots on other forums. I must say I've simply stuck to OBDII for our diesel as it proved problematic due to moving to CANBus (VAG-COM/KKL cables wouldn't work) and have left it at that for a few years now.

Thanks for your link re: rev hang, I actually have a '04 SP23 (i.e. L3 engine), hadn't noticed the rev hang (it is slightly older than quoted '07 which is likely series II) or it hasn't affected me driving. But I think I have noticed it when revving the engine in neutral. I will go looking for it now of course!

I have/have had a few other cars I may have noted rev-hang on too.
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  #56  
Old Thu 2nd February 2017, 09:31 PM
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Patrick_1: I've got a ELM327 dongle, and it works great with the android app. Once I get my lappy working I'll try FreeSSB. Highly doubt I can really get into the ECU though, enough to see whats going on with the TCU interface. In the android app, I can see all the sensors listed and some things are not listed there, like idle air solenoid position and anything TCU related.

I'll do a little more research because it would be pretty cool to work with FreeSSB.

I have read some threads on the RomRaider forums specifically regarding ditching the automatic logic from the EZ30D ECU, and all those threads are now dead. They did delve into the code, and found allot of strange tables and other things that I think they gave up trying to work out. So kinda suspect there is only so far you can go with flashing this ECU.

But I think I have my motor running well now, so I may not need to.
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Old Thu 2nd February 2017, 09:32 PM
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Solved the high idle while moving. And, well, durr. It was an air leak.

So playing around with the idle air control valve and the orifice plate caused me to remove the rubber seal, which was swollen and wouldn't fit back in. I thought any leakage would be negligible, turns out I was wrong.

It appears that the valve returns to a pre-set position when the ECU knows the cars moving. With the air leak, that leaves enough coming through to hold the revs too high and cause poor driving at slow speed. The valve only appears to operate in closed loop when the car is stationary. The surface of the manifold where the IACV mounts has an oring channel, and is not machined, it is raw from the casting. So its conceivable that some air could leak.

I think I miss diagnosed the air assist being the problem because it of course it has some airflow associated with it aswell. So remove it from the equation and the revs drop. Two and two! My preference it is of course to run with air assist, so I'm glad it's not causing the problem!

With the orifice plate, an oring on the manifold side on the idle air control valve and some silastic the revs now sit at 1,000 to 1,150 RPM while the car's moving, and slow speed driving is much improved. Gear changing is nice and predictable, and I'm getting smooth. It's nearly as good as the EJ22 was.

So I think I've got it driving nice now, with an IACV clean and an orifice plate. Air assist hooked up and unmodified.

Last edited by Donkeytits1; Tue 7th February 2017 at 10:37 AM.
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Old Thu 2nd February 2017, 11:03 PM
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And of course it's the simple things...Another great result! Love how it's moving forward (literally) .
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  #59  
Old Fri 17th February 2017, 08:23 PM
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Quote:
Originally Posted by Donkeytits1 View Post
- The air assist creates a weird thing where while the cars moving with the clutch in or in neutral the ECU keeps the revs above 1,500 RPM and pulses it up and down between 1,500 and 2,100 RPM. So you sound dumb when coming up to lights, but when you stop it settles into a nice idle. It also reduces engine braking. I'm assuming its some Auto thing. I do not understand what the control circuits between the TCU and ECU really do - I just know how to stop CELs. And that they are labled "torque control". If I can find somone with a running H6 Outback they are willing to let me observe I might be able to probe it and see if I can treat those inputs better. All this before I release the wiring diagrams :P
This is definitely an auto thing. my EJ22 auto converted to manual does the same. I have been meaning to install a manual ecu to sort it out. one day..

I dont have the air leak though. mine revs at about 1200 until i come to a stop.

awesome build mate. i used to play around with stuff similar to what you are doing so I can appreciate the effort you have put in
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And just to clarify the real 4WD thing, Subarus are an unreal 4WD.

Last edited by vincentvega; Fri 17th February 2017 at 08:27 PM.
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  #60  
Old Sat 18th February 2017, 07:15 PM
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Cheers man!

Engine's sorted now. Runs nicely. Wish the EZ had a manual ECU I could drop in, that would have made life allot easier.

I've found in other 'proper' manual Subarus I've driven since that idle air don't operate on closed loop while moving either - Their idle is always a little high when moving, and settles on stopping. 1,200 doesn't sound too bad, the EZ sits between 1,050 and 1,150 now which is totally drivable. Don't even notice it

EJ22's have a pin you can ground I'm pretty sure, to tell it whether it has a manual or an auto tranny on it. Grounded being 'Auto'

Last edited by Donkeytits1; Sat 18th February 2017 at 07:49 PM.
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