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By fireflyse
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#14380
I have two G10T swaps that will not compensate for engine loads such as in gear(automatic), electrical loads or A/C loads. The Team Swift archive seems to be useless. I was told there was a man in London Ontario that went by the handle Bumhead Dave on Team Swift that had experience with this. My MKI is factory and the idle controls work perfectly.
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Last edited by fireflyse on Thu Aug 25, 2022 1:49 am, edited 1 time in total.
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By fireflyse
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#14440
You have to start somewhere I guess. My attempts to locate someone with direct experience has yielded zero so lets see what we can find. The engine is a MKII LS3 G10T, bored to 75 mm with Vitara pistons, 3Tech head with larger valves, ported and polished, gasket matched with an OEM cam. The fuel system, ecm and turbo are all stock. It’s been trans-planted into a 1992 Metro convertible with an automatic and A/C. I have no control over engine load detection or correction.
When I put it in drive, the idle drops. If I add electrical loads, headlights, fans etcetera the idle drops to the point of stalling the engine. If I turn on the A/C in gear it will stall as soon as the compressor engages. The A/C works fine if the car remains under throttle.
Today I got the service manual out and adjusted the TPS according to procedure using a .6mm feeler blade. At least I know the ecm knows where the throttle is now.
Next will be a base timing adjustment, then a base idle adjustment and a full diagnostic tour of the ISC VSV and the A/C idle up VSV just to make sure those parts and systems are working. Last will be an inspection for vacuum leaks.
After all that I need to check if the A/C amplifier is connected to the ecm and that the ecm actually sees an A/C on signal. While I’m there I will patch the TCM in gear signal into the A/C on signal and see where all this gets us. I hope I don’t need a diode.
Am I missing anything?
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By jamalspelling
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#14442
I presume you have the timing dialed in to compensate for the lower compression pistons,
so I would skip that, base timing specs do not apply here.
Your timing should be adjusted for driveability/performance, the motor was modified to
power the vehicle, not the A/C. Of course it would be nice to power the A/C and still
have it stable at low RPM. But you may be on the right track… Where is your timing set now
with this build? I had one wouldn’t run worth a crap at stock settings, I think
I had to run it around 30 ° advanced with the Vitara pistons.

Then skip everything else and go straight to the IAC solenoids first and check for
proper operation, are they still working? Do they have power..Wires intact, do you hear it buzzing?
What happens when you move the thumbscrew knob,
does it affect the idle? You are correct as well, the entire vacuum system
should be inspected thouroughly for any breaches, everything from the oil cap
and dip stick to PCV and all vacuum lines, throttle body bolts & gaskets etc.
Some clear pics of the engine bay on the suspect vehicle would probably
rally more replies and suggestions.
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By fireflyse
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#14443
jamalspelling wrote: Thu Aug 25, 2022 10:01 am

I presume you have the timing dialed in to compensate for the lower compression pistons,
so I would skip that, base timing specs do not apply here.
Your timing should be adjusted for driveability/performance, the motor was modified to
power the vehicle, not the A/C. Of course it would be nice to power the A/C and still
have it stable at low RPM. But you may be on the right track… Where is your timing set now
with this build? I had one wouldn’t run worth a crap at stock settings, I think
I had to run it around 30 ° advanced with the Vitara pistons.

Then skip everything else and go straight to the IAC solenoids first and check for
proper operation, are they still working? Do they have power..Wires intact, do you hear it buzzing?
What happens when you move the thumbscrew knob,
does it affect the idle? You are correct as well, the entire vacuum system
should be inspected thoroughly for any breaches, everything from the oil cap
and dip stick to PCV and all vacuum lines, throttle body bolts & gaskets etc.
Some clear pics of the engine bay on the suspect vehicle would probably
rally more replies and suggestions.

This is a MKII and based on previous discussions you’re not familiar with it. That being said I appreciate your input. The block and pistons were intended for my MKI build but I found an NOS MKI short block so the convertible got this one.

I want to set this up as close to stock as there never was. A few turbo automatic convertibles made it to Canada back in 88 for the press to see but it never made production. I am more far more interested with driveability and function than power performance. The engine runs well otherwise. The cam is not advanced. It starts easily and has good drivability. It doesn’t ping on regular 87 gas. It has a complete Bosal replacement exhaust with a cat, resonator and muffler as well as the stock downpipe.
The timing has never been set with a timing light following manufacturers procedure. That will be done today if my friend can help with a timing light.
Nothing happens on the thumb screw as it is only on the A/C VSV and only works with the A/C on.
The Idle Speed Control VSV has no thumb screw and is not adjustable. It functions via a PWM signal.
Today I will verify the integrity and function of the vsv’s as they do not have codes in the ecm for those circuits. I also want to insure the signals between the TCM, ECM and A/C amplifier are all intact. The MKII turbo ECM has provisions for A/C but none were ever built factory with it.
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By fireflyse
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#14444
@jamalspelling would you like a copy of the MKII Turbo Supplement?
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By fireflyse
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#14445
I confirmed circuit function for the ISC VSV , the evap VSV and the A/C VSV. All three function as normal. I started the engine and it went to 1500rpm. I warmed it up and idle setttled in at 800. I went around with a blue bottle of gas and could not register any change. As soon as the compressor was engaged it stalled. Just for chits and giggles I ran the A/C VSV adjuster screw all the way in (closed) The engine stayed running. I put it in gear and it stalled. Still no idle control but at least I’m a little ahead of where I was. I’m inspecting every hose for a leak, and found nothing. I went to a friends shop and used his timing light. I had to retard it seriously to get it down to 8 degrees in diagnostic mode, i might be off a tooth
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By fireflyse
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#14446
Yes one tooth advanced, I’ll need to reset the base timing but I still have no control. The screw on the A/C VSV is in all the way(closed) I can over adjust the base idle and it will stay running in gear now but it revs to 1300 in park. The thing is when it’s when it’s idling and the A/C is running and I try to adjust the A/C VSV screw off of closed it will stall the engine as soon as it leaks. The engine will only stay running if the valve is entirely closed. that’s opposite to the way it should work
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By jamalspelling
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#14448

@jamalspelling would you like a copy of the MKII Turbo Supplement?

Heck yeah! That would be awesome.

Yes one tooth advanced

Fix that first, that might be the sole issue.

as well as the stock downpipe.

Does this have a precat like the MK1? If so, the worn element may have
shifted, causing a restriction in the exhaust, which could affect vacuum
and contribute to your issue.

So..Did you do the swap, or did you have someone else do it,
or acquire it that way?

MKII and based on previous discussions you’re not familiar with it

Doesn’t matter, IAC concept is the same on all vehicles. Add air, bypassing the
throttle plate to create stable idle under load. Drive by wire vehicles eliminate
external IAC by controlling throttle plate..we’ve come along way.

These are my thoughts..
You may have some suspect issues noted in the pics to follow..
You said the belt is off 1 tooth, fix that first, then set the timing and idle.
You have the lower compression Vitara pistons, factory timing specs
are out the window, set it where it feels and sounds best at an
appropriate idle. If you use the factory specs, I suspect it will fall
on it’s face and you will see unburnt hydrocarbons in your rear view mirror.

If you’re still having issues, then bench test the IAC motor(s) and verify flow.
They are prone to carbon fouling, perhaps they may need to be cleaned out
with carb cleaner or simple green.
You can also try disconnecting the hoses and then plug the end of
the hose with your finger, restricting the flow completely, then allowing
a slight flow, and see if there is a change in RPM. I have no idea if they
are plumbed correctly with this swap.

And, check the air filter.

Cheers,
JS

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By fireflyse
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#14449
jamalspelling wrote: Fri Aug 26, 2022 11:24 pm

@jamalspelling would you like a copy of the MKII Turbo Supplement?

Heck yeah! That would be awesome.

Yes one tooth advanced

Fix that first, that might be the sole issue.

as well as the stock downpipe.

Does this have a precat like the MK1? If so, the worn element may have
shifted, causing a restriction in the exhaust, which could affect vacuum
and contribute to your issue.

So..Did you do the swap, or did you have someone else do it,
or acquire it that way?

MKII and based on previous discussions you’re not familiar with it

Doesn’t matter, IAC concept is the same on all vehicles. Add air, bypassing the
throttle plate to create stable idle under load. Drive by wire vehicles eliminate
external IAC by controlling throttle plate..we’ve come along way.

These are my thoughts..
You may have some suspect issues noted in the pics to follow..
You said the belt is off 1 tooth, fix that first, then set the timing and idle.
You have the lower compression Vitara pistons, factory timing specs
are out the window, set it where it feels and sounds best at an
appropriate idle. If you use the factory specs, I suspect it will fall
on it’s face and you will see unburnt hydrocarbons in your rear view mirror.

If you’re still having issues, then bench test the IAC motor(s) and verify flow.
They are prone to carbon fouling, perhaps they may need to be cleaned out
with carb cleaner or simple green.
You can also try disconnecting the hoses and then plug the end of
the hose with your finger, restricting the flow completely, then allowing
a slight flow, and see if there is a change in RPM. I have no idea if they
are plumbed correctly with this swap.

And, check the air filter.

Cheers,
JS

Image
Image
Image
Image

I tried to attach the supplement here but the file is too large. We keep the supplements available in the files section here: https://www.facebook.com/groups/swiftlife or I can email it to you.
vacmap.jpg
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vac map.jpg
vac map.jpg (135.58 KiB) Viewed 531 times
The off tooth was repaired before my last post. Base timing was set to factory specs. There are no driveability issues. Timing was never the issue I just put it back together a tooth off last week during an oil leak repair.
I did the build, installation and connector re-pinning. This is not my first swap but has been a persistent issue with these swaps. I am concerned with it now because it’s my wife’s car. i can deal with it on my own, I don’t want her to have to deal with it on hers.
The pre-cat is in the stock down pipe and is intact and functional.
In spite of your opinion on scotch locks, they have no effect on vacuum. They are temporary.
The clamps from the factory are intact. The sketchy hose you see was repurposed from an N/A map sensor as the original was missing. It is sealed and the fuel pressure regulator functions normally. The open pipe by the throttle is the fresh air intake for the A/C VSV. The factory didn’t put clamps on the VSV hoses. This is the set up that came with the car from factory and it worked admirably on the N/A engine. The plug you circled is the factory position for the fresh air intake hose. I tried to find 10×0.9mm barbs but no one carries them. I did hook them up to the correct spots on my other MKII swap but to no effect. None of the things you circled or pointed out are leaking. I can screw the throttle idle all the way in and it will just barely idle indicating there are no other uncontrolled leaks - its running on the air meter bypass air(factory sealed). The air filter is a factory lifetime unit that was cleaned and oiled before re-installation. All other intake air pipes have factory clamps in good working order and are sealed.
The A/C VSV circuit and function have been verified. The VSV is working when the A/C is turned on, but the only way to keep the engine idling is to close the vent screw fully. Opening it even slightly will cause the engine to stall. Idle is stable and normal with the A/C off and no air passes through the VSV. The A/C on signal from the A/C amplifier is getting to the ECM.

To this point I have only tried to get it to compensate idle with the A/C on. Today I will test the function of the idle speed control VSV.. It only functions when light loads are detected such as brake peddle application, heater fan motor/defogger (no defogger in a vert) or headlights are turned on. It is PWM so I just have to touch it with a stethoscope to verify electrical function.

I have not even begun to tackle the in gear signal from the TCM. There is no ECM receptor for that signal. The ECM doesn’t know the vehicle is in gear. My thought is to patch that signal into the ECM A/C on signal circuit. It may not be a perfect solution, but it might work too. I’m thinking once I gain control of the A/C VSV I’ll just increase the operating rpm to be able to run the A/C with it in gear at idle comfortably. We don’t drive it in winter.
I would kill to find an ECM from one of those press turbo verts.
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By fireflyse
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#14450
Mmm sidetrack central. The fed ex truck arrived with a $900 seat for Breezy so I spent the day detailing it - then it started raining, tomorrow perhaps.
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