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MK2 Turbo3 Ignition Timing - 12 degree?
Topic Started: Sep 26 2017, 02:13 PM (478 Views)
CMA


Did I set at wrong timing of 5 degree?! :shock:

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I always thought 5 degree on both NA and T3.


I am planning to advance ignition timing much as it can without ping.... Is 12' degree for T3 too much? Even at 20' degree ?!
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92MHB
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new to metro's but not new to cars so someone may correct me --just trying to help

don't know about the mk2 turbo, but did you use a jumper lead to short the 2 terminals on the plug on the drivers firewall by the strut tower before checking timing?

with my '92 metro 1.0l not jumped, it read 12-13 degrees --once the jumper was inserted it read 3 degrees and I needed to advance it , the spec on mine is 5 degrees from factory, but most guys advance to 8 degrees
Edited by 92MHB, Sep 26 2017, 08:05 PM.
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CMA


I did think about to check ignition timing without jumper lead it. ;p

Actually I know that T3 has knock sensor but I am curious what is max degree without loss power at mid- high range? :shock: (I am not able to find that more information about knock sensor)
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suzukitom
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Tom

My 91 MK2 Chev Sprint T3 hood emissions sticker says to set 5 degrees BTDC with jumper in place.
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CMA


Yeah It surprised me that 5' on the hood as you took picture of your T3.

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I think I would trust 12 from the manual.
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freegeo
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Most manuals state to check the emission sticker.
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CMA


What do you mean? is it for emission reason... or You said that 5' is better than 12' for emission?

I read quickly read this link , https://link.springer.com/article/10.1007/s12544-013-0099-8 but I believe every engine is different.
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freegeo
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I have just about every year metro manual and most of them say refer to the emission sticker for what to set the timing too. That's what the factory recommends. You can set yours to whatever you want, it's your car.
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CMA


Yeah I can do whatever I want to do with my car but I am trying to understand the purpose of factory set at 5' vs FSM at 12'


Of course I want aim for the optimal torque/hp ratio to mpg :lol
Edited by CMA, Sep 27 2017, 12:19 AM.
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suzukitom
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Tom

CMA, I noticed that the FSM (T3 EFI Turbo System) supplement page you referenced does not specify whether the timing check is performed with the DLC jumper pins shorted. This could explain why the FSM timing value is stated as approximately 12 degrees BTDC instead of the 5 degrees BTDC value in the hood emissions sticker with the DLC jumper shorted.

I would expect that setting the static timing at 5 degrees BTDC with the DLC jumper will give you a more repeatable result, as the ECM base timing is frozen.

If the idle speed is out of normal range, timing adjustment may be inaccurate. I recall that your current warm idle speed appears to be above 1000 rpm, so that should be corrected first. (if you have an accurate tachometer to measure this) :D
Edited by suzukitom, Sep 27 2017, 12:49 AM.
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CMA


You are right... it doesn't say anything about jumper lead.

Yeah I will do both IT and IAC. (I am pretty sure cleant FI made it rev higher) but I don't think IAC set will effect on IT very much.


IT = ignition timing
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suzukitom
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Tom

Well, higher rpm usually results in more advance. It is easier to see this data pattern on an OBD2 car during cold start / warm up.
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freegeo
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That picture you posted from a manual is for idle speed not for setting timing. There should be a procedure just for timing, or look in the timing chain / belt changing procedure to see what it says about setting timing.
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92MHB
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thats why in post #2 I asked if you were using the jumper lead??? your manual did not say to use the jumper---I also noted that with out the jumper in my vehicle it measured 12-13degrees, but with the jumper it was 3

I read somewhere that if you don't use the jumper then once the timing gets to a set point, it doesn't change without the jumper lead installed ---to properly adjust the timing the jumper needs to beinstalled

but for your real question, I have no idea how far advanced you can set it before you have problem with knocking/pinging --- that would probably be dependent upon the condition of your motor and ignition system, your atmospheric conditions, fuel grade etc
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CMA


What is for then? The idle speed is should be based on IAC adjustment. (not show on the next page)


Nope there is no procedure for timing in T3 FSM except in NA ignition timing FSM.
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