3s-GTE Base timing

[Ricco]

I'm trying to understand and set base timing on my 3s-gte MR2.  I'm a complete noob when it comes to ECU tuning and ignition timing so I'm trying to learn as I go.  I got some help with sensor configuration and calibration on the Facebook group but switched here so I could upload my log files and map file.  

Anyway, I tried to check base timing following this video here but I'm not convinced that I did it right. I understand that it's important to view the timing mark from the correct angle, which I believe is through the intercooler pipes on my MR2 - I first viewed the mark from the left of the intercooler pipes but it just made it look like it was at around 20 degrees advanced. The attached logfile "Set Base Timing" was my first attempt.. I think I made the mistake of closing the dialogue box and saving the setting to the ecu as it didnt seem to change anything and I think I was looking from the wrong angle anyway.

On my second attempt, I set the "Lock Ignition Timing to" 15 (which is how it was in the basemap file) and progressively changed the "Adjust Offset" parameter until the timing line on the crank pulley was at the 10degree marker, remembering to keep the "Set Base timing" dialogue box open.  When I viewed from between the intercooler pipes, I seemed to be able to get the timing mark to 10 degrees by using "-15" in the "Adjust Offset" field.

I understand that 10degrees base timing is called for, on these engines and I managed to get the timing mark lined up there but I still don't feel like it is right somehow. Any help to better my understanding here would be appreciated.

Engine first start - 2023-01-24 9;13;57 pm.llgx Set Base timing 1st attempt - 2023-01-24 8;37;47 pm.llgx Mr2-First start 1-24-23.pclx

[Adamw]

12 minutes ago, Ricco said:

On my second attempt, I set the "Lock Ignition Timing to" 15 (which is how it was in the basemap file) and progressively changed the "Adjust Offset" parameter until the timing line on the crank pulley was at the 10degree marker,

Since you have the "lock timing to" set to 15, you should be adjusting the offset until the timing light shows the 15deg timing marks are lined up.  If the engine doesnt have 15deg marks then change the "lock timing to" to 10deg and adjust offset until the 10deg mark lines up.  

Note you have to hit the enter key after typing in a new offset and you will see the text turn blue to confirm it is applied.  When all adjusted, then close the set base timing window and do a store.  

I just looked at you log and noticed that you are doing it without the engine running - this is not as accurate as doing it with the engine running, so dont spend too much time on it at this stage - instead just get it close enough to start, get it started, make a few adjustments if needed so that it idles on its own, then check base timing again with it idling.  

[Ricco]

Thanks. I just had another attempt and I think it might be correct now - I've just been trying to follow the setup procedure from the manual.  This time I set the base timing to 10 degrees and had to change the offset to -5 to get the crank pulley lined up with the 10 degree mark - Does that sound OK?  This time when I started the engine, it ran for longer before it died on its own, it almost stalled out at one point but then it recovered before stalling out shortly after.  

According to the manual, I should now adjust the master fuel value to get it to idle better now?  I've attached a couple more log files from what I've just done.

Engine 2nd start - 2023-01-24 10;35;27 pm.llgx Set Base timing 2nd attempt - 2023-01-24 10;32;27 pm.llgx

[Adamw]

29 minutes ago, Ricco said:

Does that sound OK?

Yep.

29 minutes ago, Ricco said:

I should now adjust the master fuel value to get it to idle better now?

Yep, most likely will need to increase the master.  You may have to drop the idle base position a bit if it idles too high when it has enough fuel.  

[Ricco]

Thanks for your help Adam.  On your advice, I adjusted the Master Fuel value from 9 to 10 and then to 11. The idle went from hunting like an old big block with a massive blower, to perfectly smooth like a Toyota .. I did not have to change anything in the ISC tables. (I've attached a log file for reference)

Back onto the thread topic, I checked the timing again with the engine running.   I was able to confirm that the light flashed at 10 degrees with my current settings (locked at 10 and adjusted offset -5) but I also found I was able to achieve the same result by locking the timing at 0 and using +5 offset.  My question is, which one is the right configuration and why?  

Also, I played with the adjust delay setting while revving the engine.. I found at 0 'delay adjust' that the timing light flashed at about 9 degrees (vs 10 it was at idle) but it stayed solid at 10 degrees with the adjust delay at 80ms (the value from the basemap) - Does that seem about right?

Once I was happy with the timing and the idle, I was able to successfully drive the car - I'm so happy with that result!  I do have some other questions now though, but I will start another thread.

 

Adjust Fuel Main to 10 then 11 - 2023-01-25 6;04;41 pm.llgx

[Adamw]

16 hours ago, Ricco said:

I was able to confirm that the light flashed at 10 degrees with my current settings (locked at 10 and adjusted offset -5) but I also found I was able to achieve the same result by locking the timing at 0 and using +5 offset.  My question is, which one is the right configuration and why?  

If its locked at 10 and shows 10 on the pulley, then if you change the "lock timing to" to 0 then the pulley should show zero with no change in offset.  So something is wrong there.  

Is it using a distributor or COP ignition?  Is the timing light a basic "non advance" light?

[Ricco]

1 hour ago, Adamw said:

If its locked at 10 and shows 10 on the pulley, then if you change the "lock timing to" to 0 then the pulley should show zero with no change in offset.  So something is wrong there.  

Is it using a distributor or COP ignition?  Is the timing light a basic "non advance" light?

When it’s locked at 10 with 0 offset, it reads 15 on the pulley.. It only shows 10 on the pulley if I adjust the offset to -5.
 

With it locked at 0 and 0 offset, it reads 5 on the pulley and I need to change the offset to +5 to get it to show 10 on the pulley. 

I’m using a distributor for ignition and my timing light is basic, no advance on the timing light.

Does that make sense?

I’ll double check this again tonight.

[Adamw]

35 minutes ago, Ricco said:

When it’s locked at 10 with 0 offset, it reads 15 on the pulley.. It only shows 10 on the pulley if I adjust the offset to -5.

When its locked at 10 it should show 10 on the pulley, so -5 is your correct offset.

 

35 minutes ago, Ricco said:

With it locked at 0 and 0 offset, it reads 5 on the pulley and I need to change the offset to +5 to get it to show 10 on the pulley. 

What you are trying to achieve with setting the base timing is that your timing light always shows the same timing as the ecu is commanding.  So if it is locked at 0, then you are commanding 0, it should show 0 on the pulley.  Im not sure why you are trying to get 10 on the pulley when you have commanded 0.  So the same -5 offset would give you 0 on the pulley which is what we want.  

[Ricco]

OK I finally understand.. Sorry for being a bit slow.  I did double check my timing as I said I would and here is what I found. 

When I command 10 degrees advance, I need an offset of -5 to get it to read 10 at the pulley.  When I command 0 advance, I need an offset of -8 to get it to read 0 at the pulley.  Not sure if that is a big deal or not but I left it at 10 and -5, thats where it seemed to idle the best.

 

 

[koracing]

This is definitely an issue of parallax vision when looking at the timing marks in an MR2 engine bay.  The 15 degree mark (furthest left) is the one you should be using as your commanded as it is the closest to straight up and down when you look at it, and any of the other timing marks will appear to have the crank pulley mark to the left of the timing cover mark when it's actually lined up because of the angle you can view it from.  The timing mark and cover design was originally intended for a front of vehicle engine installation and in the rear/mid engine location the passenger compartment is in the way.