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-   -   Ignition Timing 1999 Engine (https://www.miataturbo.net/megasquirt-18/ignition-timing-1999-engine-74700/)

mrpham 08-30-2013 02:25 AM

Ignition Timing 1999 Engine
 
Hey all.

I wasn't 100% sure where to post this but figure this is the most appropriate area.

Basic info:
1.6L 1999 engine (JDM import)
Using all the 99-00 cam and crank sensors, trigger wheel
280/270deg 10.5/9.5mm intake/exhaust camshafts
DIYPNP ECU and using the "Miata 99-00" ignition settings

Engine is running smoothly.

From what I understand, the use of stock trigger wheel means the base timing is set at 10BTDC and I shouldn't be using Tunerstudio's Trigger Wizard to offset anything. And this was the case when we first got the engine running, it was exactly on 10BTDC and we didn't need to offset anything.

But when I lock the timing at 10BTDC and check with a timing light, it indicates 15BTDC.

I have tried different timing lights, tried new cam and crank sensors, swapped in a different crank pulley and trigger wheel. And the problem persists.

I followed these instructions:
How-To: Setup Base Timing

And it does specifically say:
"Note: This How-To applies to most wheel decoders, but it does not apply to Toothed Wheel mode. This is because no offset should be necessary in Toothed Wheel mode. If your actual timing in Toothed Wheel is not the same as your commanded timing, there is a problem with your trigger wheel settings, most likely with your #1 tooth angle."

Does that apply to the 99-00 trigger wheel?

timk 08-30-2013 03:15 AM

Am I correct in saying you can't change the trigger settings, they are fixed when you choose "Miata 99-00"?

The crank sensor is mounted at 110 degrees and the trigger plate has teeth at 190 and 120 degrees per 180 period, so 80 and 10 degrees BTDC.

The fact that you were getting the right reading before makes me think it is a mechanical thing. Hopefully not a keyway issue?

Can you change the timing map where it is idling to 10 degrees to confirm it isn't a bug in the static timing mode?

mrpham 08-30-2013 06:20 AM

1 Attachment(s)
Hey Tim.

Which settings do you mean?

Will try change the timing map tomorrow and see how it goes.

Don't think it's a keyway problem, no wobble or anything. I also had all the timing covers off, aligned the crank gear to TDC using the mark on the oil pump, confirmed that it was TDC using my oil dipstick down cylinder no.1. I than put the crank pulley and lower timing cover on, and the crank pulley timing mark matched with the T mark on the plastic cover. Just like this:

https://www.miataturbo.net/attachmen...ine=1377858030

Zaphod 09-02-2013 03:17 AM

2 Attachment(s)
Ignition settings on the NB (99-00) engines are nearly the same on all the cars.

The trigger offset is from about 4 to 6° (I have 5° - see here.)
And there is no difference from the 1.6 to the 1.9 - as you can see I also have the 1.6 (Euro spec) 99 car.

This also is the same on MS2 and 3

https://www.miataturbo.net/attachmen...ine=1378106240

Godless Commie 09-02-2013 11:26 AM

Any chance we could see your timing table?


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