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-   -   Setting base timing (https://www.miataturbo.net/megasquirt-18/setting-base-timing-99679/)

rrjwilson 03-27-2019 11:57 AM

Setting base timing
 
Ok so my MS3 Basic is in. I've calibrated my wideband, sorted my MAP sensor and wiggled my TPS so can now set my base timing.
I follow the instructions to set fixed timing from Rev.
So i connect my timing light to the alternator cap as positive and the throttle cable mount as ground slide the induction sensor loop clamp thing over cylinder 1's HT lead.
Set my advance to 0° so it shows the correct reading.
I crank the car and it leaps into life.

Here is my concern though.
  1. AFR shown is 7.5 which is bad
  2. Timing mark is not even visible under strobe (video included)
Here are my current guesses as to what is wrong:
  1. CAS has slipped at some point due to improper bolt tightening (how can I fix this accurately?)
  2. The car is not at fixed timing as it is warming up. Wait 10 minutes of running and try again.
  3. Timing belt is totally fucked and its only through Thor's mighty graces that my car has never exploded (although its only done <10,000 miles)
  4. I am a complete spanner and should be using the timing light with the advance set to what i am looking for (ie 10°)
I realise I have not addressed the AFR but i figure that is at least partially warmup enrichment.

rrjwilson 03-28-2019 03:52 AM

So I have cleaned the timing area up a bit, found the notch and marked it.
Results have not changed however.
The interesting part is using the timing advance wheel on the timing light i can bring the notch into view (video linked).
The concerning part is the timing advance is way past the measured limit of 60° and is approximately 75° advanced.

Possible Epiphany the CAS is reporting on something it sees NOT is interacting with and because the crankshaft and camshafts are linked via the timing belt the CAS is imply talking shit.
Please can someone who tinkers more than me tell me I'm not mental in this idea.

This means a manual CAS realignment and subsequent tightening will solve the timing "error" because it is not an error its a lack of accuracy because the sensor is reading in the wrong place.

sixshooter 03-28-2019 05:39 AM

The outer ring with the marks is a separate piece from the center. The two are bonded with a rubber ring between them. Your rubber has failed and you need to consider a replacement. This is common and something you should have noticed being mentioned by others.

rrjwilson 03-28-2019 06:02 AM

Thank you. Part ordered (before 1pm delivery).
I simply didn't realise this timing swing was a symptom of that.
Is there ANY chance that it is not the rubber? ie the CAS has just slipped or something else minor I only ask because it doesn't seem to wobble.

So it looks like its a simple procedure:
  1. Remove belts
  2. Undo four bolts
  3. Swear with penetrating fluid and hammer
  4. Remove pulley
  5. Install new pulley
  6. Do up four bolts to torque (which i haven't looked up yet)
  7. Install belts
The incredibly annoying thing is my insurance requires pictures of its current state and by thursday next week and the crank pulley is £150 new.
A working VVT motor with warranty delivered is £280. So I could have just done that but I have no where near that sort of time because of the insurance.
This however has spurred my anger to move up because I could have just swapped it out.

sixshooter 03-28-2019 07:05 AM

It isn't uncommon for people's timing marks to be 90° out and the motor operating as if nothing is wrong. It just makes it nearly impossible to time the ignition again after they have moved.

MetalMuffins 03-28-2019 08:44 AM

You could also (I assume) make a piston stop, measure TDC and re-mark the pulley to get your base timing set without replacing the pulley. Just keep in mind that it could still move, so if you ever need to recheck or reset timing, it may be off again.

rrjwilson 03-28-2019 11:19 AM

New pulley arrives tomorrow.
Plenty of swearing will commence.

I would love to attempt to find TDC although cranking the engine by "hand" seems like i should be really hard. It surely isn't just yank on the crank bolt.
I can probably create a piston stop or use a long screwdriver.

MetalMuffins 03-28-2019 11:52 AM


Originally Posted by rrjwilson (Post 1528628)
New pulley arrives tomorrow.
Plenty of swearing will commence.

I would love to attempt to find TDC although cranking the engine by "hand" seems like i should be really hard. It surely isn't just yank on the crank bolt.
I can probably create a piston stop or use a long screwdriver.

Give this a watch:

sixshooter 03-28-2019 01:08 PM

If ring is moving then damper is trouble and needs to be replaced anyway.

Alejo_NIN 03-28-2019 02:54 PM

can base timing be set wihtout the lower timing marks?
like, setting the thing to TDC and going form there or is the cover absolutely necessary?

rrjwilson 03-28-2019 05:34 PM

Ok so I've removed the old pulley ready for the new one arriving tomorrow.
Only mild swearing so far.

sixshooter 03-28-2019 05:54 PM


Originally Posted by MetalMuffins (Post 1528578)
You could also (I assume) make a piston stop, measure TDC and re-mark the pulley to get your base timing set without replacing the pulley. Just keep in mind that it could still move, so if you ever need to recheck or reset timing, it may be off again.

I think it'd be really difficult to tell where you are in that last 5 degrees plus or minus. 5 or 10 degrees is a lot when you're talkin about forced induction.

rrjwilson 03-30-2019 06:20 AM

I'm going to post this as I have found it odd.
I have a long nose pulley 8 slots but I couldn't get the pulley off without taking out the crank bolt as the bolt simply covered the opening that should have let it just slide off.
All long noses are meant to be the same 4 bolts for the pulley and it just slides off. Short noses are the sods where the crank bolt must come off.
So I am concerned that i have a short nose with a long nose pulley or a long nose with a short nose bolt.
Of course there is the possibility (haven't looked) that it is a short nose retaining washer thing and long nose everything else.
Here are my pictures for your perusal

rrjwilson 03-30-2019 08:51 AM

Good news. It is a long nose and the pulley could have slipped over the bolt.
However the belt retaining jumbo washer was stuck in the pulley and needed persuasion.
I will put up photos of the slippage later.

rrjwilson 04-02-2019 08:24 AM

She's ALIVE.
Gotta get her ass of the jack stands now.

Went full bore and bought TunerStudio MS Ultra and MegaLogViewer HD so can do anything that is necessary.
Of course I basically watching YouTube all the time to learn.
There is just so much more information displayed in TunerStudio in comparison to the Emerald software. The difference 12 years makes is immense.


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