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Check timing EDIS/Distributorless


Rustpile

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OK, I´ve tried to find a way to check my timing, but I can´t find any good way. The problem is that my 36-1 wheel is a bit off(a lot, really, 20 degrees approx.). That is a problem for another day however. What I need to know, is what my timing is, at a given point.

 

I don´t know what my actual advance is, so I need to check it, somehow. I can adjust my timing at will, but I need a reference. So, is there a reference?

 

Currently getting the head rebuilt, and I don´t want to break a rebuilt head(it was not that cheap...)

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If the head is off then you have the perfect opportunity to make sure you have a good timing mark.  Make sure the #1 (and #4) pistons are at TDC then check your flywheel for the OT mark looking through the timing hole in the bell housing right behind the starter.  IF you have an aftermarket flywheel there might not be a mark, if not you need to put one on the flywheel RIGHT NOW so you have a good known mark when the engine is back together.  If you are running a toothed wheel on the front for your ign trigger you most likely do hot have a mark on the pulley any longer.  If you want you can mark the front pulley now just for another back up timing mark. 

 

Remember if you are using wasted spark coils and an adjustable timing light you will NOT get a good reading!  The timing light will be getting a signal every crankshaft  revolution not every other revolution.  the reading on the timing light will need to be 2X the timing your are trying to set.  If you want 15 deg BTDC at the crankshaft  you will need to set your timing light at 30 deg.  If you want to make a mark on the flywheel or front pulley at 25 deg (the factory "timing ball" on the flywheel) you will have to calculate the number of teeth on your timing wheel and count teeth from your TDC mark.  I suggest you start out with a maximum advance of 32-34 deg BTDC at 3500 rpm and above 12-14 deg at idle and a curve that puts you at 25 deg BTDC at around 1800-2000 rpm as a good starting point. 

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At TDC the 36-1 wheel needs to be 90 degrees (9 cogs away from the missing tooth at the VR sensor center) and of cousre you know that. Set engine to TDC and as stated above place a mark on the pulley or trigger wheel that is dead on TDC. You can then measure the actual degrees of offset. Thinking you should be able to subtract or add that number to your programing. I.E. if you are truely off 20 degrees approx, that should be factored into the base bin #'s in your mapping. The ignition control program will provide timing info.

 

Best to set your trigger wheel to TDC with a reference mark ultimately. Show us a picture of your trigger wheel, might have an answer on that. Mine is below but on a turbo pulley.

 

 

post-33884-0-07591900-1418335442.jpg

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EDIT:If you have managed to get the motor to run you can use the Embedded Ball (BB) on the flywheel to check your timing, it is 25 degrees BTDC, so if you set your timing in studio tuner fixed at 25 degrees you should see the Ball in the gearbox window (using a non adjustable timing light)

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...and if you want to make a mark at anywhere other than TDC, measure the circumference, divide by 360, and there's your 'single degree' increment.

 

So if you wanted a 90 degree mark, it'd be the circumference times 360/90.  It's pretty easy...

 

I like to mark the front pulley, so I can see what the mark's doing.  But it IS technically less accurate.

 

t

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This might be a stupid question, but anyways:

 

I marked TDC on the pulley, just a white marker on the engine and on the pulley that aligns. Found the OT mark, marked that too with some white. Counted the teeth from sensor to missing tooth. Counting the one covering the sensor, it was 7.

 

Now, can I simply turn the pulley to get 9 teeth, as the head is off, and with the gear in neutral? The cam gear(the sprocket) is still on, so I would just have to "skip" a couple of teeth, and bolt the cam gear to the cam, with both valves on cylinder #1 closed, and it would be good to go? Of course, I would have to turn the engine by hand, to check that it is actually correct.

 

That means, the mark on the cam pointing directly at the oil distributor when engine and cam is at TDC, right?

 

And when into this: If I would just keep it at 70 degrees, am I correct in assuming that I just have to add more advance, so 10 degrees of advance, would be 30 degrees in the program?

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You are at 7 teeth (70 degrees) now which explains your assumption of approximately 20 degrees off.

 

9 teeth (90 degrees) away from missing tooth is what you want, however it really should be set at TDC with the rest of the engine markeings. Otherwise it only makes more guesswork later on. Setting the mapping is much guesswork to begin with. Who wants to factor in all the additional advance and retard figures. Although if noted you will remember later. Good points atop on flywheel marks as a basis for your offset, albeit 25 degrees. More math to figure. YES the programing would need to account for the missing 20 degrees.

 

A general rule of thumb is that the cam sprocket hashmark will align with the oil distributor when at TDC but you have to be certain it is not 180 degrees off by looking at the flywheel too.

 

Good luck:

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Can I simply turn the pulley to get 9 teeth, as the head is off, and with the gear in neutral? The cam gear(the sprocket) is still on, so I would just have to "skip" a couple of teeth, and bolt the cam gear to the cam, with both valves on cylinder #1 closed, and it would be good to go?

That means, the mark on the cam pointing directly at the oil distributor when engine and cam is at TDC, right?

 

And when into this: If I would just keep it at 70 degrees, am I correct in assuming that I just have to add more advance, so 10 degrees of advance, would be 30 degrees in the program?

 

 

As of now, cylinder 1 and 4 is on top, 2 and 3 bottom. OT mark is visible, so it should be on TDC. Can I just turn the crank pulley to get the last two teeth I need/want, and put the cam in?

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As of now, cylinder 1 and 4 is on top, 2 and 3 bottom. OT mark is visible, so it should be on TDC. Can I just turn the crank pulley to get the last two teeth I need/want, and put the cam in?

 

No, you need to keep the crank/cam settings as factory spec, changing that relationship could be messy or terminal.

 

With the engine at TDC as per factory you need to either move the VR sensor so it is 9 teeth before the missing tooth

 

or

 

leave the VR sensor where it is and take the 36:1 wheel off the crank pully and reposition it on the pully so the missing tooth is 9 teeth from the vr sensor

 

This guide might help, its for Megajolt but the toothed wheel positioning is the same http://www.autosportlabs.net/MJLJ_V3_vehicle_installation_guide

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