DIYEFI.org Forum

60 at the cam is 120 at the crank. I am not sure if my angle is totally stock because the cam usually has a tab that fits opposite a tab in the wheel that only allows it to be inserted in one position but on our cam the tab was broken off and the wheel could actually be inserted in however many position there are teeth(maybe 12 or so). Anyways I had to kinda eyeball it and put it in where it looked like it was stock but I could easily be off a tooth or so either way as its hard to see where its going when you insert it. The stock adjustment also has a lot of room for play and I just parked it near the middle. I just stuck a led in each coil plug and inverted my spark so one was lit most of the time and then hand cranked the motor to see what was on where, then I hard wired it accordingly. I wasnt totally sure if I had the cylinders oredered right until I cranked it with the timing light and I just happened to get it right on my first try. I believe I ended up with cylinder one triggering off of the leading edge of smallest inner hole(4 count) which was actually the longest count before it starts over when counting inbetween like I did and nissan supposively does. I got it started with a trigger angle of 88 btdc for now. This would put the next hole(the longest one) about 30 deg after TDC. Nothing ended right at TDC for me but this is a more ideal trigger angle anyways. I have not fine tuned the trigger angle yet or investigated it as much as I plan to, I just got it sparking close to start to see if it would run and it did. I am trying to not to start it any more untill we can actually get it out and start breaking in the rings.

Nice job beav.

Just like the good old days! Lining up the 'spark output' with the cam has been a problem forever. Lining up the Nissan tooth wheel 1-of-12 ways sounds just like lining up the gear drive on a good old points distributor!

<hijack> btw: The rings are broken in after being dragged 10miles/16km across the cylinder wall. Multiply the crankshaft stroke by 2 passes per revolution, and divide into 16km to get the total number of revolutions. The motor is 'broken in' after a few minutes run time. </hijack>

Guys I have finally completed the code to listen for knock between
10btdc and 50atdc with ability to determine which cylinder is knocking.

Real world testing is now in progress.

I have real world tested RPM which is used for the variable sensitivity over RPM.RPM comes from the spark pulse.

Next will be ignition timing .

Then Knock Windowing..

Assistnace need

When I use on of the signals from the distributor i.e cam or crank
I have no issues. However when I try to connect both to
the interrupt ports the engine seems to want to die. Any idea on how to read the signal without affecting the engine?

I would need to see a general circuit to better help, but here's a shot at it. I'm guessing the signal is being loaded by this new electrical draw. You can decrease your load by adding a opamp in a voltage follower configuration. The TL082 is known as good for this type of application for a variety of reasons. The datasheet also includes a example voltage follower setup with output filter to prevent oscillation.

http://datasheet.octopart.com/TL082IN-S ... -20031.pdf

See page 8 fig 1.

The nissan outputs are 5 volt outputs and I am connecting directly to the
PIC. I would have thought PORTs configured as inputs would not load the source.

Are the PIC pins set to inputs? If so they should be fairly high impedance say 1 mohm ish. The datasheet would tell you the exact resistance. If they are set as driving they can typically draw up to 20 mA so around 250 ohms. At 250 ohms, you can still pull it high and often can get a registered value when read. You might want to check if they are inputs or driving.

You could check if you are loading your OEM circuit down by putting a resistor in series with the pin, and using a scope on dif mode, take look at the voltage across the resistor. If the pin is high impedance, it shouldn't have a noticeable current through that resistor, and therefor shouldn't produce a measurable voltage. If it is loading the circuit, a noticeable current will flow through the resistor, then you'll see a voltage.

You might want to connect some resistors inline to limit current anyway. I'm unsure of hardwar specs on those things, but i know ms1 vs ms2/ms3/freeems is 20mA vs 2.5mA per pin, max. In the latter case 1.6k is the safe value to use.

Fred.

Pins are set to input.Will try the resistor this weekend.

this sounds like a level issue. opto's are usually open-collector - therefore you need a pullup somewhere.

what is 'connect both' ?