Damaged tooth causing issues??

[frdboy]

[frdboy]

[jsmcortina]

It is worth looking at the tooth logger and comparing it to the examples in the manual. The composite logger has value, but here the tooth logger is going to be clearer.

James

[frdboy]

[jsmcortina]

That's horrible.

Try to zoom in some more with your scope. I think you are getting multiple false triggers at each zero-crossing.

Check the trim pots aren't in backwards too.

James

[frdboy]

That's horrible.

Try to zoom in some more with your scope. I think you are getting multiple false triggers at each zero-crossing.

Will do later this evening, I did try adjusting R56 up and it seemed to clean up the square wave but it started to lose where the damaged teeth are.

Check the trim pots aren't in backwards too. as in physically backwards?

James

[billr]

Both "backwards" possibilities: Make sure they aren't swapped one for the other, they look the same; and be sure the adjusting screw is on the end towards the heat-sink bar.

[frdboy]

Both "backwards" possibilities: Make sure they aren't swapped one for the other, they look the same; and be sure the adjusting screw is on the end towards the heat-sink bar.

They are both installed with the screw towards the heat sink, how do I make sure the right one is in the right spot?

[frdboy]

That's horrible.

Try to zoom in some more with your scope. I think you are getting multiple false triggers at each zero-crossing.

Check the trim pots aren't in backwards too.

James

Like this?

[jsmcortina]

Exactly like that.
Something is wrong in your VR conditioning circuit, either components or setup.

Double check that the zero-crossing trip voltage is as close to zero as you can get it.
http://www.msextra.com/doc/pdf/html/MS3 ... .4-71.html

James

[frdboy]

Exactly like that.
Something is wrong in your VR conditioning circuit, either components or setup.

Double check that the zero-crossing trip voltage is as close to zero as you can get it.
http://www.msextra.com/doc/pdf/html/MS3 ... .4-71.html

James

Lowest it goes is .6 V

[billr]

One pot is 100K ohms and goes closer to the heat-sink bar. The other is 10K. There should be a P/N on those, it may be hard to decode, but "10" will be someplace in the number on one pot and "100" on the other. If in doubt, post what you see. Note: If I am wrong about which pot goes closer to the heat-sink, somebody please correct me! I am doing this from memory...

[DaveEFI]

Other thing is, having checked for replacement pots in the UK recently, is that most are 22 turns these days. I couldn't find a 12 turn with inline pins from any UK supplier.
Which would make a big difference if you work to number of turns for adjustment.

[jsmcortina]

Lowest it goes is .6 V

That sounds about right.

Check that the U7 chip is an MC34072AP also.

James

[frdboy]

U7 Looks to be MCP6002E

[frdboy]

I did replace the damaged toothed wheel also.

I have an event I need this running for in a just over a week, do you think if I bought a hall effect crank sensor it might run? I can figure the VR part out later but I am running out of time. My only other option I guess would be to reinstall the distributer and see if I can get it running that way.

[ashford]

according to this pic you should be triggering off the falling edge.
another thing i have found is some of the sensors you get at the parts stores are junk, getting an oe one is best. if the ferrite core is broken from a fall / contact with the tooth, i have seen them give stupid readings.

[frdboy]

according to this pic you should be triggering off the falling edge.
another thing i have found is some of the sensors you get at the parts stores are junk, getting an oe one is best. if the ferrite core is broken from a fall / contact with the tooth, i have seen them give stupid readings.

I may have had the wires switched in that pic, I did switch polarity back and forth for testing.

I have tried both an OE and aftermarket sensor, this sensor/wheel was running last month with MS2 and EDIS.

Thanks

Adam

[DaveEFI]

I did replace the damaged toothed wheel also.

I have an event I need this running for in a just over a week, do you think if I bought a hall effect crank sensor it might run? I can figure the VR part out later but I am running out of time. My only other option I guess would be to reinstall the distributer and see if I can get it running that way.

There are many thousands of MS running perfectly with a VR sensor. The very first thing I'd do is check your VR input circuit on MS is working correctly. Examine all the components carefully - are they the correct ones? Has solder flowed to both sides of the board? Is there continuity on all of the appropriate PCB tracks? Can you adjust the voltage at Pin3 of U7 with R56 according to the data given?

If you have a Stim and a dual beam scope, you can look at the signal into and out from the VR circuit at the same time, and make sure both pots have an effect.

If you have an audio signal generator, a sine wave from that is pretty close to the signal you get from a VR sensor, and you can then see that being amplified and converted to an approximate square wave. With a 36 tooth wheel, RPM is about half the audio frequency in Hz.

[frdboy]

I did replace the damaged toothed wheel also.

I have an event I need this running for in a just over a week, do you think if I bought a hall effect crank sensor it might run? I can figure the VR part out later but I am running out of time. My only other option I guess would be to reinstall the distributer and see if I can get it running that way.

There are many thousands of MS running perfectly with a VR sensor. The very first thing I'd do is check your VR input circuit on MS is working correctly. Examine all the components carefully - are they the correct ones? Has solder flowed to both sides of the board? Is there continuity on all of the appropriate PCB tracks? Can you adjust the voltage at Pin3 of U7 with R56 according to the data given?

If you have a Stim and a dual beam scope, you can look at the signal into and out from the VR circuit at the same time, and make sure both pots have an effect.

If you have an audio signal generator, a sine wave from that is pretty close to the signal you get from a VR sensor, and you can then see that being amplified and converted to an approximate square wave. With a 36 tooth wheel, RPM is about half the audio frequency in Hz.

I bought this from DIYAutotune pre-assembled, I have no experience with working on or assembling ckt. boards or parts.

I understand there are many out there and working......this one is not and I am running out of time.