Duraspark II distro cranking too slow for MSII V3.0?

[mattscot007]

Trying to get my first MSII install going, and I cant seem to get an RPM signal to the MS.

The stimulator works, and when I pull the distributor from the motor and spin it with my hand QUICKLY, MS registers the RPM signal and goes to cranking mode. The truck doesn't turn over this quickly though.

I am using the VR circuit on the V3.0 board. Is this just too slow for VR? Do I need to go to a TFI distributor and switch to the hall effect circuit? I dont want to spend the money if this distributor will work fine.

I am not sure on the polarity of the wires for the VR sensor. One is purple/blue stripe and the other is orange. I have tried reversing the polarity of these two wires, and either way works when spinning the distro by hand.

Please Help, I am stumped.

[Bernard Fife]

mattscot007,

Genrally, very slow isn't a pronblem, if the VR inpout circuit is working (I have spun a HEI distributor over at ~50 rpm and the coircuit triggerred fine).

However, the VR input circuit may not be working as intended. It is entirely possible to have it working on the stim, but not properly, if one or more of the transistors have solder bridges. The effect is that the circuit triggers down to about 2.5 Volts, but not below (I have seen this on the bench). The may be near the output of the VR sensor at idle speeds (it is for HEI systems) , so it shows up as erratic triggering at idle or no signal while cranking.

So make sure the VR circuit is built well, and that there are no solder bridges on the very small transistors. If there are (or if you aren't sure), use a solder wick (a small braid of fine copper strands) and a hot soldering iron to reflow the solder and soak up the excess. Check the other VR circuit components as well to make sure they are well soldered and not bridged.

Lance.

[mattscot007]

I will check that out right now. Could the pots for the VR circuit create the problem that I am having if they are wrong? I am going down to pull the MS from the truck now and was wondering if there was another thing to check while I had it out.

Thanks again

[mattscot007]

I checked the board for soldering problems and did not find anything. I am at a loss.

[mattscot007]

I think that it was the pots not being set correctly. I am getting a tach signal now. All I have to do now is get it started