newbie hei8 eratic spark when 5v applied

[rich454mc]

Hi. I have been searching through the forums on this , and I see a bunch of people have had this same issue but it seems when the problem gets fixed , no one continues to post that it was indead fixed. Anyways. using an Ms2 v3.00 on a 454 chev with an 8 pin HEI small distributer. My problem is that the engine will start and run fine without the 5v "B" wire hooked up. when I hook the wire up, the engine will yank and back fire. I have tried another distributer with the same results. I have done the mod from DIY autotune which involves changine the circuit to feed off the 5v signal with a 100 ohm resistor and changing the pickup to falling edge. this did not change anything. I have heard of a transistor mod but I was wondering if anyone has had this problem and knows of a solid solution before doing this mod. thanks in advance.

[rich454mc]

sorry. firmware 2.92

[rich454mc]

well I could'nt get the HEI to work properly so I scrapped the whole thing and went with a full msd setup. I built the vr circuit as in step 65 and did all the appropriate mods. I now have a new problem. I get proper tach signal to the ms2, but I have no spark output. I checked it with a test light and have no switching ground signal to the msd6al on pin 36. Am I missing something. In the msd area of the manual in shows I should install d1, d2, c12 and c30. but thats in a chart under the v2.2 board but shows the v3. I am confused.

[Matt Cramer]

How is the spark output side of things set up?

[rich454mc]

I figured it out. after going over everthing 5 times , I realized that I had a bip373 instead of a vb921. i did'nt use the mica insulator and the driver was shorted. installed the mica and now I have spark.