Erratic Tach

[envmyz]

Hey guys,

After pounding my car this morning I got in to go to lunch, gave it hell a few more times, and all of a sudden my tach jumps all over once it goes around 3,000. Jumps around about 3-5000 and misses like crazy. Sounds to me like possibly my pullup resistor came disconected, shorted, loose or I'm getting interference from something else.

 

So does this sound like a tach wire, pullup resistor problem? It runs great at idle and up to about 2500-3000 rpm.

 

Help me out before I leave from work....it's a long way home....lol

 

Thanks

 

Chris

[auxilary]

resistor in the tach is fried. Common on 73-74 tachs. You may wnat to look into replacing the tach with an autometer or equivalent unit

[envmyz]

Once again, answered my own question. I love MS, troubleshooting is such a breeze.

After taking it home I knew that there was probally only 3 causes of this erratic tach.

 

1.) Connection inside the box that I made to use LED17 spark output was loose.

2.) 1K pullup resistor was shot or came loose

3.) Power wire to the dizzy weak (or ground)

 

Well it ended up being 3, power wire had been bent over so long that there was only 1 strand of wire connected..

Rewired, routed the power source wire, and wham ran perfect again.

 

Just upgraded last night to the Alpha Code 25i6....had some issues (my dumbass) with timing..but I got it.

I like the first start feature of this new program, it hopefully will help with cold starts for the first time of the day. Trigger the flood clear mode three times and it goes into the first start mode...very cool. Well tonight is going to be the FIDLE hookup, if it works, it was a 17 dollar investment