That doesn't matter. No tachometer will work until you find that gray wire that's supposed to be there for the ready to run MSD distributors.
The 8552 distributor that I have is about 10 years old, maybe more. I just got off the phone with MSD tech support who told me that the addition of the gray wire was done about four years ago and that I need to use the coil (-) terminal since I don't have that wire. This tach that I have was perfectly capable of displaying a steady engine speed until this Fitech setup was installed. I can't imagine how performing the install would suddenly damage the tach.
Maybe there's some sort of interference going on then. Try routing the tach wire a different way, or shield it somehow. You could also run an MSD box with that distributor and use the dedicated tach output on the box.
I used to have a problem with the factory tach on my Olds, driven from the TACH connection on the HEI. After some testing the problem was determined to be noise coming into the 12V source lead. I added a modest radio style filter cap (maybe 10 ufd at 100V) to the power input, inside the tach, and the problem was gone. Not sure this applies to this situation. Bruce Roe
I have some wire shielding on order. I took a look at the speedometer cable and the adapter box and didn't see anything outwardly wrong with it. I unscrewed the cable from the adapter box, pulled it out, plugged it back in, and screwed back on the screw cap thing on the end of the cable. Excuse my inexperience here but are speedometer cables supposed to be stiff? It was not the easiest thing to get realigned to the adapter box. Took the car for a spin after that. The speedometer behaved normally for about a minute and then dropped back down to zero. Really hope I don't have to replace the speedometer gear inside the trans.
Further investigation reveals that the square hole in the end of the speedometer driven gear is rounded out. The fitting that holds that gear in and that has male thread for the speedometer cable is seized into the case of the trans. We're letting some PB Blaster do it's thing on it right now so we can unstick it later.
Started a tach related thread in the fuel injection section: http://www.v8buick.com/index.php?th...mpatibility-with-fitech-and-6al-boxes.357461/
I was able to bring the car to a different shop where they were able to at least fix the tach problem on it. Their invoice states three things: 1. The coil wasn't getting a full 12 volts, so they "created" a circuit to feed the coil from the ignition switch. 2. The tach was hooked to the wrong side of the coil. Currently it is hooked to the negative side which I thought was the case before, and is the way that FiTech indicates in their diagram it should be hooked up. Not sure what they really changed here 3. They installed the RF shielding I bought. I had also asked the new shop to lower the engines idle speed since it was a bit high. They did so; and in combination with the above three things the tach issue has been alleviated and the thing runs awesome. The idle speed is near stock, and I believe the fuel injection allows it to run at a lower idle than the moderate street cam would otherwise allow. I like it!
The square hole in the speedometer driven gear is rounded out and the gear is supposedly broken. The bullet fitting holding the gear into the case is seized into the case. That problem will wait until after the fourth of July when I can get my transmission builder to look at it.
