MSD 6al

frank rymas · 03-29-2002, 04:34 PM

Installed a MSD 6al and an MSD dist. in my 83. When I hooked up the stock tac. to the tac. output from the MSD my tac. reads nothing...... When I hook it to the coil (MSD blaster) the tac. seems ok off idle but at idle it jumps from 650 rpm to 2000rpm. The motor speed does not change with this jump. Any ideas?????

sn95gt19 · 03-29-2002, 05:45 PM

i would check the ground for the tach

RoadWarrior · 03-29-2002, 06:40 PM

You might need to get a tach adapter.

DRASTiK · 03-30-2002, 02:57 AM

If I remember correctly (it's been a while), the MSD directions specifically state NOT TO CONNECT A TACH TO THE COIL. That's why they have the tach port on the ignition box itself. I had similar problems when I used my tach on the coil. I could rev my motor to the moon and back and the tach would only read about 2700 RPM, whether I was at 3000 or 6000, it would just stop and stay at 2700. You need to use the tach output port on the box. An adapter for this is the right way to go.
Dave

Mach 1 · 03-30-2002, 03:23 AM

I have my aftermarket tach hooked up to the msd box and my factory tach to the coil. Both work perfectly. I used to have my aftermarket and factory connected to the coil before the MSD box and both worked. I dont think your problem is not being able to use the coil wire for the tach with the MSD box

Thad · 03-30-2002, 09:53 AM

Do you have an eec computer or are you running a carb with no com. If you have an eec com you don't have to hook the tach up to anything. msd has a direct plug-in harness that allows you to bypass the stock ignition and go to the 6AL without cutting any wires. this also allows the eec to control the tach through the msd without having to directly connect it. the tach isn't entirely accurate but should rev throughout all rpms.
If you have no eec com, running a carb, then you have to connect it to the 6AL unit not the coil. There is a direct tach plug-in on the oppposite side of the power wires. You should have gotten a harnees with the unit. if i'm correct, you also have to run a ballast at the coil.
If you still have problems give MSD a call, (915)857-5200.

03-29-2002, 04:34 PM	#1
frank rymas Registered Member Join Date: Mar 2002 Location: macomb mi Posts: 4	MSD 6al Installed a MSD 6al and an MSD dist. in my 83. When I hooked up the stock tac. to the tac. output from the MSD my tac. reads nothing...... When I hook it to the coil (MSD blaster) the tac. seems ok off idle but at idle it jumps from 650 rpm to 2000rpm. The motor speed does not change with this jump. Any ideas?????

03-30-2002, 02:57 AM	#4
DRASTiK Registered Member Join Date: May 2001 Location: Yuma, AZ Posts: 536	If I remember correctly (it's been a while), the MSD directions specifically state NOT TO CONNECT A TACH TO THE COIL. That's why they have the tach port on the ignition box itself. I had similar problems when I used my tach on the coil. I could rev my motor to the moon and back and the tach would only read about 2700 RPM, whether I was at 3000 or 6000, it would just stop and stay at 2700. You need to use the tach output port on the box. An adapter for this is the right way to go. Dave __________________ Dave 88 GT - 13.4@106 on street tires (2.2 60ft) My Stang RHC member #75 My stang is FOR SALE!!

03-30-2002, 03:23 AM	#5
Mach 1 Registered Member Join Date: May 1999 Location: Georgia Posts: 3,866	I have my aftermarket tach hooked up to the msd box and my factory tach to the coil. Both work perfectly. I used to have my aftermarket and factory connected to the coil before the MSD box and both worked. I dont think your problem is not being able to use the coil wire for the tach with the MSD box __________________ 2002 GT 1993 GT (SOLD) '93 Mustang GT RHC member #142

03-30-2002, 09:53 AM	#6
Thad Registered Member Join Date: Oct 1999 Location: Stuart, FL US Posts: 192	Do you have an eec computer or are you running a carb with no com. If you have an eec com you don't have to hook the tach up to anything. msd has a direct plug-in harness that allows you to bypass the stock ignition and go to the 6AL without cutting any wires. this also allows the eec to control the tach through the msd without having to directly connect it. the tach isn't entirely accurate but should rev throughout all rpms. If you have no eec com, running a carb, then you have to connect it to the 6AL unit not the coil. There is a direct tach plug-in on the oppposite side of the power wires. You should have gotten a harnees with the unit. if i'm correct, you also have to run a ballast at the coil. If you still have problems give MSD a call, (915)857-5200. __________________ 90 LX 5.0 ,bored 302, MSD 6AL, Twisted Wedge TrickFlo HDs, World class T5, BBK fender cold air induct., 70mm TB,Edelbrock performer Intake, aluminum Drve shaft, 3.55 Gears, Long Tube Headers to Flowmasters.

03-29-2002, 05:45 PM	#2
sn95gt19 motors done......woohooo Join Date: Mar 2002 Posts: 799	i would check the ground for the tach

03-29-2002, 06:40 PM	#3
RoadWarrior Registered Member Join Date: Apr 2000 Location: Edmonton,Alberta,Canada Posts: 317	You might need to get a tach adapter.