Turbo6inKY Posted July 9, 2005 Share Posted July 9, 2005 This post is an effort to spare others the confusion I endured trying to figure out how to get my Z's original tachometer working with my MSD 6AL. A cursory search of HybridZ uncovered similar confusion, these two threads are prime examples: http://forums.hybridz.org/showthread.php?t=77434 http://forums.hybridz.org/showthread.php?t=77651 Most people seem to just dump the original tach, but mine was still working fine, so I saw no reason to toss it. New 5" tachometers are a hundred bucks. The tach adapter from Summit is less than fifty. Obviously, the tachometer signal on the MSD is something entirely different than the current triggered signal the OEM four-wire inductive loop thingy. The solution is an MSD Tach adapter. The confusion I ran into was which one to buy, and how to wire it, as the Z is just a tad different than the examples in MSD's diagrams, and all the people cheap enough to not just buy a compatible tach seem to be very poor at documenting how they get things to work. The tach adapter you need is the 8920. NOT the 8910. To wire it up: Find the two ends of the tach inductive loop over near the coil. One wire is green/white, the other is black/white. I advise you to use something to check continuity and make sure you have the correct two wires, as they really aren't two wires, they're opposite ends of the SAME wire. Remove the 8920 tach adapter from the package. Throw away the instruction sheet. Neither diagram applies to the Z. It has four wires coming out of it: Black - ground white - trigger Red - option1 violet - option2 Now, to get the tach working: 1. Take the black/white wire near the coil, and hook it up to an ignition switched 12V (hot when key is on). 2. Run the RED wire from the tach adapter and connect it to the green/white wire. 3. The white wire from the adapter goes to the MSD's tach output. 4. The black wire goes to ground. That's it. That's all there is to it. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 11, 2005 Share Posted July 11, 2005 I have that tach adapter and still wasn't able to get the stock tach working, even when I had the N/A motor with ZX distributor. I'm just curious though, would this exact same wiring setup apply to the turbo motor if installed in a 240z? I've already got an autometer tach but wouldn't mind having the stock tach working. Quote Link to comment Share on other sites More sharing options...
Thumper Posted July 11, 2005 Share Posted July 11, 2005 I was able to hook up the stock tach to the tach output on the msd 6al. So I didn't need an adapter. Quote Link to comment Share on other sites More sharing options...
72_NorCal_240z Posted March 19, 2008 Share Posted March 19, 2008 This set up atleast got something to register in my tach using the tach adapter and wiring as stated, but at idle my tach says its doing 150-200rpm. any ideas? Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted March 19, 2008 Share Posted March 19, 2008 I was able to hook up the stock tach to the tach output on the msd 6al. So I didn't need an adapter. The '74 and later tach is a point trigger, not current trigger like the earlier tach. Quote Link to comment Share on other sites More sharing options...
72_NorCal_240z Posted March 19, 2008 Share Posted March 19, 2008 The '74 and later tach is a point trigger, not current trigger like the earlier tach. ummm, so? do I take both wires from the tach (green/white and black/white) and connect them to the tach output on the MSD? Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted March 19, 2008 Share Posted March 19, 2008 ummm, so? do I take both wires from the tach (green/white and black/white) and connect them to the tach output on the MSD? Not at all.... read the first post in this thread, that's what needs to be done. Quote Link to comment Share on other sites More sharing options...
72_NorCal_240z Posted March 19, 2008 Share Posted March 19, 2008 Not at all.... read the first post in this thread, that's what needs to be done. I've already done that, and it did work, its just not reading accurately, at idle (900rpm) my tach is reading about 200rpm. before i added the MSD, the tach worked perfectly. the car runs extremely well with the MSD/blaster 2/pertronix set-up, but would like the use of my tach. I apologize if I'm not understanding you properly, I'm just looking for other options as to why the tach would not read accurately. Quote Link to comment Share on other sites More sharing options...
Z8driver Posted April 2, 2008 Share Posted April 2, 2008 On my early Z with a V8, I use the TechnoVersions TachMatch with the MSD 6 trigger signal output as the input, and its conversion from 8:6 to make the tach read correctly. This is with the early Z current-trigger tach, but it works on the later Z voltage-trigger tachs too. Quote Link to comment Share on other sites More sharing options...
JSM Posted April 4, 2008 Share Posted April 4, 2008 This worked perfectly! I just got my stock 73 240z tach working! Thanks so much. Won a new 8920 for $30 off of ebay. Quote Link to comment Share on other sites More sharing options...
MikeyZee Posted April 29, 2008 Share Posted April 29, 2008 Do these insructions apply if I am using the magnetic pickup? I have a ZX dizzy without the e12-80 module in my son's 72 240z. The red and green from the dizzy are connected to the green and violet of the MSD 6T. The switched B/W is hooked up to the switched (red thin wire) from the MSD. The G/W and the other B/W are connected together. I was told By MSD to use the 8910EIS because I am using the magnetic pickup???? The MSD still gives the same output to the Tach connector right? Glad I saw this post!! You guys know everything about these cars!! Thanks, Mike Quote Link to comment Share on other sites More sharing options...
CoastGuardZ Posted March 4, 2013 Share Posted March 4, 2013 Do these insructions apply if I am using the magnetic pickup? I have a ZX dizzy without the e12-80 module in my son's 72 240z. The red and green from the dizzy are connected to the green and violet of the MSD 6T. The switched B/W is hooked up to the switched (red thin wire) from the MSD. The G/W and the other B/W are connected together. I was told By MSD to use the 8910EIS because I am using the magnetic pickup???? The MSD still gives the same output to the Tach connector right? Glad I saw this post!! You guys know everything about these cars!! Thanks, Mike THREAD REVIVAL! This is a question that I wish had been answered, because I am about to dive into this tonight. I just dropped a built L28 into my '72 that I picked up from someone. It already has the ZX dizzy installed and was previously running with this MSD 6AL... I just want to make sure I get the tach right. From what I've gathered so far it sounds like I need the 8920... I've searched through multiple sites and nothing difinitive yet... any input or direction from the gurus? Quote Link to comment Share on other sites More sharing options...
JSM Posted March 13, 2013 Share Posted March 13, 2013 That was what I used. I had the ZX dizzy and MSD 6al too. It was one of the few threads I followed exactly and worked the first time. The car i did that on is wold now. Quote Link to comment Share on other sites More sharing options...
3ryce Posted April 14, 2013 Share Posted April 14, 2013 Is the MSD 6AL required to use with the MSD tach adapter? Quote Link to comment Share on other sites More sharing options...
monster626 Posted April 14, 2013 Share Posted April 14, 2013 The 8920 is the only adapter that I have found to work on our z cars with no issues every time. But when purchased used its hard to tell them apart from the 8910 that looks the same. Quote Link to comment Share on other sites More sharing options...
3ryce Posted April 17, 2013 Share Posted April 17, 2013 So I dont need to get the MSD 6AL to go along with the tach adapter? Also I noticed that the secondary coil sitting on top of the Ignition coil was super super hot, is it normal for it to be hot? Quote Link to comment Share on other sites More sharing options...
3ryce Posted April 25, 2013 Share Posted April 25, 2013 Also my secondary coil, on top of the igntion coil, seems to be getting pretty hot. Is that normal? Quote Link to comment Share on other sites More sharing options...
Apollyon12 Posted June 2, 2013 Share Posted June 2, 2013 Would the MSD unit work for a Crane/Pertronics Ignition? Crane sells an adapter but it says its for newer OBS applications. Quote Link to comment Share on other sites More sharing options...
ksbeta Posted June 28, 2013 Share Posted June 28, 2013 My sincere apologies for digging up something so old, but I could use some help. I'm having the same issue as 72_NorCal... This set up atleast got something to register in my tach using the tach adapter and wiring as stated, but at idle my tach says its doing 150-200rpm.any ideas? Any idea what might cause this? Bad Tach? Bad Connections? Quote Link to comment Share on other sites More sharing options...
ksbeta Posted July 10, 2013 Share Posted July 10, 2013 Lots of tweaking, still no luck. MSD Claims I forgot to cut a loop on the MSD 6A. I didn't. Any thoughts are appreciated. Quote Link to comment Share on other sites More sharing options...
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