MSD Upgrade No Tachnometer

[Arlo Cooper]

Hi guys,

 

I have a small problem that I am so sick of and can't get my head around.

 

I did a MSD CDI upgrade a few months ago, the Streetfire version, and I can't get the tach to go. 

I have read every MSD Streetfire upgrade thread, and Noone has needed to use a tach adapter. 

Everyones tach works fine with a direct feed from the gray wire. But for some reason mine does not. I have bought and tried the tach adapter however. 

Does anyone have any suggestions I can try? I will take any suggestion..

I have tried everything but hopefully I have missed something. 

I am running a bluetooth 123 dizzy, MSD blaster 2 coil. Everything else seems to work fine. Please helpppppppp

 

Appreciate every second of your time,

 

Arlo.

 

[M2M3M3]

your other thread seemed to have a lot of useful info in it.  you didn't reply to it.

 

 

have your checked to see if your tach is still functional?

 

[Dudeland]

I have the same setup. You need a tach adapter.

MSD 8910 I think is the model.


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[Dudeland]

I didn’t see the street fire part. Sorry. I can check mine to see how it is wired it would help, but it is a regular 6AL. Post some pics of the wiring. I am sure someone here can help.


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[tashakes]

I posted my experience with a very inexpensive adapter after frying a couple of the more costly ones. 

 

Autosportlabs tach adapter install

 

Four years later still working perfectly, hope this helps. 

Edited November 27, 2018 by tashakes
Link edit

[Simeon]

Been trying to reply to this for days.  See my blog post for details about how the tacho works and why you need an adapter. The adapter is effectively a fake coil that’s purely there to make an inductive field and then collapse.  This is wired, one wire to the switched battery feed and the other connected in parallel at the point the black wire from the 123 and the white wire to the MSD.  There should also be a diode to connect in there somewhere as well. Looking at the MSD technical manual, it identifies two different part numbers. Which one do you have?

 

 

Wiring diagram 

 

 

Blog post

 

https://www.bmw2002faq.com/blogs/entry/524-ignition-investment-updated/

Edited November 27, 2018 by Simeon

[nbristow01]

How are you liking the BT 123 Dist?

[Arlo Cooper]

Hi guys, thanks for the replies.

 

The tach adapter I have is 8910.

But that wiring diagram is not at all what I got with my tach adapter. 

 

I havent bench tested the tach. Well I have. But I haven’t been able to get it to work so I was going to swing by the tach shop just to double check there is nothing wrong with it. It was working before I added the cdi box.. 

 

I shall read into that blog post Simeon and try a few different things. 

 

The 123 is really nice. I bought a bad dizzy from IE and it was being a pain and everything else in the car I have done really as well as I could, so it seemed weird not to get the 123 it was just abit expensive at the time. However for what it is. It is actually extremely cheap. I love it. Sure the price is expensive relative to other distributors but it isn’t at all in anyway relative to any other distributors so no real comparison. I’d recommend to anyone. Even the build quality is Lovely. 

[Arlo Cooper]

Bench tested the tacho using other means to confirm the tachometer is not working any longer.

 

Is there anywhere anyone knows of to find a schematic to try and fix it? I doubt I'm going to be able to find another one. 

Has anyone ever done this before? I can't see it being to hard surely something has just blown. 

 

Thank you. 

[Simeon]

2 hours ago, Arlo Cooper said:

Bench tested the tacho using other means to confirm the tachometer is not working any longer

 

What was your method here? I would check the continuity of the wiring between the old connection at the coil and the connection with two wires that used to connect to the distributor/ condenser. This is then through connected to the back of the tacho.  Definitely worth checking this before ripping into the tacho. Beyond that, it is full of components like resistors and capacitors.  If you can identify which ones may have failed, then I guess they will be relatively easy to replace.

[jimk]

When my MSD tack adapter bit the dust and melted on the way back from the MidAmerica02fest and took out the tach at the same time, I dropped the tach off at Delux Speedometer in Denver.  The guy replaced the board with a new style that accepts the square wave input signal.  $75 and I'm out the door.  He said they convert many collector tachs.

[Arlo Cooper]

Bench test method was taking it down to Auckland Speedometer Services & Repairs, small little shop but very nice people & service. I'll have a browse around.

 

Oh that is interesting information. I might look into that, thank you. 

[Arlo Cooper]

Simeon.

 

I have purchased a new tachometer, which was bench tested before I got it so I knew that it worked. And I have wired the tach adapter in your wiring exactly as it states. Red with the 12v side and the white with the white dizzy/ignition box wire with the diode & then to the tach and it hasn't done anything. I then metered the connector to find 12v?? I hope I haven't fried this new tacho from that voltage. The grey wire seems to be spitting a small varying amount of voltage which increases with revs still. I really don't get it. Any pointers?  

[tashakes]

See my comments 8 posts up, give $15 a chance, I think it will work.

[jimk]

40 minutes ago, tashakes said:

I think it will work.

I have one on the shelf.  It only works on waste spark two circuit coils and two inputs.  His is a MSD that triggers the tach with each spark on one lead wire.