Need help with tach hook-up

TurboToy94 · Post by **TurboToy94** » Tue Aug 29, 2006 8:25 am

Hey guys new to the board and MS, but a good friend of mine helped me install a MS1 V3.0 on my 1994 Toyota 4x4 pickup with the 22RE and a turbo set-up, the MS has performed awesome to keep the stock motor in tune with 15# of boost, but my problem is my truck has the full instrument cluster, which is kinda rare for a 4 cyl. regular cab truck and since the MS install I have no tach. I am using a 6AL box and have dealings with MSD tech on this but the last time they had me "try" something it fried a zener diode in the MS.

Basically we ran the two distributor wires to the MS and the spark output to the 6AL box and from the 6AL right to the factory coil, completely by-passing the factory ignitor assembly. The ignitor has a black wire that feeds the factory tach and the A/C amplifier and any "tach" source hooked to this wire will kick on the A/C, but will not run the tach? I can hook any aftermarket tach up and it works just fine, and my cluster is still good, I took it out and checked on a stock truck?? I have all good connections, I am lost at this point....

Thanks in advance,
Rick

elturbonitroso · Post by **elturbonitroso** » Tue Aug 29, 2006 4:37 pm

try this and let me know if this work for you for some people is working very well http://megasquirt.sourceforge.net/extra/tachopin.html

sparkandfuel.com · Post by **sparkandfuel.com** » Tue Aug 29, 2006 5:16 pm

worked great for my friend running 4 COP (straight up cop, not wasted/cop) on his 4agte 20 valve.

TurboToy94 · Post by **TurboToy94** » Tue Aug 29, 2006 9:44 pm

elturbonitroso wrote:try this and let me know if this work for you for some people is working very well http://megasquirt.sourceforge.net/extra/tachopin.html

Thanks alot for the link, as soon as I get my MS back up and running I will be very much in hurry to try that. Hopefully it works, it's the best plan I have seen yet!!

I'll keep you posted as to when...??? I get my MS fixed, like I said the last way a MSD tech had me hook up a tach adapter and the 6AL box it fried the diode at location D8, which is a 22V zener diode, that goes to pin 30 and goes straight to the white wire on the 6AL box, I installed a new diode but the truck still won't start?? With the laptop hooked up it shows all the inputs like it should, when I crank the truck over is shows the RPM's and such but no signal to the 6AL box as to when to fire. I tested the 6AL and it is still good, I'm kinda lost, and it sucks because this truck is my daily driver. The diode I installed checked one way at about .606 on my diode checker and nothing the other way, however after just cranking the truck and getting no start, with the MS torn back down the diode measured .667 BOTH ways, so it must have popped again and I don't know what else is bad, or what to do at this point, so any help with that would be....very helpful!! HA

Thanks guys,
Later

TurboToy94 · Post by **TurboToy94** » Mon Sep 18, 2006 8:10 pm

Hey guys I got the truck running again but I tried hooking up the tach but nothing I do seems to work. I have a good friend that is a MS freak helping me but we are kinda lost at this point. This week I'm am going to "borrow" a tach signal from a friends stock Toyota to see if my tach even works anymore, I might be chasing my tail if tring all these things hasn't fried it already. Then I'll be mad, my truck is one of few 4 cylinder trucks that has the full cluster and it's not cheap from Toyota!

Later