After-market digital tach installation???

[jtybt]

I just got a 2" digital tach for the boat.(Merc chev V8) I also installed the Delco (voyager)EST ignition system. My shop said some tachs require a filter with electronic ignition. Tach instructions says to get installation info from ignition system Mfg if using an aftermarket ignition system. I can't get an answer from Delco. Seems not many people know much about their products...just like calling Merc.

Original ignition was points but I swapped for TB IV and now to EST. The OEM tach went out so I have an analog aftermarket tach that never was accurate. I'm hoping this digital tach is accurate

I just didn't get instruction with either the EST instalation material dealing with the stock tach or the Digital tach material dealing specifically what needs to be done.

 

[dr_bowtie]

Re: After-market digital tach installation???

what specific tach did you get....

the reference wire on the ignition is where the tach wire hooks...you may need the wiring diagram to see which wire on the ignition is the reference wire...

What coil(s) does the new ignition use?

EDIT: a little info on filters and how to build one...

http://www.camaros.net/techref/electrical/tachfilter/

 

[jtybt]

Re: After-market digital tach installation???

This is the ignition coil. The tach lead is already hooked to my aftermarket tach that isn't very accurate. I wanted to just mount and splice into the dash tach and mount it next to it.

I wanted feedback before I hooked up the tach tomorrow.

I'll read the filter link.




AHA!
I'm off to Radio Shack! Thanky.

 

[jtybt]

Re: After-market digital tach installation???

Forgot to put up a link. This is the coil...

http://cgi.ebay.com/ebaymotors/Mari...8c1978fd&_trksid=p4506.c0.m245#ht_3586wt_1038


And I found this


http://cgi.ebay.com/ebaymotors/GM-E...e1ae86e2&_trksid=p4506.m20.l1116#ht_966wt_718

If you read down, it says 9* base and 18* advance for 27* total.


Pretty good...that's where I have my base set at without being able to take it out to get the higher RPM advance readings.


OH YEAH! Already picked up the resistor and capacitor.

Thanks again, Doc! I owe you.

 

[dr_bowtie]

Re: After-market digital tach installation???

Same distributor as i have in my truck...Thats the common TBI distributor...the jumper wire is just the wire that jumpers it for non-ECM use...non reference mode...

the pre-86 large cap HEI can do the same thing by jumping the green and brown wires...

does that cap have a moisture seal...?

just curious if that is the auto version or how it is sealed if it is the marine version.....

 

[jtybt]

Re: After-market digital tach installation???

That's the thing. I got it on Ebay and the coil bracket doesn't mount to any particular holes and the cap looks just like the auto version...no seal. It has one screen on the base plate. I had the sneaking suspicion this kit was 'put together' but for the price, I now have two complete ignition systems.( Still got the TB IV)


I put di-electric on the edges of the cap anyway.

 

[dr_bowtie]

Re: After-market digital tach installation???

i'll bet it is the 86-94 auto version...I would grease the vent too then...?

those distributors are only 60.00 at Advanced Auto part or Autozone...

so if you can make the Jumper harness you could make a killing...the coil would bolt behind the TBI on a car/truck but do any boat use that coil...?

EDIT: here is a link to an aftermarket Tach Filter...just because the factory GM Tach Filter used on Camaros and Vettes has been discontinued....

http://www.marshallinstruments.com/products/9219.cfm

 

[jtybt]

Re: After-market digital tach installation???

The parts for the filter cost about $2.35 but that included a 5 pack of the resistors.

Tested out the little digital tach and she matches up to a $500 Snap-on and a new $130 Innova Advance/tach timing light...Pretty good for $12(of course the shipping was $18)(but that's another story)

 

[dr_bowtie]

Re: After-market digital tach installation???

sweet...glad it all worked out for you....