99 specific ignition question
 

I recently came across 4 LS truck coils including the wiring connector pigtails for all 4. Currently running ms2pnp and wondering if I need to do anything special to retain the tach signal?
I already have the wiring diagram to hook everything up, is it as simple as it seems, or will I need to open up the ms/run additional wiring for the tach?

skank you very much,
love Flounder

Depends. If it has a tach out from the factory ECU you do nothing. If it didn't have a tachout on the stock ECU, you steal the IGF signal at the ECU connector call it tachout and splice it into the tachout at the gutted factory igniter.

I guess what Im asking is does the '99 have that feature?

my ms2pnp shows
"tacho output enabled" ON
"output on" TACHOUT
"speed" NORMAL

if this is my current setup, is it as simple as wiring in the new coils and adjusting the dwell?

If you wire up the GM coils properly, you will not lose your tach signal and you won't need any special, extra wiring. I had GM coils on my 99 with a mspnp2 and the tach worked just fine.

Thanks MT.net!
gonna install over the weekend, i'll post pics :eek3dance

did you run a resistor?

Nope, I ran mine "raw".

I haven't uploaded pics from my phone yet, but wow, what an improvement! After wiring them up, and tweaking dwell a bit by following settings found in another thread, it fired up first crank.
First test drive, and all my problems are gone! No more hesitation in high boost and my tires won't stop spinning lol I've been chasing this issue thinking it was the detonation and went real conservative with my timing above 14psi, looking forward to picking up some gains thru advance.

thanks for the spoon-feed, pics later...