so i did the old 305 tpi to 350 carbed swap on my 1992 z28. i took out the ecu and harness..
i read that the ecu controls the speedometer and tach

i was planning on doing all new gauges. (glowshift)


but all my other gauges are working...if i could get get these two working i would just do leds to make them look purdy.

but if i cant, im not just gona buy two gauges it look half ***, i would buy all 5 so it looks nice. but its like 400 bucks...

therefor please tell me i can fix these twooo!!!!!!!!!!!


thanks
-matt

Speedo should be working fine. NONE of the gauges are connected to the ECM in any way (my 1992 car has no ECM and all gauges fine). So I'm not sure what the issue is there - buit it's not ECM related. Did you disconnect the wires at the tranny tailhousing for any reason and forget to reconnect?

Tach connects to your new vacuum advanced distributor - you have to cut the distributor connector and crimp terminals on the wires only 2 get connected, but don't remember wire colors - there's alot of threads here about it.

From the EFI to Carb tech article:

The old coil has 2 wires going to it, you will need to connect these wires to the connectors on the new coil. If you can find the proper plug assembly in a store or junkyard for it then great, I simply used two crimp on female spade connectors to clip them onto the new coil. It will have only 2 connectors to go to, the red/pink wire goes to the one labeled BATT, and black wire goes to the connector labeled TACH.

https://www.thirdgen.org/carbswap

sweet. the only thing i got the car gutted..so i dont know how factory harness goes. i just know its out..i only have drivers side wires and i have these two


summit racing box SUM-850600summit racing SUM-850001R HEI distributor (trigger style-magnetic)(advance type- vacuum and mechanical)

saving

I have no idea what a SUM-850600 is, doesn't come up on Summit's site. But the dizzy is fine.

Probably

http://www.summitracing.com/parts/SUM-850610/

Cheap version of a MSD 6A

well back to my speedo, i looked at my old ECU and harness that i had in my shied. the PURPLE/YELLOW wire connects to the back of my tranny, it goes into the ECM and then the ECM goes to the gauges. i did alot of research and the VSS is built in the tranny on the v8 TPI'S therefore i dont need that yellow VSS box. so i cut the yellow/purple wire from the harness that goes into the bigger connector in the passinger side wall, then goes into the ecm. i now have the yellow/purple connecter that plugs into the tranny. but now where do i connect the purple and yellow/wire for the speedo to work??????