4l80e tach signal

[TagAllen]

I installed but have not test driven my 4l80e. On a stock 95 TBI system if it came with a 4l80e how would the 4l80e get the tach signal? Such as would the computer get it via the purple wire with white stripe?

 

[stutaeng]

I don't know much about the TBIs, but on the Vortecs the tach comes from the camshaft position sensor. You are referring input/output shaft speed sensors on your 4L80s transmission, and I don't think either of those would give you tach output. Both input and output shaft would be turning at a different rate than the engine, depending if you are stopping and what gear you are in.

My brother has a C1500 350, and I think he added an aftermarket tach. I think he tapped into some white wire on or near the distributer? There's a way to do it...

 

[TagAllen]

I hooked up a ISS on the 4l80e and pinned it into my TBI computer. I know in my reading I have done it says a tach signal is needed to operate it along with TPS CTS VSS. So where does the computer normally aquire that tach signal if it the truck came stock with the 4l80e.

 

[TagAllen]

BTT

 

[LC2NLS6]

I'd have to go look to double check, but I installed a Holley sniper EFI, and ran an output signal tach wire from my hyperspark setup back to my factory tach lead that is on the factory TBI harness which used to go to the factory coil. It seemed to work as my dash and factory controller runs the 4L80E (1993) trans and the holley runs the engine.

 

[TagAllen]

well thank you. So I probably have it covered then. Once my driveshaft Is done I should find out quickly.

 

[Schurkey]

MichaelGot reported.

 

[kris72079]

I'd have to go look to double check, but I installed a Holley sniper EFI, and ran an output signal tach wire from my hyperspark setup back to my factory tach lead that is on the factory TBI harness which used to go to the factory coil. It seemed to work as my dash and factory controller runs the 4L80E (1993) trans and the holley runs the engine.

This post is a little old, but hoping I get a response! I’m installing a Sniper 2 system with a Hyperspark ignition this weekend on my 1993 C3500. I planned on using the TPS and tach output from my sniper as an input to my OE PCM so I can continue to use it as a trans controller. It looks as though you did the same? You had no issues in doing so? I contacted Holley and they said they cannot confirm or deny it will work as they don’t test functionality with stock components, only aftermarket. Hoping you can confirm!!!