Sniper 2 installation tps help
Thread Starter
2nd Gear
Joined: Dec 2025
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Sniper 2 installation tps help
Original motor in grandpas 1986 vette with the 4+3 manual blew up after he passed. Fast forward 12 years I bought a performance crate engine for it and switched to a carb and got it back on the road but didn’t have the overdrive working I think because there is no tps sensor. I’m now installing a Holley sniper 2 system and I believe it has a single tps wire while the original connection on the car has 3 wires. Has anyone done this or know what needs to be hooked up for the ecm to receive a tps reference. I think one is ground one is 5volt and the other is to ecm. I’m guessing just ecm wire to sniper system but I’ve been wrong more times in my life then I have been right. Any help is appreciated.
Team Owner
Joined: Jan 2003
Posts: 20,277
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From: Summerland B.C. Canada
Melting Slicks
Joined: Mar 2002
Posts: 2,874
Likes: 764
From: Sligo PA
The ECU in the Sniper 2 has a few basic I/O. You could pretty easily use an output to control the overdrive just like the factory did. You could even wire the overdrive button to an input and have it work too.
Just in case you didn't know the factory ECU controls the overdrive. I could be wrong about the details but I think It won't allow it to shut off until you are at operating temp, and over a certain throttle position. If you carb swapped the car and removed the factory ECU then this is why it's not working. But like I said the Holley can do that for you.
Just in case you didn't know the factory ECU controls the overdrive. I could be wrong about the details but I think It won't allow it to shut off until you are at operating temp, and over a certain throttle position. If you carb swapped the car and removed the factory ECU then this is why it's not working. But like I said the Holley can do that for you.
Drifting
Joined: Jun 2020
Posts: 1,680
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From: Stay dangerous my friends
Best way to control the overdrive on a 4+3 is with a simple latched button/switch for the overdrive solenoid. The ECM was pretty crappy for controlling it anyway, and had to disable it every time I started driving.
