Sniper and ground wires.
Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
Sniper and ground wires.
Well it has been a while since I started on my Sniper install on my 68 with a ZZ454. I moved fuel pump relay to the battery box and trigger the pink wire through a relay (also in the battery box) connected directly to the battery. 12 gauge + and - main power wires are connected to the battery also. I have braided metal shield over power and ground wires and a separate shield over the pink wire. These are grounded directly to the battery. I have routed all wiring is as far as possible from ignition wires. All of this in an effort to eliminate electrical noise. I have paid very close attention to the battery to frame ground wire and actual connection point as well as the frame to engine ground. I am going to add a direct alternator to frame ground. For those who have installed the Sniper, have you found that other grounds are needed? Any other advice before I finish up and try the first start?
Racer
Joined: Jul 2018
Posts: 411
Likes: 232
From: central Florida
2023 C3 of the Year Finalist - Modified
2020 C3 of the Year Finalist - Modified
2019 C3 of Year Finalist (track prepared)
Well it has been a while since I started on my Sniper install on my 68 with a ZZ454. I moved fuel pump relay to the battery box and trigger the pink wire through a relay (also in the battery box) connected directly to the battery. 12 gauge + and - main power wires are connected to the battery also. I have braided metal shield over power and ground wires and a separate shield over the pink wire. These are grounded directly to the battery. I have routed all wiring is as far as possible from ignition wires. All of this in an effort to eliminate electrical noise. I have paid very close attention to the battery to frame ground wire and actual connection point as well as the frame to engine ground. I am going to add a direct alternator to frame ground. For those who have installed the Sniper, have you found that other grounds are needed? Any other advice before I finish up and try the first start?
Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
Just a quick follow up. Yesterday I finished the install and attempted the first start. Fuel pressure was a solid 60 psi and I had no leaks. After running the wizard I turned the key and it fired almost instantly, but died. I tried this a couple of times with no start. I checked the No Start flow chart and while looking at the gauges I realized I was getting no tach signal. Found the connector on my HEI had come loose. After reconnecting, it started immediately. I had to make an adjustment to the throttle adjustment screw. After it warmed up I reset the IAC as directed. I drove it for about 15 minutes and am happy to report that it ran great. Throttle response was crisp, acceleration was smoother. The best thing was that when I pulled back in the garage my wife said it didn't stink like it used to. So far I'm thrilled with the Sniper.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
New fuel feed line? I feel the 50 year old fuel line designed for slight vacuum is not a good candidate for 60 psi fuel feed. It is fine for a return line, but if it leaks, it sprays fuel all over the exhaust at 60psi while still runs. If same line leaks while feeding an engine mounted fuel pump, carb sucks air instead of fuel and engine stops.
Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
New fuel feed line? I feel the 50 year old fuel line designed for slight vacuum is not a good candidate for 60 psi fuel feed. It is fine for a return line, but if it leaks, it sprays fuel all over the exhaust at 60psi while still runs. If same line leaks while feeding an engine mounted fuel pump, carb sucks air instead of fuel and engine stops.
