So in the fall of 2025, I added the sniper to my build, and it's been a constant battle with reliability and driveability. I don't really trust it for any drive longer than 30 min. Often, I can't make it back from the gas station across the road without nursing it back to the garage.
Most of the issues were pretty simple to diagnose and fix - a few bad grounds, an exhaust leak, and an issue with ignition. Although these fixes solved smaller issues, the overall issue- reliability- remains. When it works, it drives great; then the issue randomly will appear, and it's undriveable again. Basically, the AFR drops to the 9s - not getting enough fuel. I placed a gauge on the fuel line, and it's pinned at 60 psi. When this first started to happen, I found the ground to the fuel pump needed adjustment. Soon the fuel pump itself failed. I replaced the pump, and the issue appeared to have been resolved.
After a few weeks, the AFR was erratic, jumping up to the high 20s then back to the 9s. The fuel pump seemed happy, so I looked at the O2 sensor - cooked. Replaced the O2 sensor and looked for an exhaust leak. Found the leak with soapy water and a leaf blower up the tailpipe. Again, fixed the issue and it ran great for about 3 weeks.
This past week the issue has returned. Erratic AFR; engine is struggling to stay running. Still starts and idles great, but under load, it struggles. I looked for another exhaust leak with the soapy water and smoke this time; didn't see any leaks. Vacuum is at 18-19 Hg. My AFR settings are Idle 13.0, Cruise 14.5, WOT 13.5.
It feels like there is still an exhaust leak, but I do not see any evidence of one. I am not sure what else to look for and am hoping those with some experience troubleshooting these things might chime in. I'm very close to ripping out the Sniper system and putting the carb and original fuel system back.
Most of the issues were pretty simple to diagnose and fix - a few bad grounds, an exhaust leak, and an issue with ignition. Although these fixes solved smaller issues, the overall issue- reliability- remains. When it works, it drives great; then the issue randomly will appear, and it's undriveable again. Basically, the AFR drops to the 9s - not getting enough fuel. I placed a gauge on the fuel line, and it's pinned at 60 psi. When this first started to happen, I found the ground to the fuel pump needed adjustment. Soon the fuel pump itself failed. I replaced the pump, and the issue appeared to have been resolved.
After a few weeks, the AFR was erratic, jumping up to the high 20s then back to the 9s. The fuel pump seemed happy, so I looked at the O2 sensor - cooked. Replaced the O2 sensor and looked for an exhaust leak. Found the leak with soapy water and a leaf blower up the tailpipe. Again, fixed the issue and it ran great for about 3 weeks.
This past week the issue has returned. Erratic AFR; engine is struggling to stay running. Still starts and idles great, but under load, it struggles. I looked for another exhaust leak with the soapy water and smoke this time; didn't see any leaks. Vacuum is at 18-19 Hg. My AFR settings are Idle 13.0, Cruise 14.5, WOT 13.5.
It feels like there is still an exhaust leak, but I do not see any evidence of one. I am not sure what else to look for and am hoping those with some experience troubleshooting these things might chime in. I'm very close to ripping out the Sniper system and putting the carb and original fuel system back.
