I would say, one of the most important things to do is adjust your valves. Issues there may just show up as a slow degradation of power on a carb, but can cause real fuel issues with an O2 sensor. It tuned out much better after doing my valves.
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This is an understatement. The sniper hates blow-by. I'm on my 3rd O2 sensor already. I have a spare head ready for a valve job.I would say, one of the most important things to do is adjust your valves. Issues there may just show up as a slow degradation of power on a carb, but can cause real fuel issues with an O2 sensor. It tuned out much better after doing my valves.
A little more detail...Got it figured out thanks @MoaByte it was the vaccum advance but now running into the issue of it not liking to stay running when cold. Anyone else have those issues?
Very well put.Just an FYI, or, maybe just my opinion/observation.
This product is marketed as self learning and plug and play. It sort of is when compared to older Megasquirt and such, but, it's not AI. It doesn't magically know whats going on with the condition of the motor. It shows up with a fuel map that is safe to the manufacturer, that is, it's rich so they don't damage our motor.
For it to learn, it assumes the entire motor and all the sensors are functioning properly. If you do not know how to manage a simple carb motor, and keep it maintained and running smooth, and you toss this on a motor that has a craptasic carb, worn valves, old distributor, vacuum issues etc, no only isn't it going to run smooth, your issues are going to get worse as units keeps trying compensate and learn. It'll be a death spiral. It's not a magic bullet for an engine with 200k on the clock. If cylinder 6 has a poopy valve, it doesn't know how how to ignore the f'd up O2 reading its going to get like an analog carb, it's going to try to correct it, and it will fail, and it will learn to gt worse.
This seems to be the official Sniper thread so I'll ask here. I've fouled another O2 sensor after just a few weeks. It was fine until this morning. It was 20° F and on initial start up, the engine fired, stumbled, and died. Cycled the ignition, stumbled to life and I walked away to let it warm a bit. (I don't like driving it until coolant temp is above 70°). Anyhow, I got distracted and let it idle for probably 12 minutes or more before I jumped in to drive to work. AFR was reading 38:1 but black smoke out the tailpipe indicates a fouled O2 sensor. What did you all set your target AFR's to?
ill download and take some screen shots of my settings when I get home. I'm not stock, but unless you did something really wacky, I cant see that killing an O2. THink about it, you're getting "normal" reading and its running fine, why would an o2 s*** the bed fro the exhaust?This seems to be the official Sniper thread so I'll ask here. I've fouled another O2 sensor after just a few weeks. It was fine until this morning. It was 20° F and on initial start up, the engine fired, stumbled, and died. Cycled the ignition, stumbled to life and I walked away to let it warm a bit. (I don't like driving it until coolant temp is above 70°). Anyhow, I got distracted and let it idle for probably 12 minutes or more before I jumped in to drive to work. AFR was reading 38:1 but black smoke out the tailpipe indicates a fouled O2 sensor. What did you all set your target AFR's to?
my angle sensor is a little bit over perpendicular, and i have 3-2-1 headders so its under the driver where i could get a drill in there. further away than ideal. i was too lazy to drop anything.This seems to be the official Sniper thread so I'll ask here. I've fouled another O2 sensor after just a few weeks. It was fine until this morning. It was 20° F and on initial start up, the engine fired, stumbled, and died. Cycled the ignition, stumbled to life and I walked away to let it warm a bit. (I don't like driving it until coolant temp is above 70°). Anyhow, I got distracted and let it idle for probably 12 minutes or more before I jumped in to drive to work. AFR was reading 38:1 but black smoke out the tailpipe indicates a fouled O2 sensor. What did you all set your target AFR's to?
I keep them stock settings.
Where is your O2? Maybe it’s at a downward angle and it’s getting moisture?
Ever since I began taking the O2 way downstream and clocking at 45* I’ve not had a single O2 go out in any of the vehicles I own or built
How far is "way downstream"?
If a header, 6” down from the collector.
If a manifold in the flat spot just past where the EGR tube goes up
An exhaust leak, even a pinhole, upstream anywhere in the exhaust will throw the O2 sensor off and it will run rich to compensate for the extra oxygen in the stream. Though the engine doesn’t need it the sniper believes there’s a need to enrich the mix. This causes a swift decline in the 02 sensor. As this issue persists your cylinders and pistons are likely getting very choked up with carbon which will lead to hot spots and detonation which causes even worse conditions in the exhaust flow and the 02 sensor sends more bad signals throwing the sniper off even further. I’ve learned the hard way that it’s not good to put a sniper on a tired engine. It will be sweet on a fresh rebuild, but I’m still wondering how it will handle extreme cold. I’m seriously thinking about going back to a carburetor after all the troubles I have run into. Take a look at my thread and you’ll see the pictures of my head and cylinder after running the sniper in a rich condition for too long.This seems to be the official Sniper thread so I'll ask here. I've fouled another O2 sensor after just a few weeks. It was fine until this morning. It was 20° F and on initial start up, the engine fired, stumbled, and died. Cycled the ignition, stumbled to life and I walked away to let it warm a bit. (I don't like driving it until coolant temp is above 70°). Anyhow, I got distracted and let it idle for probably 12 minutes or more before I jumped in to drive to work. AFR was reading 38:1 but black smoke out the tailpipe indicates a fouled O2 sensor. What did you all set your target AFR's to?
Good point. I may need a smoke machine.An exhaust leak, even a pinhole, upstream anywhere in the exhaust will throw the O2 sensor off and it will run rich to compensate for the extra oxygen in the stream. Though the engine doesn’t need it the sniper believes there’s a need to enrich the mix. This causes a swift decline in the 02 sensor. As this issue persists your cylinders and pistons are likely getting very choked up with carbon which will lead to hot spots and detonation which causes even worse conditions in the exhaust flow and the 02 sensor sends more bad signals throwing the sniper off even further. I’ve learned the hard way that it’s not good to put a sniper on a tired engine. It will be sweet on a fresh rebuild, but I’m still wondering how it will handle extreme cold. I’m seriously thinking about going back to a carburetor after all the troubles I have run into. Take a look at my thread and you’ll see the pictures of my head and cylinder after running the sniper in a rich condition for too long.
The Sniper replaces the carburetorCan I run the original carb for a Sniper? Also how much of a MPG improvement avg one can see?