I have a 2001 sentra that appears to be running extremely rich. New spark plugs it runs great, give it a few days around town and they look like crap again and with that it bucks at speed off and on, idles like garbage.
Now for the storyand what’s been done. I got it in July, it ran like this then. After changing injectors, MAF sensor, and O2 sensors. Scan tools showed the above was bad. Now, there is no check engine light but it’s still running rich. We also found that the gas was tampered with, no clue with what but it was bad and not cleaning up. Because of that, I also replaced the tank and the unit in it with pump, filter, regulator, and suck in it. I got the tank from another car that’s known good after an extreme cleaning and the car it came from, with the old tank in it, cleaned well, runs perfect.
I’m running out of ideas, with new spark plugs, it runs perfect for a couple days then they get fowled, it looks like running very rich, on all 4 of them though one did look a little worse than the rest. Does anyone have any ideas what I should look at next? idle is right where it should be in RPM. I believe the AC compressor is locked but that shouldn’t have anything to do with it.
Other unrelated things I notice but maybe it means something to someone, the headlights dim and come back as if the alternator is going but that’s new, the concerning problem is not and voltage looks fine so far with a volt meter. AS I said AC compressor appears locked up but I just haven’t used the heat or anything yet so that’s not an issue. It also starts hard when the spark plugs get fowled but not with clean ones in there so I think that’s a result, not a cause. I think everything’s OK electrically, I want this fixed before winter sets in. Anyone have any ideas? I have another car ti pickparts from, I can’t register it at this time so I can pull parts off it to try but being an extremely active 1 car family I need this thing straightened out before something serious happens because of it. Thanks, John