Engine stumbing (or 'missing')
For about 3 months now, I had a problem with my O2 sensors where they all read that they were bad, but the car ran fine. Lately it's been getting colder, and the engine started acting strangely, so I figured it was time to do it. I changed out the driver's front oxygen sensor (which was bad) but the passenger side had too short of a cable and wouldn't work, but looked fine. So I disconnected the battery to reset the codes. I figured if the o2 sensor code came back, I would replace it - if not, I wouldn't worry about it. I hadn't been driving the car a lot at this point.
After reconnecting the battery, it ran rough, which I figured "Hey, that's normal" but then it started getting REALLY bad. When you would step on the gas, the engine would bog down pretty bad, and then suddenly rev way up. I took it to Autozone and had the codes read again. (Previously, it was just 4 bad o2 sensors and 4 bad o2 heater circuits) Now there were only two o2 sensor codes, but there was also a code for "engine misfiring" and "running rich". He said what's probably happening is that one of my cylinders wasn't firing, (leading to misfiring) and since it wasn't igniting the fuel, then it was running too rich (too much unburned fuel in the gas). So I changed the spark plugs. That made all the rest of the cylinders run better, but it was still stumbling (although not quite as badly as before) so I changed the plug wires, which had no effect. So today, I figured I'd try one last thing, and I put a new ignition coil on it, which ALSO had no effect. I also thought "Maybe it's bad gas" (wishful thinking, I know) so I put in some Chevron Premium and STP Fuel Injector Cleaner. Which again, made the car run better, but didn't stop it from stumbling.
So now, after all that, the only difference is that the Thunderbird is still broke, and now I am too. Does anyone have any ideas?
The only other thing I can think of is that maybe it's possible that it's missing BECAUSE there's too much fuel, not that there's too much fuel because it's missing. Like something is telling the computer to send more fuel, only now there's so much that it's flooding a cylinder or something.
Please let me know if anyone has any tests or suggestions that might be causing this. Otherwise, my car is going to sit in the backyard until I have enough money to take it to the Ford house so they can tell me what's wrong.
1997 Black T-Bird LX 3.8, custom painted interior, hand stitched vinyl backseat, oversized K&N cone filter, air silencer removed, painted some engine components, door solenoids for shaved door handles, Black Widow security system, wired to open Driver's door when disarmed, Dynomax 2.5" exhaust, battery box moved to trunk, custom grill inserts