teddie300c

Sorry. I have good ground to the bung on both sides. I checked to see if I was getting 12v on the heater by connecting 1 wire to 12v and then attached one probe to the other heater wire while unhooked and then probed to the exhaust.

Injuneer

I'm still not convinced you are using your meter correctly.

I'll take a look at the third data log,

teddie300c

man i can completely understand the frustration with this so i dont think i could say it enough but i really appreciate your help. i think maybe ill get some different 02 sensors. im not real handy with a multi meter but i think i do alright. its kinda hard to find something to compare to online or maybe im just not understanding it right.

Injuneer

The O2 sensors are "working", in that they are no longer stuck above 1.000 volts, but the results are still la big mess.

First, you are correct - the O2 sensors need the ground wire connected. Where did you connect it? That indicates two possibilities:

1 - The Bosch sensors do not ground through the threads/bung like AC Delco sensors do

2 - There is no ground provided at the O2 sensor bung on the headers.

While is seems near impossible for no ground to exist at the bung on the headers, it is remotely possible that the gaskets and corroded bolts are preventing the ground. And, a lack of ground on the headers would also explain why, in the first data log both 1-wire O2 sensors were indicating an open circuit. They apparently had no ground.

Now, with the sensors "working", the closed loop results are a disaster. Bank 1, by the end of the data log, is pouring in a huge amount of extra fuel. The LTFT is maxed out at 160 (adding 25% extra fuel) and the STFT is maxed out at 254 (adding 96% extra fuel. The O2 sensor reading is hanging below 0.300 volts for several seconds at a time, and the average Bank 1 O2 sensor reading is 0.304 volts, when it is supposed to average close to 0.450 volts (Bank 2 is averaging 0.460 volts). The ECM had bumped the Bank 1 injector pulse width to 7.3 milliseconds, vs. a Bank 2 pulse width of 4.6 milliseconds.

Part of that split in the injector pulse widths is the result of a rich condition on Bank 2. The Bank 2 LTFT is 112 (reducing fuel by 13%).

I have never seen anything this extreme in 20+ years of reviewing these data logs. Either the O2 sensors (at least the Bank 1) are faulty, the O2 sensors (at least Bank 1) is wired incorrectly), or there is something causing a huge fuel shortage/lean condition on Bank 1, and there is something causing a significant fuel excess /rich condition on Bank 2. This does happen from time to time, and its often called "split BLM's", but these result are well beyond that.

How does it idle? Is it rough, or smooth? How does the spark plug appearance compare from Bank 1 to Bank 2?

I have no confidence in the O2 sensors, and that limit the ability to find the cause of the major problems. But if it's a wiring problem, simply replacing the sensors with AC Delco sensors is not going to solve the problems..

I did notice that when you first tried to start the engine, it appeared is didn't want to start, and you stopped cranking it after about 1.5 seconds. The battery voltage is dropping seriously while cranking. What happened there?

teddie300c

ok so i have the sensors grounded to an exhaust clamp on both sides. i believe i have a good ground on both as i have checked continuity from there to various places like the bottom of the engine and parts of the body.

it idles ok and a bit rougher when it hits closed loop. could a bad fuel injector cause any of that at all?

i had changed the plugs and wires awhile back and it idled perfectly. i would get out and floor it only for the exhaust to start beating the floor pan and ended up changing the motor mounts and transmission mount. it tried to leave me stranded picking up the motor mounts but i figured it was because of the incline i was parked on but it started doing it more often so i rented a fuel pressure tester after checking my plugs and finding a wet one. it built up pressure like it should and held pressure at an idle but would slowly leak off when i shut the car off. i havent gotten around to testing it again because the only tester they have is the master one and its about 150 to rent.

teddie300c

when i had the bad fuel injector it idled ok untill i put it in gear and tried to move. the way it idles now once it hits closed loop is almost the same except it does it in park and a little worse in gear.

Injuneer

Any issues with fuel pressure should affect both banks of the engine equally. According to the LTFT's you have too little fuel (or too much air) on Bank 1 and too much fuel (or too little air) on Bank 2. That's not a fuel pressure problem. A faulty injector that is not supplying fuel causes the O2 sensors to indicate “lean” and the LTFT's will increase. Ditto with a complete misfire.... the air that was supposed to burn the fuel goes out in the exhaust, and the O2 sensors indicate “lean” and the LTFT's rise. So it could be an injector, could be the ignition system. Problem with the “misfires” as a cause is that should cause erratic MAP readings and I didn’t notice that in the log. I'll take another look.

And while I've seen a wide variety of LTFT irregularities, your case is beyond anything I have seen before.

Which injector (cylinder #) did you replace? Was it exactly the same injector as the one you removed!

teddie300c

ive replaced the injector on cylinder 8. ive had the code for the high res signal on the opti show up twice before but it was after fixing the power steering pulley seal and one other time and that was awhile back . i figured maybe it was something just got in the way long enough to make it give the code briefly. i read that if it goes out that it will rely on the low res though in that case. my opti has a vent tube which i didnt think were on the earlier years