silverado

iTrader: (1)

Chcked my plugs the other day and found that my passenger side bank's plugs showed a very lean condition, or signs of a vaccuum leak.

Sprayed starting fluid around base of manifold, but no change in idle. Would a bad 02 sensor result in one bank running lean? I will check things tommorrow with the auto-tap, but didnt know if this was very common, especially with drivers side plugs looking perfect.

Texas Terminator

Would a bad 02 sensor result in one bank running lean?

sure could. would probably throw a code if it was that bad though. how lean is lean? the entire bank or just one or two cylinders? scan it and get back to us.

silverado

iTrader: (1)

The entire drivers side bank (not sure if thats 1 or 2) is running lean. I tapped it and my o2 sensors looked fine, yet my injector pulse width average on bank 2 was locked at 3.99 at idle while the other bank was a bit higher and tended to vary. Would this be the injectors trying to compensate for a vacuum leak????? I'm not the best a interpreting all this info, so any input would be great. Are injector pulse width averages supposed to fluctuate or stay constant for the most part in certain conditions....ie at idle?????

Texas Terminator

that is bank one. it is not uncommon fof them to vary a bit, but locked is a different story, that doesn't seem right. does it not vary at all?

silverado

iTrader: (1)

The pusle width does change, but only in different driving conditions. At idle it would stay at 3.99, while the other one gave me constantly changing, yet similar numbers. At a steady cruise the bad bank would go to like 5.414...........again while other bank would constantly adjust and fluctuate. Its like my injector pulse width average for one bank is acting like a lazy 02 sensor. I'r really worried that I have an intake manifild vacuum leak.

Hopefully its a bad fuel pressure regulator, or a bad fuel pump/filter

Texas Terminator

it does either sound like a bad or going bad O2. you can check for vacuum leaks with some brekeclean or carb cleaner around your intake manifold. have your scanner plugged in and start logging before you do it too. i noticed you did it with starting fluid previously (wouldn't recommend that). have you checked your electrical connections? ie: O2 & injector harness. have you tried resetting the PCM? try swapping the front O2's side to side and see if the problem follows.

silverado

iTrader: (1)

I will try swapping the 02's side to side, and see what happens. Why would you not suggest starting fluid? It is what my mechanics suggested (and even gave me a free bottle of) I will also test my fuel pressure as soon as possible at start up and also change my fuel filter.

silverado

iTrader: (1)

I swapped 02's and nothing changed. Could it be that the tune I have, runs a specific injector pulse width according to which throttle position I'm in on bank two? Then adjusts the other bank based off of those readings? O2's look good, and arent lazy at all. I changed fuel filter, and truck starts a bit better, but still stumbles every now and then. (this has been happening for about a week........could a bad batch of gas cause these problems at start-up?)

Texas Terminator

starting fluid (ether) very flammable!

Texas Terminator

your tune won't make any difference in just one bank. bad gas would also affect both banks. did you come up with a fuel pressure reading? did you ever try resetting your PCM? what are your O2 readings anyway? if you are only basing your decisions on injector pulsewidth alone, that is not a good guage, especially if you have the stock injectors.