hi all, Im back!

I filled up with gas last week, and just a minute later, when merging onto the interstate, the van lost power. If I released the gas pedal, it drove normal, but of course I couldnt accelerate very swiftly. It allows me to give about 1/3 throttle and it bogs down. After a second it will take off again, but it downshifts kinda hard doing so and with 227,000 miles, I dont want to torture the transmission.

I thought I may have thrown the timing chain off as I pulled out hard from the gas station, probably at 80% throttle. I never floor it but every once in a while I come close. It did fine there, but when I slowed and got on the ramp, then started accelerating again, it started losing its power.

Having just filled up, I also suspect bad fuel, especially since we had 2" of rain the day before. I had very similar problems in a pickup truck with bad fuel. A tank drop, cleaning and refuel fixed the problem.

Also noteable, I have heard some noise lately when started in the cold that I never heard before. Its hard to describe, but it goes away once the engine is warmed up. Its not a knock, and there is always plenty of oil in it. (I keep it right at the full line at all times) I havent investigated much, which probably isnt a lot of help right now. It does seem like its coming from the 'front' of the engine. (pass side) Could easily be a pulley wearing out. (or even the AC unit again)

When I rev it in park, it does just fine. Very very responsive with a quick press of the pedal, and no backfire on idle down or anything. I can also hold it at 2500 or so RPM with no sputter or backfire. It sounds perfect.

So I figure a slipped timing chain would make it idle funky, backfire or sputter when I hold it at med-high RPMs, or not be as responsive when revved in park. Which also possibly eliminates the bad gas - though I could rev my pickup and it was fine until I tried to actually drive it.

Lastly, I though it might be the poor ol transmission finally telling me its done - but the engine speed does not increase when it loses power, as they normally do when they are dead. This tranny may be different though as I believe I read it does not have traditional bands in it. Unfortunately, I lean towards this being the issue with it running fine in park, with it revved or not. (possibly a bad solonoid or sensor within the tranny)

Ive already run out about half of the suspected bad gas, and plan to run it down to 1/4 tank before filling up with premium and putting an additive to reduce water.

So I pretty much just wanted some input on what others may suspect would be the most likely scenario.

 

Pulled some codes out, discovered the O2 sensor is most likey stuck in a rich state. Going to pull the sensor, attempt to clean it, buy a new one if its a no go. O2 sensor seems likely as its ok at idle and WOT but not at partial throttle.