since this monday (thursday now), my 99 SE V6 manual tranny, has not been running right. it has ~81k miles on it. It has serious jerky hesitation when accelerating, especially at lower RPM's (1000-3000) but continues up the RPM band. It is so jerky that when trying to change the radio station on my radio, it causes me to hit about three other buttons at the same time. At idle, every 10 seconds or so, there is a bump from the engine. The hesitation and jerkyness is MOST noticable at ~40MPH in 5th gear which is somewhere in the neighborhood of 2000RPM. When cruising down the freeway in 5th gear (68MPH), ~3000RPM, it is not even noticable. The CEL was blinking (for about 40 seconds at 2 second intervals) at one point then went away. Then the next time driving, it started blinking again then went away after about 40 seconds again. After a few other driving sessions, the CEL came on (not blinking). I disconnected the battery to reset the computer, hoping the reset may have a good effect, but it didn't change anything. Now, it is thursday, it is still running badly and the CEL has NOT come on again.
At first, I thought it was bad gas (87 octane from Wal-Mart) that i had just gotten. But after 1/2 a tank, i filled the rest up with 93 octane from 76. Problem was still there. Then i added some fuel injector cleaner just to make sure. Now i've used a little more than a 1/4 of a tank and it is still there. Then i thought it might be a bad spark plug. So i took them out one by one, and checked them. They looked ok, but i did notice black deposits on all the plugs, which i didn't notice on the old plugs when i changed them about 10,000 miles ago (at around 70k). Any ideas or suggestions?
