on my 2000 4wd tundra, suddenly got a p307 code, misfire in cylinder #7. Replaced all plugs (over 100k on originals and they looked brand new!!), got the same code, then swapped the ignitor on #7 to #2, ran till warm and got a multiple misfire on #1, #3 and #6. Makes no sense. Can all these ignitors be bad, or is it something else? 105,000 miles, and up until now (except for 2 02 sensors) has run perfectly. This started out of the blue.
It is highly unlikely that several or all of your coil packs have simultaneously malfunctioned. Something else that effects all cylinders is the primary culprit. You just need to eliminate or confirm the possible causes.
My Haynes manual lists what low c1500 said plus checking of the vacuum lines. Have you checked all of your vacuum lines to make sure they are sealing tight at the ends and connected to the right palces?
Has the fuel filter in your truck ever been changed? If not, I would start there and pull it to see what condition it's in and to replace it regardless. I just did this on my truck and it was very easy. If you pull it, I'd check to see if it's clogged by simply blowing through it (after of course shaking out as much of the gasoline as you can.) If there is ANY significant resistance, then that might be the cause. My old filter was very difficult to blow through while the new one had almost no resistance to it at all.
A little more info would also help in diagnosing your engine.
- Before your CEL came on, could you feel that your engine was misfiring? If so, how bad was the misfire?
- Does the misfire or CEL occur while idling or when driving?
- When was the last time that your MAF and throttle body were cleaned?
- Has anything else recently been done to your engine, whether or not you think it might be related to your current problem?
That's all I got for now.