misfires on 1 and 2?

Popping codes, general misfire, cyl 1, and cyl 2.


All I can think of is vacuum line unless cyl1 is unrelated to cyl2 issue. But issue started at same time. Bout twice a month. Happens when rockin down the highway at 75. 33's w/ 4.10s at about 3200 rpm.

But brake booster line is fed off of cyl 1.

What does evap system run off of?

4x4 actuator?

Can't seem to find a common link.

225k miles on 5vz.

Cyl 1 coil feeds cyl 4 with spark, and cyl 5 coil feeds cyl 2 with spark. Right? So not plugs, coil packs, or wires. Right? Unless its been such a minor issue on one cyl that now that its gotten worse accross two cyls its finally reporting?


Plugs were changed about 30k ago. Wires 15k. Coils 1 and 5 are orig, coil 3 is new. What are chances of two coils going out at once?

Last time I had this issue alt volt reg was shot and it was putting out 6-16v sporadically. Right now putting out a solid 14.2 +/-.2.

Help!

Also, merry chrisrmas!

 

There are many threads out there about mis-fire codes. Do a search on one (P0301, or P0302, etc). Many issues could cause it. Then narrow it down.

 

Just curious if you ever figured out the cylinder 1, cylinder 2, and random misfires? My 3.4L is doing the same thing, and having a devil of a time figuring it out.