V6 engine running on 3 cylinders

I have a 1996 Toyota Tacoma 3.4L V6. All 3 cylinders on the driver side are misfiring. I fixed a blown head gasket here a bit ago with a mechanic's help and haven't had a problem till recently. I did a tune up and replaced the spark plugs and cables but no change. My temperature gage does not work either. I replaced most of the vacuum lines but still no change. I was wondering if anyone had any ideas of what to check, where to start, and then maybe some possible fixes.

 

Start with a compression check.

 

Do you have spark on all cylinders? Fuel?

 

well i replaced all the vacuum lines and will be replacing the coil packs today after that I guess its just the fuel injectors to check. Any ideas

 

also my temperature gage does not appear to be working so I read that the engine stays in a closed loop unless the temperature gage sends the signal to the computer, any ideas?

 

Check for spark on the dead side.
If you don't have spark, backtrack the circuit until you find either a break or a bad connection.
If you've got spark, check for fuel pressure.

Good luck!

 

Coil packs are a good idea, since the 3.4 uses one coil to drive spark plugs on two cylinders.

Could also be injector wires? Basically looking for any common electrical connection among all 3 cyliners on the driver's side bank.

Any CEL codes?

I don't suppose you have an oscilloscope with current probes?

 

So the driverside cylinders are misfiring. Is it still able to run long enough for the engine to warm up? Can you explain with some detail how it idles or runs?