I've got a 99 3.9 that giving me problems. Difficult to start this morning, started and running fine then the guages drop off. Thinking it stalled slipped it into neutral and went to restart.Bad noises since the thing was actually still running.Ran rough for a couple miles then straightened out and ran ok.Of coursecheck engine light goes off so I'm gonna assume no codes.

Have not been driving the other because it has a similar problem which started about a 8 or 9 months ago. Also no codes, cleaned injectors,replaced iac, rebuilt throttle body...

About out of vehicles that I trust.

I think you are going to need hands on diagnostics from a competant technition with the proper equipment ,because at this point I could think of a dozen things causing your runability problems .

although on the second vehicle I mentioned I've had it to several techs and nobody can come up with anything.

Mice.

Check your wiring under the hood carefully...

I will do that.