1995 stratus with 2.5 automatic and 118k miles. Got a no start condition without spark one day. I changed out the distributor as this has always been the issue in the past, on my 5th distributor now. To my shock, the motor still didn't start so I went with a new crank sensor since I was getting that code (11). The motor then started but would not hold an idle without dying quickly and ran very--very-- rough at low speed, but smoothed out above 2000 revs Note that it did not run rough AT ALL BEFORE this trouble began.

Since I was still getting a crank sensor code (11), I got a replacement crank sensor thinking that the first one was marginal because it ran, but just poorly. After the second crank sensor was installed, same thing, runs rough below 2000 rpm then smooths out above that.

Put in the old distributor in case the new one was marginal. Engine started, but still runs rough at low speed. Looked over the plugs, wires, cap and saw no obvious problems except plugs in the forward bank were oil soaked so cleaned them and replaced the plug seals but got absolutely no change in engine performance.

Blocked off the EGR port on the intake to eliminate the EGR valve as a problem, also getting sick and tired of taking off the &@#%ing tube every time. Again no change in performance at all. I don't hear any massive vacuum leak when it's running as that would cause bad idle and poor low speed performance.

Was also getting an inlet air temp code (23), sensor resistance checked out as did harness voltage, but replaced the sensor anyway since it was only $20. Unfortunately, no change in engine performance. There is some minor plug oiling in the rear bank but it's not nearly as bad as the front was so I'm not expecting that to make much difference so I'll save myself the pain of working on that until I get this more major problem solved.

I'm getting an O2 sensor code (21) but I just don't think that the extreme roughness at low engine speed would be caused by that, and once again, it wasn't running rough before this all began. I'm also learning not to trust the codes-- two different sensors replaced but still getting codes and it's not running right.

Running out of ideas here, anyone have a similar experience with a possible solution? What gets me is that it ran smoothly before this, then didn't run at all so you'd think that solving the no start/no spark condition, which I did by replacing the crank sensor, would have completely fixed it.

 

Fixed my problem. Put in a third crank sensor, an OEM Mopar version this time for 4x the cost of the first two which worked, but not properly. All the other repairs needed doing anyway so I don't feel like I wasted too much effort, this just forced the issue. Lesson learned-- only use Mopar sensors! When I first started it with the Mopar crank sensor, it was missing a little bit at low rpm which had me concerned, but that smoothed out over a few miles of driving so I think the Drivetrain controller was learning to compensate (the previous sensors never smoothed out and I couldn't even get out of the driveway). Runs perfectly now.