'91 300E with 120k vehicle hesitates when starting in traffic. Also black smoke from exhaust when accelerating and poor gas mileage. Just changed plugs, wires, rotor, cap still no improvement. Any suggestions?

Running rich. What did the plugs look like?? Could be a number of things.

__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.

Plugs were black. Is it possible that an adjustment needs to be made or could a sensor have gone bad.

Could be a number of things. Mixture control. Loss of temp input to CIS, EHA, etc. Get a good diagnosis from a tech you trust.

__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.

sounds like your air/fuel mixture needs to be adjusted, there is a special tool that goes in the hole on top of you air filter housing to adjust that.

Have you checked the overvotage protection relay fuse behind the battery?

Good luck,