Intermittant loss of acceleration on my 1991 plymouth sundance

On this i think you will find you have a pluged cadilac converter. Try taking the bolts out of the pipe going to the convert and move it out of the way so not to restrict the exhaust. You may need to wire it up to the bottom of the car so it wont drag. It is going to be loud but take it for a run if it accelerates like it should you will need to replac the converter. If it doesnt then check for a code on the TPS switch. { Throttle Posions Sencor} Good luck and hope this helps.

Disconnect the battery for a couple minutes

If you have problems, don't clear,a shop will
need the data stored to diagnose

Generally speaking, code 12 means the battery has been disconnected at some point in time.
Code 44 means the battery temp sensor circuit is out of normal range, too high or too low.

blower resistor possibly, they r cheap

I think this TSB will solve your problem even know your car is older.



NO: 18-05-96 Rev. A
GROUP: Vehicle Performance
DATE: May 24, 1996
SUBJECT: **Intermittent Rough Idle**
NOTE: This bulletin supersedes technical service bulletin 18-05-96 dated February 16, 1996 which should be removed from your files. The subject description was printed incorrectly and is marked with **ASTERISKS**
MODELS: 1991 - 1995 Acclaim/Spirit/LeBaron Sedan 1991 - 1993 Dynasty/New Yorker/New Yorker Salon 1991 - 1993 Daytona 1991 - 1995 LeBaron Coupe/LeBaron Convertible 1991 - 1994 Sundance/Shadow/Shadow Convertible 1991 - 1995 Caravan/Voyager/Town & Country NOTE: This bulletin applies to vehicles equipped with 2.2 liter and 2.5 liter engine and high pressure throttle body fuel injection.
SYMPTOM/CONDITION:
An intermittent rough idle may occur during cold engine operation, within 3 minutes after engine start up, in rainy weather and temperatures of approximately 30° to 50°F.
PARTS REQUIRED:
Quantity Part Number Part Name 1 4288298 Idle Air Control Motor (IAC) REPAIR PROCEDURE:

1. Remove A/C motor.
2. Install new IAC motor (P/N 4288298) and rubber O-ring, torque to 2 Nm (17 in. lbs).

CAUTION: The rubber o-ring must be installed with the IAC motor for proper operation.

I would also recommend doing a fuel pressure test to see if it loses fuel pressure overnight.

any time you replace the fuel pump you MUST replace the fuel filter. Sounds like it could be a couple of different things. Pick up coil if it has a distributor. bad coil pack. Replace fuel filter first .Good Luck!!!!

On the side of the engine block above the oil pan faceing the transmission.

There is a wire split under the car on driver side,but follow the wire and you should run into the prob.

buy 2 fuel filters. buy can of SEAFOAM at parts store. use 1 f filter to replace old one(you'll probably see old looking gas, with an odor).Pour SEAFOAM into tank. fill up with PREMIUM gas. after about 100 miles change out fuel filter 1 last time..add SEAFOAM every 3-5000 miles and you should be fine. the ethanol in the gas turns to goop and adds water to your fuel, and puts carbon on your valves and through out your emission and fuel system. The ethanol will be alright as long as you follow these instructions. and the SEAFOAM will keep you from having line freeze up in the cold months ahead, and will give you better gas mileage. good luck.

How old is the car? Have you tryed fuel injection cleaner? Is it well you speeding up?