1994 dodge spirit odd behavior

dodge
rough
engines
lights
spirit

#1

My Dodge spirit has developed a problem where when I first start the engine it will idle rough (it feels like misfires), however, after a few seconds the check engine light will come on and the car suddenly runs smooth. even though the engine then is running smoothly it can die from idling to slowly when I put it in gear. this started after my power steering belt (its a separate belt) broke and was replaced.


#2

Check under the hood for an electrical connector that has come off an engine sensor. But what you really need is to know what code(s) the computer has stored. On a Dodge, you should be able to flip the ignition on-off-on-off-on (don’t start the car), and count the flashes of the check engine light. For example a code 12 would be one flash, a short pause, two flashes. I think a code 55 means it’s done displaying codes.

It may be that a connector was knocked off when the car was worked on, and once the computer realizes that the particular sensor’s input isn’t available or doesn’t make sense, it turns on the check engine light, sets a trouble code, and ignores the missing sensor, substituting data as best it can. Of course the engine doesn’t run perfect without the missing information.

Post back the code you get.


#3

I will try it tonight when i get home, thanks.


#4

as far as i can tell its posting 12 13 13 55

here is a youtube video i took of the car displaying the code…


#5

It looks like it’s showing 13 twice to me too. Which is weird. I didn’t think it would ever display the same code twice. 12 is nothing to worry about–it means the battery was disconnected in the last 50 start-run cycles. A lot of older Chryslers seem to display this code, even when there’s nothing wrong. It may be a bug in the programming, or the computer may be overly sensitive to the voltage drop when starting. (or you may have actually disconnected the battery) Code 55 just means that it’s done displaying codes.

13 if my chart is correct, means “no change in MAP sensor value from before starting to engine running”, which would mean the sensor is bad, disconnected, or has faulty wiring to it. It could also mean the vacuum line is off the sensor or it is getting no vacuum if yours is the type that has a vacuum line connected to it instead of the type that screws into the intake manifold.

A bad or disconnected MAP (manifold absolute pressure) sensor could very well cause the type of behavior that you describe. The check engine light should be on all the time when driving with this type of failure. Pretty much, the computer is trying to use the sensor, sees no change in its reading, the engine stumbles and runs like crap, then the computer ignores the sensor and things improve. But the engine can no longer compensate properly for changing loads (like when you put it in gear), so it stalls sometimes and doesn’t have the performance it should.


#6

Could not help but notice the battery/charging indicator was a bit whacky at startup, then a bit low at charging voltage. Do you need a new battery?


#7

I happen to have a newer battery in another car… I could try it I guess. Thanks so much Oblivion, I will look into the MAP sensor and see what it might take to replace or repair it. I ordered a Haynes repair manual this afternoon, hopefully it will have the information I need.