Caravan poor idling, starting and running up to speed
 

Hi I have a 99 Grand Caravan. All of a sudden I started experiencing problems with starting the car. It turns over but takes 4-5 seconds to get going. Then the idle is very up and down for 4-5 seconds before settling. Again when the car is put into gear it can stutter and surge erratically but not always especially noticeable during warmer parts of the day. However if I stop rev the car a bit and start again I can often accelerate quite smoothly. Once I am at highway speed there is not problem at all until I stop again. If the air temp is very high I cannot get the car to start at all. I have checked the error codes on the dash and received 23 (IAT sensor). I have removed the MAP sensor and cleaned it which changed nothing, starting the car with the sensor disconnected produced exactly the same results. I currently do not have a multimeter, should I replace the MAP sensor?

Welcome to DF
If the IAT sensor Idle air temp sensor is a problem, replace it. Thats not the same as a baro/map sensor. I would also remove the throttle body and clean the AIS motor and the throttle blade.

Thanks for that will try it, on my mechanics manual it says for the 3.3L V6 the IAT sensor is intergrated into the MAP is this not the case?

The map and IAT as well as the a/c transducer and TPS share a 5 volt feed.

Replaced the map sensor no luck , I have cleaned the throttle body and checked for vacuum leaks all are fine. I cannot find the IAT sensor nor any mention of it online for this model, any ideas where I might find it? maybe its a ghost code? Thanks again

What engine size do you have?

Its a 3.3L V6. I'm beginning to think that code is irrelevant and that I might be the fuel pump I cant hear it when I turn the car on.

My 96 was doing the exact same thing! It was the EGR valve.

Bob

Following up on this I now have the car running, the problem was the fuel pump. I had hoped it was the fuel filter. The error code was completely false in this case as it is in many others. Using logic I would have gone for the fuel line first but went last due to the error code. Ignore it is my advice