van is stalling (shaking) when its changing gears on 1999 Ford Windstar

my van shakes when it is changing gears and stalls when i sit at a red light can anyone teel me what causes this

Asked by for the 1999 Ford Windstar
Do you have a Service Engine Soon Light on? It sounds like your engine is not running correctly and if the light is on, there will a code to help you figure out what it is.
no service light is not on
I don't mean a Service Light, I mean a yellow light that looks like an engine or it may say Check Engine. If your van is dying at stop signs, this light should be coming on, when it records the event that is abnormal. Have a code check done, even if it is at a parts store, I bet that there are some codes stored in your computer.
1 more answer
It might be a transmission problem. I heard this same symptom described on a radio call in show and the host/mechanic mentioned that the problem happens when the transmission is downshifting and gets caught up between two gears and that causes the vehicle to shudder. He recommended taking it in to have transmission fluid completely drained and replacing filter. If it s a manual transmission then it might be a clutch problem. Good luck.