loss of power

hi can anyone shead any light on my 2001 ulysse, losing power. the k light lights most of the time.the fault seams to start the first time you take your foot off the throttle. if you turn the engine off for a few seconds and restart sometimes you are lucky and have full power some times you dont, also when i turn the car off the engine carrys on running for a couple of seconds any ideas, oh its a 19 jtd.

Hi mate, and WELCOME TO THE FORUM!

As the EOBD light is illuminated, there will be fault code/s stored in the ECU. best bet is to have these read. Should pinpoint exactly whats causing the problem. I would suggest it is something to do with the butterfly valve on the inlet manifold. This shuts off the air supply to the engine when the ignition is turned off, thus stopping the engine from running. Sometimes these can stick or break, causing lack of power or non running. The fact that the engine is running on after being switched off, would lead me to belive that either the valve is sticking, or there is a leak in the vacuume system that operates the valve meaning it is not opening/closing properly. Worth having a fiddle to check its moving freely.

Hope that helps,
Alan