My grandaughter is having an idle problem with her 09 passion. Starts and runs normally, except that when idling it has recently started idling at about 1000 rpm, then immediately speeding up about 500 rpm, then oscillating back and forth at about a 2 or3 second rate. Isn't throwing any codes or any other abnormal behavior. I removed the air hose at the throttle body intake and couldn't see any movement of the throttle plate. Went a step further and replaaced the throttle assembly with a known-good one and it did the same thing, so I.m assuming it must be something accosiated with the fuel injection or timing. Anybody else have any kind of similar problem or ideas on the cause?