Vibrating engine

my 02 quest engine vibrate while idle i did change allwire and plug and distributer cap its not help and start loosing power on the hill while going up

Shaukat, Has Any Warning Light Come On, In Particular A “Check Engine” Light ?

You may want to take this Quest to a “chain” auto parts store, like Advance or AutoZone. Many will send an employee out to the parking lot and will use a handheld code-reader to see if your van is keeping any secrets in the form of trouble codes, stored by the vehicle’s computer. Most offer this as a free service.

Write down the code(s) exactly as given to you. They should look like PO123 or P0455, etcetera. Post them here and somebody can probably advise you. The guys at the store will probably give you some information, but they are usually not mechanics, but rather parts sales people.

CSA