Bucking and hesitation are two drastically different symptoms. Bucking is most likely a cylinder miss-fire or a cylinder firing out of time. The later can be caused by a cracked, (carbon track) on the distributor cap along with a high resistance spark plug, wire, connector etc. an engine problem such as bad valve could also cause spark propagation to the wrong cylinder making for bucks, jumps, and back fires. 

Dennis   

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of B Feddish
Sent: Friday, May 1, 2015 10:50 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Still hesitating...

 

My 83.5 is still hesitating but it is more reproducible now.  The engine runs great under most circumstances, smooth acceleration and excellent gas mileage.  What happens is if I’m cruising at say a low speed in 4th, say 45mph, then take the foot off the gas momentarily then press it again that's when it does it. The van will buck violently for about 3 times then return to normal.  

Thoughts?

Thanks,

Bryan