May sound off base, but check the grounds. Make sure they are all attached, clean and tight. Don’t forget the one from tranny to frame. If the grounds are wonky, the ecu won’t get a proper signal from relevant sources. HTH

Dan
Country Homes Camper, the Huckleberry Sky

> On May 25, 2018, at 1:42 PM, Dan N <dn92610@GMAIL.COM> wrote:
> 
> hi all,
> 
> my son's 1988 tintop 2.1 WBX has hiccups (vanagon syndrome) on the
> highway.. please help us to find what's wrong... he's on a trip from Oregon
> to Southern California
> 
> description of the van:
> - rebuilt 2.1 WBX about 6K miles ago
> - temp2 sensor replaced with rebuilt engine
> - new cat converter and muffler
> 
> before the trip:
> - new factory AFM (not a rebuilt) with pigtail filter
> - new spark plugs
> - new dist. cap and rotor
> - new air filter
> - new fuel filter
> - 02 sensor is one year old (about 6K miles)
> - timing checked and in order
> - throttle body checked and in order
> - vacuum leak checked, found none
> - a bottle of Heet in the gas tank (as we think water in the tank) -> no
> help
> 
> no hiccups on his way to So. Cal. (1K miles) but he got them once he's
> there...
> 
> we scratch our head and don't what else to do...
> 
> many thanks in advance if you could help.
> 
> dan