It is your exhaust leak and system. 

sent from my iPhone 
Joel

On Aug 10, 2011, at 8:30 AM, T Collins <tonycollin@GMAIL.COM> wrote:

> Hi Daniel,
> 
> I like to share with you what my 85 did. I would cruse at high way speeds
> 70mph here in Michigan. The van would sort of hiccup, tremble, hesitate and
> something just did not feel right. It was like the van wanted to quite at
> mid flight.
> 
> It was just enough of a feeling that lasted a split second to make me
> worried that this was the dreaded vanagon syndrome. I also had a exhaust
> leak at the time. So I was certain that the leak pre O2 sensor had something
> to do with this.
> 
> I fixed what I knew was certainly wrong. New exhaust, O2 and temp2 sensors,
> replaced fuel filter the (box one) and added the can after the fuel pump.
> Some of this helped, but at the end the van got so bad that I could start it
> and it would idle, but as soon as any load was applied the van would bog
> down and die.
> 
> I also messed with the AFM getting a know working one to swap in and test
> and still noting!!!
> 
> long story short and with me absolutely frustrated i dropped it off at the
> local VW independent shop. The old salty-dog mechanic there blew some air
> into the (slow, steady stream) into the outlet (fuel pump side) of the tank,
> until he could hear bubbles. Then plugged everything ups and the van has
> been running great for 2 years now.
> 
> There was accumulated crud in the gas tank blocking the delivery of fuel to
> the pump starving it. These happened slowly at first the hesitation at
> highway speeds, and then later magnified by the van sitting while I tackled
> the exhaust.
> 
> The key I should have been listening for was that the pump was being
> extraordinarily load and working overtime to get any fuel. I'm amazed in
> retrospect that I did not burn it out.
> 
> The fuel delivery can be a simple thing to assess before moving to the spark
> and air area of things. If your pump is load it maybe worth checking, and
> seeing if some compress air with a low or partially drained fuel tank makes
> a difference to your situation.
> 
> The caveat is that there is no way of knowing how much crap build up we have
> in our old tanks until we take then out and inspect. Not a job I want to do
> on the side of the road.
> 
> I hope this helps! I keep recalling to try and see the issues from the
> simplest to the largest , before just tossing money at it and replacing
> parts that are potentially good.
> 
> Good luck,
> Tony
> 
> On Mon, Aug 8, 2011 at 6:27 PM, Daniel Rotblatt <d.rotblatt@verizon.net>wrote:
> 
>> I'm leaving Sante Fe on the return leg to L.A. The van is hesitating
>> while on freeway.  Momentary hesitations - randomly every few seconds.
>> 
>> Otherwise running great.  When I had it tuned up it had trouble
>> starting and mechanic put in new fuel pump relay.
>> 
>> Thoughts?  Just pit in gas also...was running fine before that.  Bad
>> gas?  Fuel pump?
>> 
>> Dan
>> '85 Vanagon
>> 
>> Sent from my iPhone
>> 
> 
> 
> 
> --
> 82 Scirocco "Rodolfo"
> 85 Vanagon "El Guapo"
> http://groups.google.com/group/wash-co-vws2<http://groups.google.com/group/wash-co-vws2?lnk=gcimh>
> (new)