I have to agree with Mark - we do go through this a few times a year. I read
these topics closely because I had some of the same issues after
reinstalling the engine in Grover.

Ran poorly after 30 seconds or so, rich running, no power, stumbling,
backfiring.

What fixed it for me was changing the Temp2 sensor. I haven't had a problem
since. Now am I saying that is the fix - nope I'm not - it's just what
worked for me.

I think the reason we go through this over and over is that no one "really"
knows what causes it - partially because it's a elusive thing and partially
because (in my opinion) there are many things that could cause it. Off the
top of my head here are the usual suspects thrown out there:

*O2
*Temp 2
*AFM
*Hall Sensor
*"Vanagon Syndrome" (also relates to AFM
*Injectors
*Grounds

These could all be right individually - or a combination of many. It could
also be that every bus that is stricken is stricken for a different
reason. Who really knows? It's a frustrating issue to those who have to go
through it. I also think it's frustrating to those trying to lend advice.

I think this is one of those issues that will continue to plague or little
community. Believe me I know next to nothing about how things really work -
but it also seems those who do know their stuff can only guess at what the
cause is.

The point to all this? Well, I'm not even sure anymore. I am just happy that
there is the knowledge of this list to try to help with this bugger of an
issue. For those of you experiencing (or who will experience) this all you
can really do is see the list above and ask the list what they would do.

Best of luck :)

--
Thanks,

Jeff
'90 Carat (Grover)
'86 (We call this one Parts)
'78 Bus (Melissa) Patty's Bus