Hi, again, people.
 
This question concerns a '77 bus, and its fuel injection system.
 
I'm having the intermittent problem with the following symptoms:
At idle (sometimes), the engine will just quit.  It may sputter
briefly before stopping, then will not be able to immediately
restart.  After a minute or two (which seems like an eternity
if traffic starts to back up), the bus will restart and run OK
until the next episode.  The same problem happens while driving.
 
I recently replaced the fuel filter, points and plugs.  I've
cleaned off all the electrical connections in the engine compartment
and on the starter & solenoid, and checked that they were indeed
connecting.  I've checked that the vacuum hoses were all connected,
and that the ends were not split and frayed.
 
The double relay seems to be getting current as indicated by the
Bently manual. I checked the cylinder head temperature sended, and
it seemed to give the correct resistance.  However, I'm unsure whether
I should measure the current from the harness to ground, or some other
way. I've also adjusted the timing (note: when I rebuilt the engine
I installed hydraulic lifters and pushrods, so they shouldn't need
adjusting).  I found a loose connector to terminal 9 on the intake
air sensor, but that didn't solve the problem, though the engine
died when I disconnected that wire.  I saw that voltage to the
injectors increased with engine rpm.
 
In the near future I will probe around in the air intake sensor,
to make sure the flap is not hanging up, and recheck the two
temperature senders.  I will also construct a fuel pressure guage
and replace all the vacuum hoses and (as soon as I locate bosch)
install new spark plug wires.
 
Where else should I look, and where should I pay especially close
attention?
 
Would faulty temperature senders cause the engine to lose power,
rpms, and then quit?  What else would cause the engine to completely
stall, but run OK the rest of the time?  I think the idle is a little
rough, but not as bad as I've heard elsewhere.  Boy, do these
intermittent problems get to me. Still, I've learned a lot about how
this FI works by experimenting with my VOM, and of course reading
Bentley and Muir.  It would be fun if it weren't my only car.
 
One other point of information:  the problem happened three times
Friday night, when the temperature was in the 90s.  It ran fine
on Monday when the temperature was in the 60s.  Of course, this
is a spurious relationship, because this problem happened earlier
this spring in cooler weather.
 
Finally, does anybody know of a good parts or repair shop in Chicagoland?
There's a place in Addison named Spencer's Home for Battered Bugs which
sounds promising.  Otherwise, I'll get in touch with Courtesy Auto in
Madison, Wis. (which I highly recommend).
 
 
Thanks in advance!
 
joel danke
 
P.S.  I'm on digest, so I'll be able to respond more effectively
if CC'd.  Thanks again!
 
jdanke@macc.wisc.edu