Volkswagen: 78 bus stall out and reluctant restart, vacuum hoses, cylinder temperature


Question
QUESTION: Hi Ron,
   having trouble with my van,was stalling when the engine was hot(open on the highway but ran great around town)when I come to a stop unless I give her gas,  I can feel a hiccup as I excelerate or when Im cruisin low throttle but then not so much when up to speed.  Now its stalling out,when the engine is cold too,but might take 3-5 minutes.  It doesn't strand me,so far, will always start after a little rest(acts flooded)..or I can pop it!  that fun in the city! Have replaced the coil, timing is nuts on, replaced some questionable ground wires.  Any thoughts?
thanks so much for this service!
Jeni

ANSWER: Hi Jeni,

Sounds like one of two things:

Either a loose or cracked vacuum hose

or

A bad #3 cylinder temperature sensor.

Either one is a pretty inexpensive fix.

First, check every hose carefully (especially the one that goes to the power brakes in the front and the rubber boot that connects to the air sensor.

If all your hoses check out perfect, than the next step is to replace the temperature sensor on cylinder head number 3.

They are 15.00 and can be obtained at:

www.mamotorworks.com

Try these two steps out.  If you have any continued problems, feel free to contact me!

Take Care,

Ron

---------- FOLLOW-UP ----------

QUESTION: Thanks for youe reply Ron.  The new temp sensor is on now and vacuum hoses have been checked(visually).  Ran cleaner thru all injectors.  Now she'll idle nicely for about 5 minutes and then cut out.  Should I take that boot right off the air sensor and replace it?  maybe electronic?
Thanks Ron.
Jeni
ANSWER: Hi Jeni,

I would take that boot off and look in between the folds of it.  The cracks tend to occur there.  

Next, check the timing.

We'll work together and keep eliminating the obvious until we find the culprit.

I don't think the air sensor is bad at this point.

Take Care,

Ron


------ Follow-up -------------

Jeni - Great follow-up.  It makes me very happy to hear that you fixed it yourself without having to spend all of the extra money!

Great work,  you did it!!!

Ron

---------- FOLLOW-UP ----------

QUESTION: Oh dang Ron,  I spoke too soon..... drove about 40 miles last night she purred like a kitten.  Pulling into the driveway. Stalled.  When I left again there was a little hiccuping and had to do the "pedal jumping" to keep her from stalling at intersections and such.  I am heading out on a trip today for four days, could something be jiggling loose? I will secure all of the hoses again..
This situation had gotten quite "severe".  now it is back to the beginning symptoms. Did replace the fuel filter and pump, just beacause I had them on hand...Its a good thing she's a volkswagen and I cant help but smile!!
Thank you for your help and encouragement!
Jeni

Answer
Hi Jeni,

It sounds like that boot is not clamped on to the throttle body good enough.  That is the most common cause of this problem.  Feel around the back of the clamp...it's probably riding up and letting in air.

I'll bet that reseating it will solve your problems.

Ron

P.S. I know what you mean about them always smiling!