|
Jim Grant's Tech Tips
88 Dodge Caravan: Once a Week Stall
Q: I have a 1988 Dodge Caravan with a stalling problem that a number
of garages can't diagnose. It stalls going about 20-25 MPH usually when
I turn a corner and let my foot off the accelerator or if I'm going up
a driveway that's on a hill.
It also stalls
going into reverse, but every time it stalls, my foot is lightly on the
accelerator and I can start it right up again. I've replaced the MAP sensor,
TPS sensor, plug wires, power module, had an injector cleaning, and carbon
treatment. Also the car usually only stalls once a week. I would like
to keep the car till the fall, so I hope you have a suggestion.
A: Only
stalls once a week? Why that's simple, just don't drive it on that day.
A once a week stalling problem can be a real bear to diagnose and correct.
You did provide
a piece of information that could be helpful. The stalling condition occurs
when your foot is lightly on the gas pedal. There are two items that would
be worth checking: First, are the throttle plates clean and adjusted correctly?
There is a problem with deposits building up on the throttle plates on
vehicles of your type. This will cause a stalling condition which creates
the next problem: Second, incorrectly adjusting idle speed to cure a stalling
condition will reposition the throttle plates. This can cause certain
emissions controls to be active prematurely, resulting in a man made stalling
condition. Correct throttle plate positioning is critical to today's computerized
engines. A qualified technician must have specialized tools to correctly
adjust and set throttle position.
If the throttle
plates are not the problem then this service bulletin is worth checking
into. The ALLDATA Information System shows a bulletin #18-13-91 that addresses
the condition you describe. The fix requires a reprogrammed computer and
modification to emissions controls that are active under very light throttle
or light acceleration. The bulletin provides the necessary part number
and repair procedure.
|
