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Jim Grant's Tech Tips
'92 Dodge Dakota, Stalling Problems
Q:
My friend's ’92
Dodge Dakota pickup truck has been into the shop a number of times this
year for an intermittent stalling problem. Cold, hot, long distance, short
distance, stopped and driving, the truck has stalled under all circumstances.
The mechanic replaced the fuel pump, checked all potential problems and
is now on the second black box. The stalling has stopped, but the vehicle
idles rough and shakes both stopped and driving. The mechanic has ordered
yet another black box. He says #7 injector is a problem. First time, it
was another injector. Any thoughts?
- Joanne R.
A:
I’m not sold on
the need of another black box (computer) and I also wonder about the injector
problem. The use of a lab scope with an amp probe can pretty much prove
if the injector is a problem or if something else is going on. You should
also be aware of an internal vacuum leak that is common to Chrysler’s
V-6 and V-8 engines used in their pick-up trucks. There is a pan/cover
bolted to the bottom of the intake manifold on these engines. The gasket
that seals this cover can fail and cause an internal vacuum leak to the
engine crankcase. The failure of the gasket is common to the rear part
of the intake manifold. Depending on the level of gasket failure the engine
could just have an unsteady idle to having one or more cylinders misfiring.
Because the gasket failure is often to the rear, the cylinders affected
are often the ones in that area; back of the engine. I suggest removing
the air cleaner assembly, with the engine off, open the throttle plates
and look down into the intake. If you see oil on the bottom of the intake
then diagnosis should be directed to the gasket failure described.
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