Jim Grant's Tech Tips
Grand Caravan, Random Spitting & Sputtering
Q: I have a ‘90 Dodge Grand Caravan, with
a 3.3L V6 in it with approximately150k. We have changed the fuel pump
and fuel filter and are still having problems...Sometimes it will start
and run fine and sometimes it will spit, sputter, cut out and backfire,
especially when I'm going up a hill....Can you please help me with this
I would suggest rechecking the fuel pressure. The reason for this? We’ve
been seeing corrosion problems in the wiring to the fuel pump. The corrosion,
which seem to be sensitive to temperature and bumps, can cause a reduction
in electrical power to the fuel pump. This translates into reduced fuel
pressure. The best way to approach this problem, if it cannot be duplicated
in the shop bay, is to drive the vehicle with a fuel pressure gauge connected
to allow you to monitor the fuel pressure when the problem is occurring.
If fuel pressure doesn’t drop, like the engine does when it’s having its
throwing its fit, then there are other problems.