Aerostar

Does any one know what would cause a ford aerostar minivan to start "bucking" when accelerating hard or climing hills. It seems that it starts bucking when ever put under a higher load.

Thanks

Ray

Burned valve or clogged fuel filter are two cases I've seen with other vehicles.

Aerostar..Fuelpump.

Other suspects are: Plugs/wires.

Best to plug in a code reader, see if it wants to talk to you.

Throwing parts at it can become pricy.

You don't say anything about miles. If its over 100,000, and everything else is ok, I'd say oxygen sensor.

We have two of them that are bucking right now 1 is at 117k and im not sure about how many miles that other has. The one w/117k is a 93 model and the other is 96. both have 4 liter I belive.

Jamie, any way to double check if it the fuel pump with out replacing it?

Thanks

Ray

M1, if there is a Schraeder style valve on the fuel rail (usually one on a GM rail, not sure about the blue oval) you can mount a mechanical fuel pressure gage (remote...outside the hood or the like so it can be seen while driving) on the rail and see what's going on.

Maybe a tranny problem. Sounds like the torque convertor is having a valve issue when it goes into "lockup" mode. Does it only happen when you are at cruising speed and start to climb or accel? Or does it happen during slow speed as well? Certainly could be fuel supply as others have stated but I've seen this before on other ford rear wheel drives.
Mike
p.s. we have an aerostar, aka the aardvark.

M1;
From the OTC manual; Check operation of fuel pump.
Disconnect return line at fuel rail. Connect hose
from fuel rail fitting, to a calibrated container
of at least 1 quart. Connect pressure gage to fuel
diagnostic valve on fuel rail. Disconnect the
electrical connector to fuel pump located just
forward of the pump outlet. Connect auxiliary
wire harness to the connector of the fuel pump.
Energize the fuel pump for 10 seconds, with a
fully charged 12V battery, observe pressure while
energized and allow fuel to drain from hose into
container and observe the volume.
The fuel pump is operating properly if fuel
pressure reaches 35 - 45 psi, & fuel flow is a
minimum of 7.5 oz, and fuel pressure remains at
a minimum of 30 psi immediately after
de-energizing.
Mike;
On the 3.0lt Aerostars, 87-92, many a good tranies
were condemed, due to faulty Watco fuel pumps.
Best replacement were Carter fuel pumps.
Ford cost cutting?

Jamie,
good info.