As this occurs, debris in the valve body may be causing a valve or accumulator to stick. Under hard acceleration, the TCM - transmission control module - will command higher hydraulic pressure to ensure solid, non-slipping shifts. Has the “Service engine soon” light ever come on in relationship to the hard shifting? If not, I suspect debris in the valve body is the issue.

If I stop and shut the car off and do a normal takeoff, it is fine and won’t do it again until I do a quick takeoff. If I do a fast takeoff from a stop in my 2005 Buick LeSabre, the transmission clunks hard shifting through all gears. The specific components to test are the vapor recirculating tube, fuel filler tube, fuel tank or components related to the evap control valve or the canister itself. In brief, on certain models fitted with a “saddle”-style fuel tank, it recommends idling the engine for a minute or so to allow the fuel transfer pump to move fuel to the left side of the tank, opening space for refilling the right side.

My Alldata automotive database pulled up Chrysler service bulletin 14-001-09 REV.A dated September 2009, outlining the possible causes and repairs for this issue. The problem with difficult refueling is a different issue. Doing this at a half-dozen fill-ups or so can eventually fill the vapor separator and force liquid fuel into the canister, which is designed to capture and store fuel vapors until the engine is started and they are drawn into the induction system and burned. It’s called “fuel packing” and involves continuing to add fuel after the automatic shutoff has clicked on the nozzle. It is possible to fill the charcoal canister with fuel by regularly overfilling the tank. Is it possible to damage the charcoal filter by putting in too much gas? It sounds like the vapor venting is restricted. I have a feeling it has to do with the EVAP system. At best, I need to fill it painfully slowly. My wife’s 2005 Dodge Grand Caravan will not let us add gas to it.

2007 dodge grand caravan fuel tank