1998 olds cutlass jerking when shifting

You can try lucas trasmssion fix.

A humming noise in the gas tank is usually a failing fuel pump.
The pump uses liquid gasoline to keep it cool and lubricated.

Ford Idle Air Control Valve Diagnostics High Idle DTC P1506

It could be the converter is going bad or a sensor.next time you are driving it and it is jerking put your foot on the brake pedal,dont put the brakes on like you are trying to stop just push lightly on the pedal.This unlockes the converter.if it stops jerking you have a bad converter or a sensor related to it.

Is the check engine light on?

give it a visual check and if all the wires look good you should replace the sensor, consult a chilton manual for specifics

My 3.4 liter 91 Cutlass Supreme has similar problem when warm the engine misses (car jerks). But its fine at idle and without any accelerator pressure. The SERVICE ENGINE light also comes on intermittantly. I am going to test the ignition coils.

Hi,

Thanks for contacting Fixya.com
Poor acceleration is because the engine timing is wrong i.e. the ignition is early or late.
A flashing check engine light means that something serious is wrong with the vehicle and you should not be driving it. Being that the vehicle sputters and jerks under acceleration, it is assumed that you have a failure in your ignition system. Always have the car scanned when your check engine light comes on to obtain diagnosetic computer codes. Most common failure is basic maintenance items, Spark plugs and wires. Simple enough to replace, and relativly cheap. Ignition coils, ignition module, and crankshaft sensor would also cause a severe misfire. again... both pretty simple to change, but these items cost more. Start by having the vehicle checked with a scan tool first.
Aloso check distributor timing and next timing belt depending on year and how many miles on this car you may need to replace the timing belt it can be a cause too.

Let us know if you have something more to know else please accept the suggestion.
Thank You.

Check the fuel filter. Then check fuel pressure.

I would have the transaxle mount on the driver side engine compartment checked. One way to get an idea if it may be shot is to start engine, apply park brake, put transaxle in reverse and with one foot on main brake pedal and other on gas give the gas a quick tap and see if you hear a loud thump which will be the transaxle flexing the trans mount. If the rubber insulator is shot then you'll hear it.