1995 oldsmobile 98 problem please help

I have an 1995 oldsmobile 98 3.8 engine (not supercharge) when i start the car and is running the car jumps, i went to the mechanic and he changed the alternator and battery, but still the same he said is an electrical problem, but i don't know what's going on, i think is the ignition coil but i don't know where is located, please your help will be appreciated thanks in advance.

Welcome to AF, "jumps" is not going to point us in any direction, we need a better description of what is happening, why would a battery and alt. be replaced for what you describe.

where the coil is it's on top of module where your plug wires go thats your coil you can take it to auto zone and let them check it while it's on the car.

The module can be tested electronically, usually they show up ok, because unless they are hot they seldom fail. The only test on the coils is a resistance test, not done by AZ, or the usual no spark to the wire/plug and as mentioned no one knows what " jumps" is here.

i don't no why they cant test they have mine like they do the test and it might say nit'll not hitting on say number 1 or not hitting on number say 4. that tells me coil or mod.