94 Pontiac Grand Prix SE 3.1 VSS

My car won't shift past second and the spedometer doesn't work. These are the symptoms of a bad VSS. I replaced the VSS and it ran fine for a day and now it is doing it again???? I am lost.

Look for loose wiring.

I checked the wires at the module and everything looks good. Could this be the vacuum modulator? What other wires should I check?

Just in case this has something to do with it I also have to start my car twice to get it to stay running and it is very sluggish on acceleration.

Could my ECM be bad?? How do I test the VSS module or the ECM?

First pull any trouble codes. Fix those.

The speedo signal is sent from the VSS to the ECM, then to the cluster. If there is a problem with the ECM, it would cause what you descibe.