Today my car began a strange "missing" almost out of the blue .... when cruising at 55 MPH the car jerks and seems to misfire, stall.

Not sure how to isolate this problem.

I see on this site it could be accumulator, OVP, Idle Valve ..... can someone tell me where the accumulator and idle Control Valve are please?

The car ran fine yesterday. When I had a similar issue and a very rough idle, I read MikeTangas' post and put the 90* vac elbow back in and the engine was smooth as can be. This time around that vac line is in securely and this rough idle and misfire/jerking started! I was afraid I may not get home with all the shaking (idle) and jerking when driving - quite scary!

Have used FI cleaners and the like, use premium gas ..... dunno!

:-(