I have a 1993 Lexus SC400 with a rough idle. However this is not the big issue that tells what the issue could possibly be.

The main issue is when I hit the throttle to accelerate the RPM gauge goes to 0 and the car bogs and has no power getting going. It doesnt buck or throw you around, just really slow and kind of blap blap idle like a small cam.

I think the rpm gauge going to 0 may indicate what the issue is. I checked the alternator...not the issue. Could it possibly be a CPS or o2 sensor issue? Where does the tach signal come from on these vehicles?

 

Check MAF sensor too. Might have a leak somewhere and not reading air coming to the intake properly.

 

sounds familiar with many other threads... Use the Search button, there are threads that may help you figure out your answers.

 

did you mess with the plugs/wires before this started happening? more detail would help you get an answer man

 

I changed my spark plugs before this same thing has happened to me.....what could that have to do with it?