Hello! I recently purchased my first first-gen (84' gsl-se) last week and have completed most basic maintenance (oil change, diff fluid change, plugs, wires) on it aside from a fuel filter.

I'm having some difficulty diagnosing the exact cause of an idle issue I have. I haven't cleaned the throttle body yet but that is my next planned step.

When I cold start the car, it starts easily and jumps to around 2-2100 RPM and idles smoothly. After a few minutes of warming up, it bounces between 1k -1500 RPM sometimes going as low as 700 and sound like it's going to die (but never does). It finally settles down to a smooth idle at about 1200 and continues going lower (stops probably around 900). However when I drive the car around, the idle rises again to between 1k and 1200rpm while stopped. Intermittently it will drop down to about 900 at some stops. I have tried cleaning the BAC but I found no change so far. I might not have cleaned it well enough so I will also try again at that. Anything else suspicious that I should take a look at?

Thanks

 

Search on my username and "SE surging". Have at it. Oh, and... welcome aboard,