Hi. I have a 4 cylinder manual topaz that when the engine is running will
have and intermittent drop of RPM's, weather in neutral or driving it will
suddenly drop 500-1000 RPM's. This occurs every 20-30 seconds while driving
and every 10-15 while idling. I replaced the fuel filter but no improvement.
I don't know what to try next. Any idea's would be great.