Pulsing At Idle Options

[Jim C]

Want to see what the World thinks of this. I have a 1976 2.0 with FI. Injectors have been cleaned and checked, ECU repaired, CO checked, trigger points replaced, valves adjusted, timing set, but at idle it goes from barely running to 1000 RPM or so in a rhythmic manner. Also, when accelerating you can feel a momentary drop in power. Thoughts? (IMG:style_emoticons/default/confused24.gif)

[Literati914]

Isn't there anything you can run thru the engine that'll manifest into a visual (smoke, dye) to pin point the leak.. seafoam for example?

[JeffBowlsby]

Isn't there anything you can run thru the engine that'll manifest into a visual (smoke, dye) to pin point the leak.. seafoam for example?

Try this - engine off. Duct tape your leaf blower to the tailpipe airtight and turn it on. Check for leaks in the engine bay with a smoke pencil or a soapy solution.

The opposite method would use a shop vac at the tailpipe, and a smoke pencil to look for intake leaks.

The air plenum under the throttle body is a known common leak, at the support tubes where they penetrate through the plenum. Hard to find without removing the plenum.