Engine Loping

[Mike H]

I am posting this here instead of the Spridget forum since I think more people here would be familiar with my problem.
I have a '78 Midget, which I have replaced the Zenith carb with twin SU HIF4's.

This year the engine started loping at idle when warm. The idle will go up and down from 700 RPM to about 1200.

Any ideas?

Thanks

 

[jlaird]

Worn throtle shafts?

 

[tony barnhill]

When my 380SL did that, the Mercedes mechanic checked each plug wire until he found one that was bad..after he replaced it, the loping at idle stopped.