Random Idle Surging w/cel

[kbaszak]

I've got an 87 325is that will run fine for days and then randomly start to idle surge at a stop light with the cel on. If I shut off the car and turn in back on, it runs fine. I have 153 dme so I can't check the codes but does anyone have any idea as to what might be causing this?

[dnguyen1963]

random vacuum leaks. Check the elbows going into the throttle body.

[jlevie]

random vacuum leaks. Check the elbows going into the throttle body.

Better yet, have a smoke test run and find all the leaks.

[audiquattrot]

had a similar issue at stop lights. ended up being the hose that connects from the valve cover to the intake manifold.