I have a 1992 Mazda 626 2.2 L with 150000 miles Manual 5 speed. Recently it had a full tune up including plugs, wires, rotor, cap, timing was adjusted and the throttle body cleaned out. This tune up was to hopefully help with the rough idle. BUT the rough idle is still there. Over all the car runs great. It has no other issues other than when at a stop the idle is rough. I have checked for vacuum leaks, the air intake snorkle for holes and no luck. ANy input would be mucho appreciated. Thanks....


Mr. Mazda Mucker

Check all 4 mounts for sagging or breakage.

it is not the mounts anyone else have an idea?

In my case, i change the throttle body & the problem is gone, goodluck.

Run a compression check. Decarbon the engine with Techron. Isolate the missing cylinder by pulling 1 plugwire off at a time while the engine is running. The one that makes the least difference in the way it runs is the offending cyl. Those were prone to idle vibration from the mounts. If it's only rough in gear then it's a mount problem.

You can also try changing the EGR valve $127.10 + gasket from Mazda. My 93 had a rough idle and was stalling very easily. The EGR lessened the rough idle but it still stalls.