1996 Toyota Tacoma -- Rough Idle
I have a 1996 Toyota Tacoma 2.4L 2WD. In the last couple of months, the idle has been rough when the engine is warm. Idles at approx 700 RPM. When RPM is increased, engine smooths out. No OBD error codes.
I've checked cylinder compression (ok), replaced spark plugs, cured leaks in exhaust, sprayed throttle body cleaner into the throttle body, pulled spark plug wire from each plug while engine running (all seem to make the engine idle equally rough), checked for vacuum leaks (none found), and replaced fuel filter.
Any ideas on what to do next?
Get the EGR valve vacuum tested. It may be sticking open at idle when it should be closed.