I have an idle problem with my 2.6l 4ZE1 1995 in that it idles a bit rough. I have checked plugs, valve clearances, timing, vacuum hoses, replaced fuel filter, air filter, cleaned the MAFS, cleaned the Throttle Body and run a can of injector cleaner through (Toyota Stuff, which I am told is the best), all with very little or no change. Idle is steady at 900 rpm though it does vary slightly. I haven't checked compression, fuel pressure or the injectors, so could be one or more of those, she doesn't blow any smoke and seems fuel efficient (400km on a tank), she runs very nicely at all other rpms. Fast Idle works at cold start up and when Air con is switched on, so I believe those parts are working ok, though they do seem to leak a little vacuum when checked but it is very minor and a finger over the vacuum points makes no difference. I have not been able to locate the ERG valve and don't appear to have an exhaust gas take off on the exhaust or exhaust manifold that I can see, so not sure if its been removed or if there ever was one. Its not on the firewall end of the manifold which is where I think its supposed to be.
Any other thoughts? Should I pull the injectors and clean them in an ultrasonic bath with new filters and seals or am I looking for something else?
Cheers