Engine is sometimes trying to "cut out". Doesn't cause check engine light to come on on 1997 Lexus ES300

Dealership replaced the VSV which did absolutely NO good. Feels like it wants to quit at times while driving. Doesn't do it all the time -- just sometimes but can be very bad. Mechanics are stumped. Had suggestion from friend that it may be the Ilde Air Control Valve. Any suggestions? Dealer is bringing in a "master mechanic" - don't want to pay "master" bucks. thx

Asked by for the 1997 Lexus ES300
1 answer 2 comments
talk to the service manager at the dealer. ask why you should pay for a repair that did not fix the car. you paid them; the car needs to be fixed right. anything else, like
the IAC is just a guess.
Thanks. We are asking for the money back, but they are bringing in the master mechanic tomorrow. Any suggestions on what to check besides the IAC?
under normal circumstances, the dealer has the best of the best
because all their training is for Lexus only. they should want
to resolve this very strongly, after all, if they can't fix
this, who can? otherwise, a full refund should be expected. would advise against giving them any suggestions at this point.
let them try to do their job.