squirrelyammz

What's up... I have a question about strange idle problem that I just can't solve. I have a 93 del sol 5 speed manual 1.5l type S. When I get into the car and crank it in the morning the idle speed goes up to around 1500... then I drive it for a few miles until it gets to normal operating temperature. At this point when I come to a stop light the idle drops to around 200 well below the 670 mark they should be at... this goes on until I park the car and come back to it at which point the process starts all over again unless it hasn't had time to cool down where it just proceeds to almost stall out at stop lights. Now... when I cut the AC on the idle stays at it's normal 670 position but now it's starting to get cold and I don't want to be leaving the AC on in the winter so I really have to figure this one out.

I've replaced the IAC valve which was faulty initially and put the idle to the 670 afterwards it didn't work.... I've replaced the fuel pump, all the spark plugs, the air filter, the spark plug wires, the distributor rotor and cap, and ran 97 octane fuel through it with Lucas fuel injector cleaner for the past month. I've also had the valve clearance adjusted and the timing belt replaced recently.. basically a full tune up. I was thinking a vaccum leak but you can normally hear them and there are no vaccum hisses coming from the engine bay.... oh and I also replaced the PCV valve..... nothing seems to help me out... I am hoping someone in the forum can. Any suggestions would be greatly appreciated.

Thanks.