The common thread seems to be the secondary air system. The outlet of the shut off / bypass valve for the system is broken. I just stuck a plug in the rubber line going to the head to quiet it down while I was looking at it. I'll try replacing the valve and let you know how it goes.

Thanks

Greg

From a cold/overnight start, the most glaring change is the secondary air pump which runs for 2-5 minutes and shuts off after the cooling system starts to show heat on the gauge. A leak in the hose from the pump to the exhaust would be a minor problem :)

For a car with 230K miles, you done good!!!
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My name is Klaus and I am a V ♂ lv ♂ holic.

would be nice to know how many miles you have on the old bird. when the engine is cold, it needs alot more fuel flow......things to check or have cleaned are the fuel injectors and fuel filter....your throttle body might also be sticking and need a good cleaning......also, on the 94's the air pump should come on at startup and pump air into the exhaust flow to heat up the oxygen sensor.....if you follow the tubing up to the top of the motor, you will find where it bolts on.....that hole gets jammed up with all kinds of crud and impedes the flow of air. might not cause a flutter, but should be cleaned out good. your cat could also be getting jammed up....

Maybe try cleaning the MAS wire. Your idle air control valve could be gummed up and sticking until it get warmed up. If your car has an air pump that system could also be having a problem.