[malibumlk]

Hitec,
See if this gives you a clue as to lean or rich;
But first....it's had an air filter change as part of the troubleshooting with no efect at all......and the old one was really dirty, possibly 70k miles on it.

Next: It does has a rough stumble at idle on start up, more pronounced at cold start. The idle smooths out in about 2 seconds or less to a normal mode. While looking for vacc. leaks, I had the air filter housing out, MAF in place with engine at idle. I noticed that if the MAF housing fell out of the boot while I was reaching down in there looking for vacc. leaks, after a few seconds, the idle would get rough just like at start up. I would think this to be a lean condition in that the MAF seeing no air flow would begin to meter fuel way back......and I got a similar studder idle.

On the other hand, I'd think things would naturally be pretty rich on a cold start......vacc leak or not......so studder idle associated with rich condition.

Last - plugs look normal.

Does that help at all?

Is any of my thinking and observations in my prior post off base??

Thanks again,
MK