'94 Corolla stumbles when warmed up.

I appreciate the rapid response! But looking at your answer, I'm inclined to lean more towards the ignition aspect rather than the fuel pump. I can't imagine the fuel pump only malfunctioning at slower speeds; wouldn't such a thing be more likley to manifest itself at higher RPMs? And since it runs just fine when cold, which vacuum lines would be most likely be the culprits? As for the air intake boot, do you mean before the filter? Or do you mean the cover over the air filter and plastic tube which runs between the filter and the throttle body? The latter appears to be fully intact. And by "servicing", do you mean dismantle and clean? Or replace?

Thanks,

Chris.

I talked with a neighbor, who is an instructor at the local Tech College in the diesel mechanics program, where the entire automotive/mechanical section is one big happy family, and he suggested something along the lines of the Mass Airflow System as well. I had expended about a half can of intake cleaner into the thing, but it made no difference. He also suggested I take it to a shop with the right equipment to properly diagnose the issue. :( No sense in throwing parts at the car in a hit-or-miss attempt at repairs. On the bright side, he recommended a shop about two miles away, where the owner is a former student of his. They connected their machine to it, ran it till warm, and diagnosed the Air Flow Metering system as the culprit. They then "fogged" the intake, cleaning the top end of the engine, including the intake, throttle body, and cylinder heads. $300 later it runs like a champ. My daughter is tickled pink at the newfound "power" her Corolla 1.6 has, and I'm sure she will also see gains in fuel effiiciency. He also suggested new cap, wires, plugs, etc. That's what Saturdays are made for. ;)

Again, I thank you for your input, and rest assured I will be looking to this forum again if the need arises.

Chris.