Lumina won't go over 30!

My family is the original owners, all maintainence done, took out of garage from sitting for about a year, now it will not go above 30, no air leak - tested with carb cleaner on air lines, no visible external spark - tested with water spray, when you stomp on it it just bogs down, no clue what to test, timing? spark plugs and wires? the car just loads up and kinda sputters, but revvs up fine at idle, and when loaded in park runs fine also. This car is just acting WEAK like it cant even pull itself
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Any clues where to start

First clue might be what year and engine are we talking about?

What is the fuel pressure at idle?

Any trouble codes?

I've heard this story before. Very first thing I'd look for is some kind of animal nest in the airbox obstructing it, if you haven't already. I used to have a lot of customers with cars they didn't use for extended periods of time, it wasn't unusual to find a motor's airway completely hogged with bird nests, mouse nests, packed with acorns from some rodent, mud dauber nests, etc, even when parked in a garage.

For some reason, critters LOVE airboxes.

Forgot...mud daubers seem to like cat convertors too. They can plug 'em up with mud very nicely....

Forgot...mud daubers seem to like cat convertors too. They can plug 'em up with mud very nicely....
I can certainly understand critters and airboxes; and I think checking that is an excellent suggestion.

I can't tell you the number of vehicles I've encountered with critter-induced trash in the HVAC air pathway--plugged heater core or evaporator boxes.

How they'd pack the catalytic converter is a total mystery to me, though. FIRST, they'd have to get past the muffler!

My family is the original owners, all maintainence done, took out of garage from sitting for about a year, now it will not go above 30, no air leak - tested with carb cleaner on air lines, no visible external spark - tested with water spray, when you stomp on it it just bogs down, no clue what to test, timing? spark plugs and wires? the car just loads up and kinda sputters, but revvs up fine at idle, and when loaded in park runs fine also. This car is just acting WEAK like it cant even pull itself
\
Any clues where to start

any vehicle sitting for a year with untreated fuel is likely to have these problems...alcohol is not good when sitting for this long..

many a boat engine this time of year has your problem right now..

the rodents do get into vehicles..air boxes/exhaust/wire chewing all kinds of very bad stuff...