Because the catalytic converter('s) are stopped up
That's one possibility, but you should also check over obvious things like clean filters, good fuel delivery, no vacuum leaks, etc. Might want to check the ignition timing while you're at it.
The engine coolant temp sensor can do that. If you have a check engine light on, have the codes read.
check cat converter if it has 75000 miles or more
does it start without the choke? if it does you are probably flooding the engine with the choke readjust it
sounds like you need a new accelarator pump in your carburettor
Your engine has worn piston rings. Get it fixed asap because the oil is no good and will seize the motor. it can also come from flooding carb especially on new engine
If your 1990 Lumina has gas in the oil pan, then there could be a stuck injector flooding the engine. There can also be a blown head gasket. Driving the vehicle can destroy the engine.
if throttle body is flooding engine how can i fix .4.3engine on 88 Chevy blazer motor was running great on morning wont start. new gas tank plugs wires ,sending unit.and throttle body.motor turns over wants to start ,there is fire to plugs and fuel to throttle body,also new rotor button
A faulty engine coolant temp sensor can cause that.
Bad engine coolant sensor. Bad fuel injector. Plugged air filter.
A plugged up fuel filter.
I am searching for 409 chevy engine
If it has a v-lsd it will.