hope some body out there can help me . i have a 90 lumina euro with a 3.1 and it will start and idle with no problem but if i let it idle for a few minutes when i tip the throttle it sounds like its starving for fuel . have replaced; timing chain,fuel pump,map sensor,tps,and crank sensor. have checked ignition, fuel pressure,have pulled injectors and flowed them. even replaced the ecm. G.M tech support doesnt have a clue . i am hoping someone out there has run into this problem and can help me out with this . any help is welcome thanks.:banghead:

With a Tech I or other data scanner connected, what happens to the injector pulse width on throttle tip-in? Ignition advance?

Check for an exhaust restriction. Drop the down pipe at the manifold studs and see if it runs better. The catalyst may have broken up.

Have you infact checked to see if maybe it is starving for fuel? Can you hook up a fuel pressure tester? I lean more towards a senser issue myself. Maybe O2 sensor, or maybe a coolant temp sensor. I've heard of the cts going bad and causing only problems when warmed up. My old 90 lumina was just the opposite, ran great untill it warmed up then it rean very very rich. Then i traded it off so i never figured out what was causing it exactly.

How is your gas mileage?? If it seems to be sucking gas it might be fuel filter. Before doing anything expensive you might think about checking the fuel filter. Also, have you had the catalytic converter inspected? On a car that old, the cat. could be really plugged up, especially if it's still the original one.