89 5.7 tbi sputters and pops at idle

[HookMeUp]

89 5.7 tbi
Starts and runs fine when cold. Once the motor is up to temp it's another story. The motor starts hard and has a rough idle( I have to mash the pedal to the floor to keep it going sputters and pops). If I slightly tap the gas pedal either under load or in neutral. It seems to flood itself out. Any ideas?
thanks

 

[SUPER64]

Have you checked the timing? Should be at 0 btdc

 

[dhcomp]

I agree, check timing. Also, make sure timing advance wire is disconnected when tming, and reconnected when you are finished.

Single brown wire on drivers side firewall, engine side, with a weather pack connector.

 

[SUPER64]

I had this issue also twice.... Once when the Fuel Pump went out and once when the Pick Up Coil went out. But the timing is a good place to start, less labor and No $$$ involved.

 

[Burbdood 74]

If it runs fine when cold and crap when hot, I'd look into the coolant temp sensor. It might be giving the ECM a wrong temp reading and it doesn't know what to do.