Why will my 91 Pontiac Sunbird not idle when stopped?

[William]

4 cylinder 91 Pontiac Sunbird

The car will not start unless I give it gas, and will die immediately if I take my foot off the gas. When driving, it will cruise just fine- no dying. Yet, if I come to stop at a red light or what have you, it dies unless I two-foot it. I used some fuel injector cleaner and changed the air filter. I am just baffled why the car will run fine when cruising withou my foot on the gas, but when it comes to idling while stopped- it dies!

I am not a car guy, but my gf's father is, so if anyone could give me some places to mention to him to check... it would help me look good

 

[melsg5]

when was the last time it had a full tuneup?

 

[Loonerone]

Changing the fuel filter may well solve the problem.
The Fuel pump can be suspect too.
Faulty seals of the Injectors?
Does it have an Idle solenoid or is it Carbeurated?
If carbed then possibly Floats or jets are out of adjustment.
Could also be Spark Plugs have fouled and/or spark "wires" are damaged.

 

[Loonerone]

Can also be the EGR valve being dysfunctional, Choke sticking, the PCV (pollution control valve) clogged or impeded, Vacuum lines being old and worn out and/or split, IAC (idle air control if equipped), dirty Injectors (if so equipped), Coil(s) defective.
Engines are both fun and aggravating in diagnosing defects/problems.

______________________________

 

[Loonerone]

Thank you.