1994 Buick Century stalls at stop

[nuclear_assault]

I have a 1994 Buick Century with a 3.1

When the car is in park or when I'm driving, if I let up off of the gas the car stalls I'd say 1 out of every 5 times. Right before it stalls my idle drops down really low, and all of my lights dim. When I accelerate quickly the car hesitates too.

Also, my fuel pump obviously hums when I turn the car on, but then after a minute of silence it starts humming again and doesn't stop.

At first I obviously thought it was computer related. Maybe a sensor or something.....but with the lights dimming I'm not really sure.


I need to figure this problem out fast because my Trooper is acting very strange (I think it needs a new timing belt) and I have a feeling I will be carless very shortly.

[richtazz]

I'd start by checking simple things first. How long has it been since you put plug, wires, fuel filter and PCV valve on it? You can check the IAC valve in the throttle body for carbon build up, but that will normally only affect idle and just off idle performance. Lastly, you can use a DMM to check the TPS for flat spots.

[nuclear_assault]

Yeah I was going to change the fuel filter, plugs and wires, and the PCV valve anyway, seeing as I just bought the car. I'll check the IAC valve too.


....I was just wondering what would make all the lights dim before it stalls?

[taillight]

Loose or corroded battery cables.

[GM Line Rat]

Originally Posted by nuclear_assault

Right before it stalls my idle drops down really low, and all of my lights dim. When I accelerate quickly the car hesitates too. ....I was just wondering what would make all the lights dim before it stalls?

The very low idle (Engine near stalling) causes the alternator to drop below normal operating speed (Correct Idle and above)......This also causes the output voltage of the alternator to drop below normal (14Volts)......and the reason the lights are going dim. Fix the idle problem.....No more dim lights. I'd also start by removing both battery cables, Then cleaning the battery cable terminals with some baking soda and water mix...then rinse clean with water and wire brush them clean, then wire brush the battery posts too and reconnect them. Also check the connections at the alternator. you could also pull the alternator off the car and have it load tested at Autozone.....If it putting out less than a constant 13-14V at idle....It's probably the cause of your stalling.