3100 running rough

[himsa669]

i have a 1999 buick century that started runnin oddly this morning. i rolled out of my drive way and it killed itself. battery was still good so started back up and would hardly hold idle. after a few tries it started to run and it stopped on my way to work. the car turns over and when it does idle it is rough and kind of pulses as in the rpm raises and then drops. under throttle it does the same pulsing. the ses light is on but i can"t get to a code reader. does this sound familiar to any one? any help is much appreciated!

[himsa669]

when i turn the key to the on position i can't hear the fuel pump prime. does any one have this car or know a way to test the fuel pump?

[himsa669]

ok so scratch that last one jumped it from a battery and now she idles. but when i put it in reverse the car died. i also turned my left blinker on and that killed the car as well. A bad relay maybe? i"m pretty stumped any input would be greatly appreciated.

[Azrael]

Without a code reader this sounds like it'll be difficult to pin down. Do you have a volt-meter? Check voltage when the car's running and you can at least rule out a bad alternator + discharged battery. A fully charged battery should read 12.6v with the car off. ~14.4v while running.

[himsa669]

got the alt tested already ses light went off. battery was dead 13 cca. i could get it to idle but as soon as i put it in gear it would die. is this because of the bad battery? or do i have other problems? thanks for the input

[2.8/3400 1985 Camaro]

Checking the fuel pump is easy, just disconnect the fuel feed line in the engine bay(easier) or at the fuel filter(if you haven't done maintenance on the car regularly then you should probably change it anyway) turn the ignition and see if it starts shooting fuel out, pretty straight forward, should be a consistent stream, if its not or seems weak, then you might not be getting enough pressure..... other than that you might check the air filter, could also check your fuses, also when you check the air filter, disconnect the hose from the air intake box and throttle body, and look and see if there's a black gunk built up around the throttle plate, if so clean it out with carb and choke cleaner, basically it can get carbon deposits, and when the throttle plate is barely open (ie. while idling or in gear without pressing the pedal) the carbon deposits can block it and choke the engine, I had a car that started stalling on me with increasing frequency for this very reason. If you don't know your way around an engine PM me and I can explain how to check the minor things, for the more major stuff you'll need to get someone else to check it if you don't know much about engines.
And you would be surprised what a little maintenance can do, so if you haven't had any done recently consider it, if it hasn't been done in a long enough time it could easily be the source of your problems, and conversely having it done may very well solve them.

So things to check if its not battery or alternator:
-fuses
-fuel filter and fuel pump
-air filter
-carbon deposits on throttle body

Those are the little things, if you're lucky its one of those, if not it might be something more major like the following:
-bad spark plugs
-clogged fuel injectors
-ignition timing
-valvetrain timing

[Azrael]

It could also be the idle air control valve on the throttlebody. It could be stuck almost closed or just be really really sluggish.

[himsa669]

Thanks for the responses! i have checked every fuse and alt. the battery came up bad but i did turn it over quite a bit while trying to figure this out. i jumped it from another battery and it idles and responds to the throttle normallly but as soon as i put it in gear the engine rpms fall considerably until the motor dies. also if i put on the left blinker it dies as well. is this attributed to the bad battery? i know my way around an engine very well and if the new batt doesn't solve the problem i'll pm ya. thanks again

[Azrael]

Does it stall in "D" too or just "R"? You can also try pulling the fuses/circuit breakers for the exterior lighting system to rule out a short in the harness somewhere. It might not take much if the battery's dead and the alt is spending most of it's output trying to charge it.

[himsa669]

ok so got a new batt and takes a couple tries to start but once it starts it will accept throttle and it stalls in any gear. once it stalls it is really hard to start. probably should have said this from the beggining (not sure if it caused it) the car started dying after i hooked up a sub and amp. i unplugged them as soon as the car started acting weird and haven't plugged them in since. ok so it dies when the left blinker is on and the steering wheel turns. Short maybe?

[bszopi]

I would check wherever you ran the wire for the amp. Good chance that wire has a nick that is causing you issues.

[himsa669]

when i try and start the car it kind of lurches forward when it starts as well. sorry for so many posts i have to take this to work tomorrow. all wires are disconected and i kept stock head unit.

[primesuspect]

I doubt if this is the problem, but its worth a quick peek: The alternate positive battery boost terminal located on your drivers side inner fender holds all kiinds of fuses and relays. I had an isseu with a 96 regal that acted as if the car was haunted. all kinds of weird issues. It was all because the terminal has a plastic housing that easily cracks with temp change or roughly connecting cables to it. Check to see if it is cracked as this may cause some messed up symptoms. Like i said this is likely not your problem but its easy to spot and worth the check.

Cheers

[not_a_gtp]

Although it sounds like more of an electrical issue, Has the ICM ever been replaced? how many miles on the car/engine?

[bszopi]

If you want to through in wierd situations... On an Alero I owned, I was having starting issues (twice). The first time, it ended up being a loose connection INSIDE the fuse block. The second time was a faulty ignition switch. Electrical issues are a PITA to try to trace down.