93 Lumina not smooth.......

I am having a couple of issues that just started on my girlfriends 93 Lumina. I AM AT MY WITS END!!!!
When you start the car, 3.1L, it hesitates a little to start. And when it starts, it runs fine for a little while, maybe 5-10 minutes, and then either dies, or acts like it is trying to die.
Also, if I leave it in park and rev it up, whether slowly or fast, once it gets up to about 2500 rpms, it fluctuates on rpms from about 1500-2500 and I am not letting up on the gas pedal.
My girlfriend said that it was running fine and then all of the sudden died.
Check engine light is on.
REPAIRS DONE:::
I have changed spark plugs, replaced both upper dogbones, inline fuel filter, and air filter. Not sure about replacing the fuel pump quite yet. I have one that I will be pulling out of my 94 that is going to be the donor car for hers, it is a new fuel pump with only about 100 miles on it and a lifetime warranty.
Anyone have any suggestions about what else to try before yanking the motor out and replacing it, other then of course the in tank fuel pump, filter, and float?

Welcome to AF. Get a pressure gage on it and look for 37 psi, basic diagnostics here. Also get the codes.

OK, not for sure how to gauge the pressure. I am not a certified mechanic, just a decent one. And as for the codes, my code reader is for 96 and newer. Unable to get the codes, whatever it might be.

Jump terminals a and b at the aldl link under the dash, count the flashes. Get a pressure gage on the rail, only way to do this, it does sound like the pump.

ALDL??? What exactly is that? OK, maybe I am now starting to feel like a MORON. Talk to me like I have never worked on a car before I guess. I am going to ask my brother who seems to know more about vehicles than I do and see what he has to say about it. But that will be tomorrow night. Billy

Bill, the diagnostic connector under the dash near the steering column, might want to wait for the help here, less fumbling around for you. You still need a to FP gage to eliminate the obvious.

I might just go ahead and replace the fuel pump and see if that fixes the prob. If not, then I guess that we are back to square one right? Al that I know is that I have never had this much hassle with my 94. I have had it now for 5 years. I have treated that one like crap and she still runs. Barely, but she still does. The rocker arms are ticking and so are the push rods. I know that either way I will have to rebuild that one so that I can put it into hers one day. Billy

Find this connector under the dash, and short together A and B terminals with a paperclip, see what the code is.

http://www.obd-codes.com/faq/gm-aldl.jpg

Turn the key on and read the "Check Engine" light flashes as two digit numbers, i.e. five flashes, pause, then two flashes would be a 52, etc. Tell us what you get.

OK, I tried that but as of right now, it was not doing anything as for the check engine flashes. I think that it is because of the fact that there is not enough juice to start the car. It has been sitting for about a month now.

you don't need enough juice to start the vehicle. Just turn the key forward, but don't start it. (just turn the key until the guages light up) then you can read the codes. I think it will flash several times (maybe 12) before it begins spitting out your codes. P.S. If you want to get an actual code reader for the car, go to an auto parts store and ask for one, if they're nice, they'll just give you the key for free:)

Maybe I am just not doing something correctly then as for the crosswire of A and B. I put the paper clip in there and it still didn't want to flash at all. The CHECK ENGINE light stayed steadily on.:banghead:

If I remember correctly A and B are on the last two slots on the top right of the connector. If you're having trouble getting this to work, go to your favorite auto parts store and pick up a code key, like I mentioned earlier. I've never used the paper clip method, so I don't know how well it works. I'd assume it works the same as the code key, you just stick either end of the paper clip into slots A and B. Good luck

Well, my brother finally took a look at it and it ideled fine until it started warming up, then would start idling bad. Took it out for a test drive and it ran great, shifted great, even at extreme high pedal. No hesitations or anything. But stopped at the house again and it cut out. We let it set for about 10 minutes and it started up great, idled great, shut the hood with it running and within 2-3 minutes, it was idling rough again and tried to die. We immediately opened the hood and let it "cool down" while running and it smoothed back out. He believes that it is the coil pack that is bad.

Well, my brother finally took a look at it and it idled fine until it started warming up, then would start idling bad. Took it out for a test drive and it ran great, shifted great, even at extreme high pedal. No hesitations or anything. But stopped at the house again and it cut out. We let it set for about 10 minutes and it started up great, idled great, shut the hood with it running and within 2-3 minutes, it was idling rough again and tried to die. We immediately opened the hood and let it "cool down" while running and it smoothed back out. He believes that it is the coil pack that is bad.