Starts good but dies after a little while

I have a 1990 Lumina 2.5 liter. I have replaced the fuel pump, fuel filter, pcv valve, pump sensor, and runned fuel treatment. The car starts and runs for about a minute and then hesitates. I'll push on the gas peddle and nothing happens. It's like it is starving for fuel or something. Whats wierd it runs good then goes south. I'm trying not to put in the shop because I like to work on my car. But I just can't figure it out. PLEASE HELP. Thanks

I had this same car with the 2.5, and that damn 2.5 was the worst engine ever. Mine seemed to be running rich all the time. In park when I'd rev it, it would almost spit and sputter like it was getting too much gas. I also had a frequent "Service Engine Soon" light that would come on. I found out from a scanner it was code 45, and it meant the car was running too rich. Those damn scanners were great at telling you what was wrong, but couldnt tell you where to start looking. I already knew it was running rich. Well anyways, back to your post. I would actually look at the O2 sensor. That might be your problem. When the O2 sensor is cold, the ECM in your car guesses the air to fuel ratio, and then when the O2 sensor warms up, it tells the ECM whats best to keep your car running. If the car runs good with no signal from the O2 sensor (when its first started and cold), but after it warms up, it dies, the O2 senser might be sending a bad signal to the ECM. I would start by just simply disconnecting the O2 sensor wire, and starting the car. It might run rough, and the "service Engin Soon" light might come on, but if it stays running, I would consider buying a new O2 sensor and replacing it. I hope this helps. I dont really know if thats your problem, but I just thought I would throw in my 2 cents worth since no one else has. Please keep me informed on how this turns out. Thanks.

Thanks for answering my question, but were is the sensor located exactly. Is it located right on the exhaust manfold on the main line. I see a line coming off of it and connecting around the altenator. This 2.5 really sucks. Know wonder they only made so many of them. Thanks

O2 sensors are screwed into the exaust near the engine. They have a wire coming out and usually a connector a foot or so away. I agree with this possibility.
My 95 APV with a 3.1 would act similar after getting hot. If you disconnect it should use a fixed set of values as if the sensor never warmed up. They have to be about 600 degrees to be active so if you have problems cold I doubt its the problem. Especially if is a single wire, not heated as yours is. $20 and you will need a special socket with opening for wire.

Yes, that is the O2 sensor you have described. Also, you do need that tool, but hey, its only 20 bux. You have already stuck so much into this car, might as well add a little more.

Thanks for the info. I'll try it and see if it works, and get back to you. Once again thanks

Hey I took your advise and disconnected the O2 sesor and it ran good while cold, but died when it got warm. I'm going to go and get a sensor tomorrow so I hope you get back to me before then. Do you think it would be good to get a Code machine from AutoZone first. THANKS

A 1990 can have the codes read at home without a reader.
Just get a paperclip or piece of wire of suitable size and place it into the 2 top right connectors on your diagnosis plug under the drivers dash.
Then turn car to on position-- DO NOT START.
It willl flash the codes on the check engine light.
The first will be 12 one flash then two flashes. This will repeat three times. You will alsso see the o2 code since you disconnected it. All this is in any car manual. I suggest you buy one if you don't already have one.

I've replaced the O2 sensor and still is dieing. The car only wants to die when you put in gear and try to go. If you never put it in gear and let it idle it stays running. If anyone has an idea please let me know. THANKS

Is this new, that it only dies when going into gear?
Maybe try to describe all current situations of when it will run when it won't. Is it easy to start will it run cold?
Does it idle rough or OK. Does it get rough when it warms up? All these things might help to know.
Temp sensors are cheap and easy to test. Might want to look there next.

quick question for everyone, did these 1990 2.5 liter luminas have mas air flow sensors? Maybe try cleaning that, I don't know, you have stumped me, if runs good when in park, and dies when its put into gear, could be a tranny problem? Try putting it in Low, 1st, or 2nd, and taking off from there, and then shifting into drive. Also another quick question. if it dies, will it start right back up, and idle in park without dying? Or does it take a while to start? When its cold, will it move? I mean, if you start it up, and put it in gear right away, will it go anywhere? I would say to sell it, those 2.5's were the worst engines ever. Good luck, keep us informed.

Also, This happened to me such a long time ago with my '90 2.5 lumina, that I almost forgot about it, but one time, I was driving, and the thing would run good untill I accellerated above 50 miles an hour. Then when I came to a stop, would idle great, but then when I went to go, I gave it gas, and it died, and it started right back up, idled good, I gave it gas, it died again, started, died, started, died. This kept going on and on, till I could accellerate slow enough to keep it from dying. Well, I drove it to the nearest mechanic and explained everything. He popped the hood, got out a wrench, and I believe pulled a fuse in a fuse box on the passenger side of the car, towards the front of it, I'm not sure anymore, he also told me that he believed it to be that "Overdrive Converter". I have never heard anything like this before, but he said he disconnected it. I got in, drove it home perfectally, no stalling, nothing, although I did notice I had no overdrive, coincodence?. When I got home, I got to my mechanic, and said, the overdrive converter is bad, he replaced it and the problem was solved. The only problem is that this happened so long ago, and I never saw the part, or where it came from, so I have no idea what one is. Or where to start looking for one, but if your problem seems anything like mine, you might want to check that fusebox for a fuse for something that sounds like an overdrive converter, and pull it, and run the car to see if anything has changed. Good luck.

Is the idle rough when it is running in park? Does the car shake alot? Theres alot of things that could cause your problem. Pulling the codes may reveal a hint or two as to what is causing it. Before you replaced the o2 sensor would the car die out just while in park? If changing the o2 sensor helped the situation any, you may need new spark plugs and/or wires. It may just need a tuneup.

Thanks for the suggestions. The car starts good while cold, but if I try to put it drive it dies. I push on the gas peddle and it does nothing. I have already diconnected my overdrive, because that was a problem. As long as I don't try to drive it. It runs perfectly fine. As soon as I back out of the driveway it stalls out and dies. I've already put a dent in the side of the car out of frustration. I have replaced the O2 sensor and still no luck. If you have any advise I'm open ears. I replaced my fuel pump about two weeks ago is there a possiblity I could have bent a fuel line puting the tank back under the car. Could that cause the problem. THANKS

I might have bigger problems. I checked my coolant and I believe there might be oil in the radiator. It's brownish and thick. I think I'm going to push this car off a cliff and watch it burn. Could this be the problem that I'm having with it dieing all the time. Thanks

Well the thick stuff is not oil. I'm thinking it could be the fuel regulator. Would do you think. THANKS

Coolant actully has a tendency of getting brown (due to rust). I wouldn't worry about that unless the engine is overheating. You said it dies when you put it in gear, therefore I would think it's an automatic, correct? You engine may just be idling too low. Try increasing the idle and see what happens.

There are plenty of sensors that could make it screw up like that. Do you have a tach in the car? If so, what speed does it idle at?

pull the ecm fuse for 10 seconds, and start the car, if it dies, restart it, and let it idle. This should reset the idle to a little higher. I might also want to say that, My 90 2.5L lumina would start great towards the end, but when put into drive, would not accelerate at all, and eventually die. This was due to a plugged Catalytic Converter. A quick test to see if yours is plugged would be to take out the air filter, and check to see if there is moisture anywhere, and if there is, Could be your Cat converter.

Yes the car is an automatic. Like I said it runs good in park but if I try to drive it it dies. I'll try the converter tomorrow. Are you saying to pull the filter out and run it for a while. Or pull it while it is not started and check it. THANKS. I'll get back to you

A quick test to see if yours is plugged would be to take out the air filter, and check to see if there is moisture anywhere, and if there is, Could be your Cat converter.

How exactly does this show that your catalytic converter is clogged?

Please, explain...

Another thought is the transmission. If the transmission is locked up, It should run fine, but force the engine to stop when put into gear.

Pull the ECM Fuse, for ten seconds, replace it, and start the car. Check the air filter. I;m not exactally sure how this works, but my trusted mechanic did it with my car, when i brought it to him and said it wouldnt accelerate, and he popped the hood, took out the air cleaner, and there was moisture, and he said, cat converter is probably plugged. He just took the car off, and car drove perfectally well, so I replaced it (500 bux, boo), and everything was good. Then I sold the car and upgraded to a 2001 Lumina, hey, its all good. Also, on the tranny note, I'm not good on tranny's, but could this be a torque converter problem?

Only thing I really know about tranny's is when they're screwed, so are you.