please help a girl.with a 90 lumina 3.1,starting and try pressing gas pedal then dies

I have a 1990 chevy lumina euro (2-door) and has a 1990 chevy beretta 3.1 liter (atleast thats what im told, but it does look like a lumina motor) mpfi V6, Its running very rough, the service engine light throws back a code of 34 which is a map sensor, which I have replaced, and the connector to it, and it still runs rough, and still throws back a code of 34. I had the battery disconnected for at least 20 min. When I install something new, I do the relearn process, also the service engine light does not go off, it stays on when you turn the key on untill you turn it off, I have had the spark plugs and wires replaced, also the low-coolant light stays on the same way, checked the coolant (green) level, it was good and also when I got the car, the person said there was a problem with the egr valve, I've had it replaced (also with new gasketts, which was a pretty penny) but when the egr valve is plugged in, it runs even more like crap (eratic idiling), but it would take off from complete stop, with no hesitation at all, and some reason it made the tranmission slam hard when I put it in reverse. (A friend helped me there). IF unpluged, it stalls with more hesitation and no hard slamming when put into reverse. I've also replaced the idle air conrtol sensor, throttle position sensor, map sensor, maf sensor (now ive been reading about lumina's, and everybody saids that a 90 lumina euro 3.1 dont have a maf sensor but something sits by the back top of engine by the egr valve (I wonder if the 1990 chevy beretta 3.1 mpfi has a maf sensor), it has two vacum hoses and a connector on top of it), and checked for leaks by spraying carb cleaner by the plenum and egr, and no change in idleing, also replaced the coil packs, but have not replaced the coolant temerature sensor, which I know has 2-of them, one by the thermostat and one under the egr, under the intake(now my fans turn on when they are supposed to). Also it shuts off at a red light, but will start up immediately. Alot of wierd problems so I assumed bad ecm (computer), the one that was in it has these numbers (1st line) serv.no.01227727 (2nd line) 866521 m933201830 (3rd line) 16146521 and under the bar code, 866521m933201830. Upper right hand corner of the sticker it saids ATSN. Replaced it with one I got from another mechanic and its numbers are (1st line) serv no. 01227727 (2nd line) 86bfbb m131320216 (3rd) 16190301 and under the bar code 86bfbbm131320216, upper right hand corner has the letters BFBB. I have suspicion that the computer's are wrong for the engine. when I replaced it with the one (BFBB) it ran great, idled perfect,and no more service engine light, but when it did come on, it threw back the code of 12 over and over again but nothing else, I have never heard it run so perfect, and it seemed to me that alot of the wierd problems went away. But when I put it in drive and tap on the gas pedal it dies everytime now(just dies ,no stalling or anything just dies), but i can rev the engine up when the rpm's are at 2000 or above when I let off the pedal and let it idle down and it sits right above 1000 rpm,and press the gas it dies. but i can put it in gear and dont touch the pedal and the car will move, but as soon as i touch the gas pedal it dies, but when i put the other computer that was in it, back in. it dont want to start at all, but will turn over, cant afford to stick very much more into it. Any help in this matter would be greatly apprreciated. I am very car eliterate(but I am learning alot about this, big piece of lemmon. I need a guide in the right direction. I also need a vacum diagram because i do hear a hissing sound, but looked everywhere and cant find anything, almost forgot ive changed out the 02 sensor, throttle link cable, I used to be able to drive it, but since i changed out the computer's. Im having this now pressing gas pedal problem. I got the car for free, so I cant complain, but would like to get this car up and runnin. for I am a girl with 2- kids, I really need to get this thing up and runnin. I have looked at other post and cant find anything with my problem. PLEASE HELP ME ANYBODY!!!!!!!!!!!!!!!!!!!!!
thanks for your time.

um, Jeffcoslacker will be along shortly to respond with his wisdom, but he did inform me (us on the forum) that on the 1990 luminas, the vacuum line going to the map sensor would collapse, causing it to get sucked closed, and the map to report irratic signals to the ecm. You said you replaced the map sensor, so you know where it is. Replace the vacuum line going to it also. You wont be able to tell if this is your problem if the car isnt running, because once the vacuum pressure is gone, the line expands again and looks fine. I would just take it off, and go to a hardware store and get a new line for it. Make sure it wont collaps easily. Next you hear hissing (vacuum leak)? Ok, you want to vacuum leaks whatsoever. this is probably what is causing everything. You have to find where the hissing is coming from, even if that involves tearing out every vacuum line, and replacing. There should be a vacuum diagram under your hood. Um, my next best guess on the stalling out would be fuel pressure. Are you sure that pump is pumping up enough pressure? Change your fuel filter under your drivers side door. Thats about all I got for you. more poeple will post later to give you more ideas. good luck, and report back.

um, Jeffcoslacker will be along shortly to respond with his wisdom, but he did inform me (us on the forum) that on the 1990 luminas, the vacuum line going to the map sensor would collapse, causing it to get sucked closed, and the map to report irratic signals to the ecm. You said you replaced the map sensor, so you know where it is. Replace the vacuum line going to it also. You wont be able to tell if this is your problem if the car isnt running, because once the vacuum pressure is gone, the line expands again and looks fine. I would just take it off, and go to a hardware store and get a new line for it. Make sure it wont collaps easily. Next you hear hissing (vacuum leak)? Ok, you want to vacuum leaks whatsoever. this is probably what is causing everything. You have to find where the hissing is coming from, even if that involves tearing out every vacuum line, and replacing. There should be a vacuum diagram under your hood. Um, my next best guess on the stalling out would be fuel pressure. Are you sure that pump is pumping up enough pressure? Change your fuel filter under your drivers side door. Thats about all I got for you. more poeple will post later to give you more ideas. good luck, and report back.



Thank you for even looking at the post, I will do what you say. when I have done so, I will get back. untill then thanks. It is running. I just cant accelerate. But I will look at fuel pump. How do I test the fuel pressure. I have changed the fuel filter, but I will look again and if its plugged, then will it be something in the tank itself ? right ? but also just a note, the car ran, and I could drive it to the store. but that was before I changed the ecm. But it does run and start up just fine. Would the ecm that I replaced even work for it ? I also would like to know if the engine is from a beretta, would it have to have a beretta ecm ? and one more, would the replaced ecm that I got, would it even start and make the car idle fine ? Thank you. so very much

um, I dont know about your motor. If it is in fact from a beretta, yes, get an ecm from a beretta. Preferably the same one or at least same year and model. i dont know who did the swap for you, but you have to get all the sensors and everything with the motor. did a 3.1 V6 come out? Or was it the 3.4 DOHC? If you had an ecm in it that made it accellerate, I would stick that back in. Then start narrowing down your problems from there. On the Fuel pump problem. You can buy or borrow from a mechanic, whoever, a fuel pressure guage that hooks up to the fuel rail (uh oh, is this 90 lumina throttle body injected? or does it have fuel injectors?) If the motor is from 1990 then chances are its throttle body injected, but its swapped, so it may be fuel injected. Does it have 6 injectors, or one inside like a carburator looking thing? If it has 6, the fuel pressure guage hooks up to the rail that they are all hooked to, and then you turn the key to run do not start, so the fuel pump pressurizes the rail, and you see what the pressure is at, and if it holds it. I know there is a spec, 40psi, or 60psi, somewhere around there, I think 40. it should also hold this pressure up for a while too, if it leaks off quickly, you either have a bad check valve in the pump, or a bad fuel pressure regulator. But if your car is throtle body injected, I dont know, maybe then just replace the fuel injector? That could be your problem. I dont know mush about TBI motors. sorry if i totally confused you. Its hard to diagnose over the net.

um, I dont know about your motor. If it is in fact from a beretta, yes, get an ecm from a beretta. Preferably the same one or at least same year and model. i dont know who did the swap for you, but you have to get all the sensors and everything with the motor. did a 3.1 V6 come out? Or was it the 3.4 DOHC? If you had an ecm in it that made it accellerate, I would stick that back in. Then start narrowing down your problems from there. On the Fuel pump problem. You can buy or borrow from a mechanic, whoever, a fuel pressure guage that hooks up to the fuel rail (uh oh, is this 90 lumina throttle body injected? or does it have fuel injectors?) If the motor is from 1990 then chances are its throttle body injected, but its swapped, so it may be fuel injected. Does it have 6 injectors, or one inside like a carburator looking thing? If it has 6, the fuel pressure guage hooks up to the rail that they are all hooked to, and then you turn the key to run do not start, so the fuel pump pressurizes the rail, and you see what the pressure is at, and if it holds it. I know there is a spec, 40psi, or 60psi, somewhere around there, I think 40. it should also hold this pressure up for a while too, if it leaks off quickly, you either have a bad check valve in the pump, or a bad fuel pressure regulator. But if your car is throtle body injected, I dont know, maybe then just replace the fuel injector? That could be your problem. I dont know mush about TBI motors. sorry if i totally confused you. Its hard to diagnose over the net.



I can totally agree with you on trying to diagnose this problem over the net.i will try what you said the fuel filter seems to be ok.So I will try what you have suggested.thanks a million for your input.These so called mechanics,well let me just say i ask them and all I get is I dont know could be alot of problems.where do they get those people anyway(my guess is cracker jack box).

jerk, the guys a "so called" mechanic, and thats all he can say is "could be a lot of problems"?!?!? I wouldnt go to him anymore, but maybe replace that injector. If you fuel fulter was bad before, that may be your problem now. kep us informed. good luck

Im thinking about just forgetting the whole idea, I would of liked to get this thing up and runnin, but thats not possble. Having two kids and being a single parent. Its just too costly, im so sorry. but thanks a million for helping me in anyway.GOD bless you all!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!

If you are hearing a hiss -I would follow up on the vaccum line angle,as that would make that car idle fast---i think you said a little over 100 rpm---if that's what you said -that is too high ,.The high idle is what is likely causeing the tranny to slam hard.My lumina manual is in tatters pretty much -but I i am sure that idle should be around 650 or there-abouts.
With the motor swap ,definately try and find the donor car as that car's vin number will tell you about the computer and it's e-prom.
I think you said it said mpfi on the plenum-that would tell you it's multi-port injected -not throttle body.
with the original motor -you need the original e-prom when you change ecm's-so if you swap motors you would need both the donor car's computer and e-prom.
I can't vouch for the accuracy of the information in my Haynes manual but it lists the 2.8 v6 for the 90 beretta and the 3.1 for 91 and later.However the Lumina did have the 3.1 in 90.

teh vacuum line for the MAP sensor runs from the throttle body, under the upper plenum, and then to the MAP. The vacuum line to the fuel pressure regulator branches from the same point on the the throttle body. I would say that one of the plastic vacuum lines from the throttle body is split, causing the MAP code, the lack of throttle response (due to insufficient vacuum getting to the fuel pressure regulator and MAP sensor) and the dying off idle. Inspect the lines (you'll have to remove the upper pelnum to get at the one to the MAP) and repair any that look cracked or if the rubber boots at the ends look weathered and old. Post back if this doesn't fix the problem, as you may have a bad fuel pressure regulator or fuel pump. Insufficient fuel pressure will cause the symptoms you describe.