ok here it goes, I have a 1991 lumina 3.1V6 and my car surges when warm. Its weird cause it wont do it until it gets warm and you could be driving down the highway and out of nowhere with the cruise on it will surge out of nowhere, so i replaced the throttle position sensor and then the light came back on so i replaced the wiring for the throttle positon sensor and that code never came back up, wellllll then i got another code IAC so i replaced it and now im getting a MAP sensor and O2 sensor, doesnt make sense cause they have been replaced, now what i have done to the car. New starter, cleaned the EGR valve, replaced air compressor, exhaust (no cat just straight pipe) throttle position sensor, IAC, radiator, water pump, thermostat, now i know lots of what has been done doesnt interfer with what its doin but i thought i just state it anyways, oh when when i did replace the IAC yesterday i let the car warm up for about 25 mins then i took it for a spin and it ran fine down the street but coming back up i would hit the gas and it would die and it did that 10 times so i had to just coast back home without touching the gas... PLEEEEEEEEEEEEEASE HELP i need to get this figured out before i leave to Basic

oh and the car has 210K

Lots of parts but no real diagnosis here, check the fuel pressure at the rail when this occurs, need 37 psi., also what are/were the codes?

fuel pressure is just fine, i forgot to mention i replaced fuel pump also, codes that came up were 34 and 44, previously it was 22 and 35 but now they dont come up

lotsa low voltage warnings. have you checked your wiring for shorts? just an idea. i just went thru all those symptoms. stalling at red lights, loss of power, and surging. seemed to come and go. i spent a small fortune getting rid of the problem. new iac, tps, o2, map, flushed tranny, seafoamed vac lines, the list goes on and on. im finally running right. but at a big cost...

If you had included the info in your last post on the original post, we both could have shortened this process, the 34 map code points to weak vacuum at the map sensor or a bad map, 44 goes along with the 34. Tackle the map issue first.

map sensor goes for about $100 and is virtually a pop off / pop on process. it made a world of difference on mine. pretty much doubled my gas mileage and cured that lil smoking/surge issue!!!

thanks for the information i will try a new map and check the vacuum lines out and hopefully that will end my headache:runaround:

If the car has milage over 175,000 with the origional fuel injectors I am sure this is the problem. I have a lumina with 333,333 and every 175,000 I have to replace all the fuel injectors. Then all those codes will disapear and the car will run great for another 175,000. You can purchase a set of six fuel injectors from Summit Racing out of Talmage, OH. The brand is Accell. Make sure you by the stock version. If you buy injectors at the autoparts store they will cost you $50 each for an off brand or rebuilt or $100 for Borg Warner. I would check the fuel pressure and other obvious stuff, like using a good brand fuel injector cleaner but if you have the orgional injectors and the care has around 175,000 it should be the fuel injectors. Been there done that replaced the same stuff you did and have the T-Shirt or two!

all of this started when i had the same probs that he did. one thing led to another. everything listed below was what i did in the past year:
dog bone strut
IAC
All Vacuum Hoses
Front left engine mount
plugs & wires
radiator
altenator
injection service
fuel filter
pcv valve
serp belt
cat converter
battery
rebuilt a/c
tps
air filter conversion
fuel pump
radiator hoses
steering column
starter & solenoid
o2 sensor
map sensor
windshield
back window re-seal
tires
alignment
door handle
ceramic brakes
rotors
dash board re-covered
had block, fuel, and vacuum pressure tested
diagnostics done
all wiring checked
and soon: injectors and timing
forgot to mention that i had the tcc sticking problem as well. i drained a pint of tranny fluid then replaced it with seafoam transtune. ran a few days then flushed the tranny. prob solved. also put some transtune in the power steering resevoir. had a slight whine that went away afterward. and yes regular oil changes. 10w30 fully synthetic.

cosmetics i need done:
bra
tint windows

THATS IT!!!
I put a little over 5k into it so far. its a brand new car with 208k on it...

If the car has milage over 175,000 with the origional fuel injectors I am sure this is the problem. I have a lumina with 333,333 and every 175,000 I have to replace all the fuel injectors. Then all those codes will disapear and the car will run great for another 175,000. You can purchase a set of six fuel injectors from Summit Racing out of Talmage, OH. The brand is Accell. Make sure you by the stock version. If you buy injectors at the autoparts store they will cost you $50 each for an off brand or rebuilt or $100 for Borg Warner. I would check the fuel pressure and other obvious stuff, like using a good brand fuel injector cleaner but if you have the orgional injectors and the care has around 175,000 it should be the fuel injectors. Been there done that replaced the same stuff you did and have the T-Shirt or two!
How does the map sensor code equate to bad injectors here, I believe addt'l diagnosis is required before this kind of repair/investment is tackled.

My TCC was sticking last year and I just unplugged it and its been unplugged for about a year now, but anyways I got bored yesterday and since I'm always curious to learn more about car I took the intake manifold off and pretty much disconnected all vacuum lines, took the fuel rail off, the injectors had this nasty build up at the end of them so i clean that off some of the vacuum lines had little cracks in them and some had bad cracks at the end, i completely took the throttle body off and there was alot of carbon build up so I cleaned that to the point where it looks brand new the thing that the egr vavle mounts to, the tube that runs down to the exhaust had a crack in it, the more i dig down into my car the more things i find wrong. I know when I bought this car in Feb 2007 it had been abused mechanically and the oil was the darkest black I have ever seen but the body was in awesome shape and thats all i cared about. I have replaces
A/C Compressor
Fuel Pump
Fuel Filter
Radiator
Water Pump
Radiator hoses
Throttle Position Sensor
IAC Valve
Exhaust with no cat
Starter
Crank Position Sensor
Upper and lower intake gaskets
I'm glad I know how to do all those things on cars cause otherwise I would of made a mechanic rich

max, we were just going thru steps that eventually led to the injectors. new o2, map, cleaned the egr, etc... i had a couple mechanics agree that it wasnt the injectors that was causing that issue. step by step we ruled out certain things. hopefully i have it fixed now. gotta give it a couple days to see. the issue is black smoke and surging only once in a while. loss of power and the sound was like gurgling. one mechanic said it was a fuel related issue. which led to the injectors. another mechanic said change this, change that. so I did. I can afford it. im one step further today than i was yesterday. as i said in another thread, its a brand new car with 208k miles on it. ill replace just about anything to keep it running. eventually i'll replace the right thing. lol

ok i got another question, i took off the lower intake and i was looking it at the valves and the valves have ALOT of build up and nasty black crap on them and i was wondering what could i do to clean them, like any additives or anything like that

deep creep will clean em just fine. its a seafoam product and the most powerfull in my opinion. i used it in my upper intake and egr hose. just allow it enough time to do its thing. dont forget to check the condition of all your gaskets as well...

i was just about to ask that, i took off all the rocker arms today to take the lower gasket out even though i didnt need to take all of them off only 6 but i was thinking the car has 210K miles on it and the head gaskets have never been replaced do you think i should go ahead and take the heads off and save time last on or just wait, i wont be driving the car from sept-march cause ill be in basic training and ait but i will be driving it again when i get back, just want some opinions

ok now im getting a little annoyed with this car, i tore everything down to the heads, cleaned the push rods cause they had alot of build up on them put all new gaskets in new TPS and tps wiring, new iac, new coolant sensor and coolant sensor wiring, map sensor and a new fuel injector fuel regulator and the car starts up fine and idles perfect and runs perfect but once it gets hot the car simply runs like SHIT, i would pull out of the drive way and give it gas and get NOTHING and if i hold it there then it will take off and then cut back out and then go again and then sometimes die, i took the igniton coils off and got them test and they tested good, same with the ignition module, it has new plugs and new wires, vaccum lines have been replaced, injectors have been clean i have NO IDEA what else could be going wrong im bout to throw this car away

get it scanned. see if your ecm is working properly...
heres what happened to me, surging and black smoke when I throttled pretty hard. mech said it was fuel related cuz of the black smoke. sooooo, new fuel pump, fuel filter, map sensor and o2 sensor. the problem remained, if not even worse. my mechanic called in a specialist who had a $7000 scanner, come to find out my ecm was telling the injectors to stay open longer than they should. $226 to replace. not a bad deal for a new computer. could have saved a bundle if i did that in the first place...

yeah thats what i was thinking maybe the ECM but im just getting to the point where im bout to throw it away

well i bought a little tester thingy for voltage and i tested all of the connectors but when i got to the IAC connector i got nothing, i looked at the wiring and wires are showing through and you can see damage to the wires. do you think maybe this would cause what it is doing?

nevermind i figured it out the car had to be on :) :iceslolan :bananasmi