91 firebird wont stay running

J

JohnW1975

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HELP!!!!!

my car dose not want to stay running. seems to idle fine till it warms up then quits. when car is idling i throttle slowly and reaches around 2000 to 4000rpm, then it starts choking. when i hit the gas fast, it chokes. when the engine is hot it will stall and not start again till it cools. i have tested the fuel pressure and it reads 38.5 to 40psi when idling. from a handfull of mechanics that is fine. tested for spark (that is good), also replaced gas filter.

so i am wondering if anybody else has had this particular issue and what they did to fix it. please indicate if it is from the manual or not. thanks.. i will be posting new areas as i encounter them. here is a picture of my engine incase you need to explain a location or part..

thanks, John

35388_129165880450677_100000717987396_186140_2623237_n.jpg
 
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ok, i said forget it and decided to replace the fuel pump. and results were fantastic. ran it till it got hot and drove it for a bit.. well i parked it and an hour later decided to go out and get something to eat.. well, it started and ran just like it did before i replaced the fuel pump. i dont get it... keep in mind that it ran and drove like a dream when i replaced the pump and now runs like before... any answers?
 
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fuel filter

the fuel filter was replaced when the gas pump was..
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Fallow up7-28-10

well, tried a new fuel pump and that didn't change a thing. pressure check is at 45psi witch is good. replaced fuel regulator and it seems to stay running like crap a bit longer than last time. tried a new maps unit and that didn't do anything. tested injectors, ignition system, IAC, TPS and all seems great. what could the problem be? i am thinking its the computer but if its not then i can not return it and its back to what could be the problem? gas lines are not blocked. no vacuum leaks.. i am running out of answers

Please Help
 
Kinda sounds like a vapor lock, but never heard of a FI system doing it.Could be the gas cap(where u put gas in) leaking.Any FI car builds up a certain pressure in the tank to make it work.Just outta curiousity, have you done the check engine coding and see what pops up?
 
Update 07-30-10

so here is the full details..

Feul pump\filter, fuel pressure regulator, computer, MAP sensor, temp switch, EGR, Distri cap\rotor\wires\plugs, PCV were replaced.

ignition system, injectors, fuel pressure, IAC, TPS were all tested and\or cleaned. Also tested for vapor lock..

None of this fixed my problem. is there anything else i can try?
 
Even new parts can be bad, i would do the check engine light codes and see what it says.From what i can tell, almost sounds like a bad ground though.
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OK just answer me this. dose bad fuel injectors sometimes work then not work? will that also throw several codes? some of them being MAPS, IAC and TPS?
 
Anything electric can act this way, but i would think it would mostly miss rather than die out.Sounds like ur on the right track.If im not mistaken, i think u can ohm the injectors to test them.Since i put new parts on it, i would clear the codes and run it and see if the codes have changed any.
 
right trac?

what? dose it sound like the injectors are bad? would they work off and on when they go bad? i'm broke and running out of options and that's my only way of transportation..
 
I reset the computer and sterted it... ran like crap and it just and only gave me code 33 "map sensor" i had put a new on it and reset the computer and it still tells me something is wrong with the map sensor... any ideas?
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i had the same problem with my 97 grand prix changed pretty much every thing like you and still had problems. read on line about other cars having the same problem turned out to be the fuel pump ballast resistor..... cost about 60 bucks from the dealer easy to install and no more problems.......... hope this can be of help!!!!!
 
fuel pump ballast resistor?

jim johnson said:
i had the same problem with my 97 grand prix changed pretty much every thing like you and still had problems. read on line about other cars having the same problem turned out to be the fuel pump ballast resistor..... cost about 60 bucks from the dealer easy to install and no more problems.......... hope this can be of help!!!!!
Click to expand...

would fuel pump ballast resistor throw a code and where would i find that? my repair manual dont say anything on that
 
Mabie The Solution To My Prob!!

Well, i just put in a whole distributor assembly, new coil and plugs just to make sure they were new "what the heck" that didn't work but fired a little longer so, i finally gathered the nuggets to take the plenum apart and Ohm test the injectors and to my surprise injectors 2, 5, 6, tested around 6.? others tested at 12.8. so witched leads to me buying new ones.. one question? would that throw a map sensor code? i will post my outcome after i put the injectors in.. feel free to post till then.... Thanks to everyone so far.
 
http://www.ohmcheck.com/fuelinjectors.htm

Hope this can shed a lil light on it.Sounds like you might have some bad ones.
If it fired a lil longer then more than likely its something the car needed anyhow.
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No Need

thanks for the page refurel. didnt need it.. and i am repacing all 6 injectors with new ones and NOT refurbs.. no need to clean they will be brand new and i will be ohm testing them to just incase there might be a bad one out the litter..
 
Problem Solved!!!!

i have replaced all 6 injectors and WALLAH!!! started no problems... and i think the answer to my question earlier is YES the injectors would throw a MAPS sensor code..

I would like to ad, Thanks everyone for helping me out and the garage i had brought it to is a piece of $h!T... i don't have any knowledge of engine work at all and i had succeeded something the garage could not do... thanks again everybody:)
 
Sweet , glad you figured it out, now form now on, dont take it to a garage, just save the time n money n do it ur-self :)
 
Lol Lol Lol Lol

yea, i plan on doing it myself.. its not that frightening to take it apart now.. I have a bad habit when i work on computers, i end up with some screws left over when i get it back together.. lol... glad they don't weigh 1000lbs or more and have major moving parts...

i didn't end up with any bolts, nuts or UN-connected wires when i was finished, THANK GOD!!! all i had to do was set the timing. was tricky at first, sounded good in park but had a different response when in drive with foot on brake.. so i had to pull my E-brake and set the timing when it was in drive and now she purrs like a dream..
 
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