93 lumina cant seem to find problem

ok so it all started about a year ago my car started randomly dieing no common cause found. car is cold or hot still does it. started at idle (mostly stop lights) not it will just randomly do it even if driving down the highway accelerating or not car just shuts off no stutter jerk or anything sometimes it will start right back up other times it takes up to twenty min (average is about 5 min) it is a 3.1 multi port fuel injected v6 with a varible (flex E85) fuel setup (yes the exist i have one) cant find much info but alot of parts are diffrent. some of the things i have noticed are my ethanol readout is bouncing from 0% up to 45% running normal gas in it and no codes are being shown most of time when it does throw a code it is a 56 (Quad driver Module (QDM) B Fault) but it will go away and doesnt even always come on just once in awhile and will go out usually in same trip it comes on . now to the things i have done changed spark plugs and wires, pvc valve and tube for it, upper intake manifold gaskets, replaced vacum lines, cleaned EGR and new gasket, cleaned multiple ground connections, cleaned IAC and retrained idle, and possible more but i cant think of it right now and for the record the readout didnt start bouncing until i cleaned grounds and did the intake gaskets and it doesnt bounce all the time just usually when it does it will die but not always car will idle up and down but not always ... im just to the point were im wondering if the ecu needs to be replaced or if it could possible the ethanol computer that needs replace had it in a shop about year and a half ago was there for six month after it just died one day and wouldnt start they claim to had the computer rebuilt and found a wire harnes that was arcing personaly i dont beleive it at this point i have found a ecu for my car after months of searching since it is a very specific part no interchange for my car avalible oh and after i do one of the repairs from above the car will run good for 3 to 7 days till it starts doing it again i apologize for long post its late and i have spent months on these forums and just cant seem to find something that will fix my car

First of all when it won't start do you have spark and fuel pressure, basic diagnostics, will it start spraying carb cleaner/starting fluid into the intake?

First of all when it won't start do you have spark and fuel pressure, basic diagnostics, will it start spraying carb cleaner/starting fluid into the intake?

i have spark can hear the fuel pump whining when key is turned but no presure test yet some times get a 56 code but not always after a few min it will start back up havent sprayed anything in the intake ... i will pick up a can and keep in car for next time it does it

ok so still dont have presure checker but there is fuel that comes out when i press on the s valve (cant think of its name the spot were you check the presure) tried spraying carb cleaner still no go i can hear the pump when i turn the key but as normal it wont start till a couple minites go by and then starts no problem it has been stalling when i first start it and reverse about half way down drive but starts right back up and goes

i have also noticed it seems i am leaking a little oil from around my oil filter was curious to know would this be able to cause i big enough drop in presure to trigger the fuel pump to shut off and changing oil and filter in the morning

Until you check the FP anything else is a guess.

Until you check the FP anything else is a guess.

ok understood found out one of my buddys dads has one just need to get it now on the other hand though i seen a post about oil presure turning off the fuel pump would the fuel pump reset itself after a few min? i seem to have a oil leak think it is the gasket around my pan but not sure yet just something i noticed but was thinking if that caused a big enough leak maybe im loseing to much oil presure and it is killing pump to protect the car ... just a though i will hopefully have fuel test in couple of days at most

Not likely, that low an oil pressure would ruin the engine besides leaks have no effect on oil press. unless you ran it empty.

still no luck on presure test for fuel really dont think my fuel is problem though but i did replace my TPS was noticeing a hesitation at certain points in throttle presure and changed idle and hesitation changed points anyway that took care of hesitation and odd idle at start up but i have noticed my car seem to have issues when the brake is used alot and when it is used hard it is as if my booster is randomly loseing air-tight status would this be the booster it self or something causeing it (most of the time i have rock hard pedal after few pumps when car is off but other times it will not harden while car is off usually when car wont start back up)have also noticed when i push the brake pedal all the way it makes my ethanol read out jump to 45% then it goes back to zero a second later and when car wont start it is usually reading 45% then sits few min drops to 0% as soon as car starts again oh and i can start the car and it will idle in my drive way with no issues everyone i talk to doesnt think it is my fuel presure and i cant seem to get a fuel presure test done and i dont have the money to just throw away on a tester

i dont belive u have a fuel issue , if so when its fuel it will spudder and jerk before it dies, a dead kill is usually a electrical issue, have u been able to have anyone scan it and monitor the 2 crank sensors and the cam sensor? theres a 7x crank and a 24x crank sensor .. the 7x is behind the engine under the exhaust manifold and the 24x shuld read off the balancer in the front and the cam sensor is on top of the timing cover and the wires should come out and plig in in the front of the engine...:runaround:

No matter what the fp must be tested to eliminate unecessary parts replacements, there are no short cuts here. Agreed it does sound electrical, maybe.

still no luck on presure test for fuel really dont think my fuel is problem though but i did replace my TPS was noticeing a hesitation at certain points in throttle presure and changed idle and hesitation changed points anyway that took care of hesitation and odd idle at start up but i have noticed my car seem to have issues when the brake is used alot and when it is used hard it is as if my booster is randomly loseing air-tight status would this be the booster it self or something causeing it (most of the time i have rock hard pedal after few pumps when car is off but other times it will not harden while car is off usually when car wont start back up)have also noticed when i push the brake pedal all the way it makes my ethanol read out jump to 45% then it goes back to zero a second later and when car wont start it is usually reading 45% then sits few min drops to 0% as soon as car starts again oh and i can start the car and it will idle in my drive way with no issues everyone i talk to doesnt think it is my fuel presure and i cant seem to get a fuel presure test done and i dont have the money to just throw away on a tester

i would take max's thoughts and if you can spray starting fluid in it and it don't fire up i would go to coilpack next after you get f/p tested.

update ... the other day i was looking stuff over noticed my icm was lose tightened it down and now my ethanol read out has quit jumping around but still goes to 45% when car dies ... changed the crank sensor (7x i beleive on back side of block) cant seem to find other on there is a hole and a thread hole behind water pump but no sensor also looked at bottom of engine were haynes book shows there should be one by the pully nothing there i have seen it stated only 1 is required to run so maybe others were removed before i got car or it could just be another weird thing about my car idk ... when i pulled the crank sensor it smelled like seafoam and oil i recently did a crankcase treatment with seafoam and changed my oil but im not sure if the sensor should be exposed to that or not so im mentioning it sensor looked undamaged otherwise car is still running same as it did before idles inconsistantly some times it idles great other times it just cant seem to level out ... i have also noticed when i press the brake it is as if it sucks to much air out of my engine and tries to kill it then when brake is released it causes my engine to rev up (to clearify press it almost kills car let go car revs up) my personal opinin at this pint is that my ecm has been damaged and im just hopeing to to atleast replace the culprit part before replaceing it ... oh and my speedomiter has been bouncing around more often since tightening my icm back down ... is it posible that the icm being lose shocked my ecu and that is what could have started all of this since it seems nothing is altering the status of the way the car is running sorry for long post and thank you for takeing the time to look at it

think i found my problem atleast one of them i had a code 56 think im going to try and trace the ground wire now

If the variable coaxial capacitor in the VFS
fails, it will cause a code to be set in PCM memory.
With the 1991 sensor, a code 56 is stored; the
1992 and later sensors will cause the PCM to set
a code 56 (voltage low), code 57 (voltage high),
or code 58 (degraded fuel sensor). A temperature
sensor failure will set a code 64 (temperature
high) or code 65 (temperature low). The Tech 1
scan tool can be used to determine the percentage
of alcohol present in the fuel.

You are running a first generation 3.1 engine which only has the one crank sensor, on the back of engine. Generation II engines with sequential injection have both crank sensors.