3800 Help car wont stay running...

Reply
I

imported_GraFFix

Guest
  • #1
    OK last night on the way home from the mod day I was on 294 heading home...crusing at a steady 70mph not beating on it or anything just crusing.

    All of a sudden i feel the car start to slow down..I give it some gas but thats not helping. It felt like if i tried to give it more gas it was almost flooding out and rpm's would drop...if I left off it seemed to be a little smoother but still thats not helping me on the highway. Now im stranded...and to top it all off, my cell phone was dead and I left my car charger in the car ive been driving for the past 3 months :(
    So i wait for a trooper or someone to come buy..it didnt take long for a trooper to drive by and stop so i tell him the situation and he calls a tow for me...

    Luckily about 10 minutes later Jeff and Kevin are on 294 heading home from the mod day also...and see me on the side of the road and stop! I was like HOLY SHIT! So with there phone we start calling people...

    Alex says to try the fuel pump thing..so I hack my A/F gauge for a peice of wire and try to do the fix...still wont stay running. so we try all possible wire combinations on the relay and nothing...

    As im trying to fix the car on the side of the road the tow truck shows up...Kevin asks the guy how much is the tow and he was like $82 + 2 bucks a mile...hes like screw that I got AAA!! but now the tow driver is like well im here i need $50 for just coming out then...Jeff worked his pimp magic on him and offered the guy 10 bucks to just leave..and he took it. Sweet!

    Kevin gets on the phone and calls AAA and there on the way..as I continue to try and get the car running...needless to say by the time the AAA tow got there the car was still dead :( and I had it towed home for free (minus a 10 buck tip cause the guy was cool)

    So first off I need to thank a few people for helping me out in a time of need at 11:30PM on the side of 294N

    Thanks to Jeff and Kevin for stopping and also Kevin getting me a free tow home...you guys rock! and I owe you both BIG TIME!

    Thanks to Alex for trying to help me over the phone...Much appreicated bro I owe you a beer or 10

    Thanks to John and Hale for returning my calls and trying to help out also...Again, I owe you guys.

    Thanks to Mike for dropping off a fuel pump for me today as I was trying to figure out what was wrong with the car. yes...I owe you too!

    I cant say how gratefull I am for being part of this club and having such good friends who are willing to go out of there way to try and help people...

    Obviously ILGPC ROCKS!

    Now to go on with my problems...the car still isnt running. and im just trying to get some opinions on what I could look at.

    The fuel pump primes you can hear that and I have fuel pressure...

    the car starts always but will not stay running...

    I put the fuel pump resister on today that I got from the casper fuel pump hot wire kit...still didnt help....

    I swapped out the plugs today and some of them were wet with gas..after i put the new plugs in the car fired right up..ran smooth for about 10 seconds then started loosing power just like on the highway last night. but if i mess with the throttle I can keep it running a little longer but its not smooth at all and if i give it to much gas it wants to die again. eventually it will just die out even while feathering the throttle.

    I am going to now go put my DHP PCM in the take out the C-Ya PCM and see if that helps any...

    I dont think its the fuel pump..although Ill take any opinions

    I am going to try a new fuel filter tomorrow..the car sat at mikers for 3 months and dont know if the gas old gas clogged it or not...will take opinions on that too.

    the car threw no codes when it started acting up...but i was having a p0171 all week long and I thought it was my 02 sensor that went bad from the TOG install the car still drove fine it was just my O2's werent reading on my A/F gauge or my scanmaster. The thing is I was seeing p0171 and that comes back as "fuel trim system lean" but yet it seems that its running to rich..like i said a few of the plugs were wet with gas when i pulled them but that could of just been from trying to start it over and over?? opinions?

    Im just looking for any opinions....as it stands now, I probably wont be taking the car to IDD and probably hitching a ride with someone.

    Any ideas anyone has I will look into...im stumped.

    Thanks in advance
    Joe

    Back to the garage to kick the car some more :(
    Click to read more...
     
    B

    beyerch

    Addict
    Jan 20, 2009
    704
    0
  • #6
    Hey,

    Allow me to try and help.

    You said the plugs were wet, that means your getting plenty of fuel. Forget the fuel pump.

    At this point I'd suspect the following items
    - Fuel Pressure Regulator
    - MAF Sensor
    - O2 Bank 1 Sensor
    - Injector
    - PCM

    Now lets not forget about your code 'Fuel System Too Lean'. What this code is telling you is that the PCM thinks you are too lean and in order to compensate for that its adding MORE fuel. However, the PCM will only adjust so far and its hit that limit so it sets the code. Basically its telling you, hey I (PCM) think the car is too lean and even though I've added a ton of fuel, I still think you are lean, but I give up !!!! Fix me !!!

    Now lets look at the possible culprits...

    #1 - FPR (Fuel Pressure Regulator)
    - I think there's a very slim chance here. The plugs are fouled from gas; therefore, fuel is getting to the engine. Now, its possible that the FPR took a shit and is dumping in TOO MUCH fuel; however, since you are setting a LEAN code, this is not likely. If the FPR took a shit and was dumping fuel, the PCM would set a code for too RICH.

    #2 - MAF Sensor. The PCM determines mainly how much fuel to add based on the amount of air entering the engine. This is measured by the MAF. If the MAF were to give the wrong data to the PCM, the PCM could mess up and not supply enough/too much fuel to the engine. However, once again this is not likely. In the event that the MAF was reporting TOO LITTLE air, the PCM would compensate and could set the LEAN code like its doing. However, if this were the case, the plugs would not be fouled. ONce again if the maf were reporting the wrong amount of air, it would be OVERREPORTING which would result in a TOO RICH code from the PCM.

    #3 - O2 Sensor 1. At Cruise and Idle (Closed Loop), the PCM initially calculates fueling based on MAF reading. IN addition to this however, the PCM modifies that fuel decision based on feedback by this O2 sensor. If the sensor signifies to the PCM that its running LEAN, then the PCM increases fueling to compensate. IF the sensor were misreporting this A/F ratio to the PCM, its POSSIBLE, that the PCM could set a LEAN condition while in fact it could be drowning the car. This is a likely culprit. Either the sensor is bad, or bad wiring, or its quite possible that there is some type of exhaust leak right by this sensor. The sensor measures a ratio of AIR to FUEL. The higher the ratio, the more air versus fuel. If there were a leak near the sensor, it would see more air than really went through the engine and this would make the PCM think the car is leaner than it really is........

    #4 - Bad Injector / Stuck Injector. The next possible, but not likely culprit could be a bad/stuck injjector. The O2 reading from the O2 sensor is an AVERAGE reading from all six cylinders. It could be quite possible to get an average LEAN reading from this sensor when a cylinder or two is actually getting drenched in fuel by a stuck injector. This does not occur very often and since you said more than one plug had fuel on them, its not likely that more than one injector could stick and set a LEAN code.

    #5 - PCM. Since the PCM is responsible for interpreting all of the sensor signals in the car and acting on them, it is always suspect in the event something like this happens. If an injector driver on the PCM itself went bad, it could very well lock open an injector. However, this SHOULD set a RICH code, but its possible depending on the specifics on the situation.


    So the summarize, I would look at :

    O2 sensor (and surrounding area, wiring)
    Injector (and wiring)
    PCM
    MAF Sensor
    Fuel Pressure Regulator


    As far as how to test the o2 sensor, the easiest way is to .... unplug it. IF the PCM does not get data from it, it runs in a backup mode and will not rely on it. Replace your spark plugs and disconnect the sensor. DO NOT do any hardcore driving, but just let it run in idle and do some basic driving. If the problem does not occur, then you're found the culprit. (You should also pull the battery, to reset the fuel trims!)

    To test the injectors, it would really help to have a tech ii handy as you can turn on/off individual injectors at will and you can perform a power balance test.....

    To test the PCM, replace it for the time being with another unit that should run the car.

    Maf sensor, disconnect it as well and the pcm runs on backup.

    To test fuel pressure regulator, put a fuel pressure gauge on the test port. Base idle pressure should be 45 - 52 depending on whether the vacuum is applied or not. As vacuum decreases/boost increases, fuel pressure should go up. It should not exceed 1psi be 1lb of boost. i.e. if base is 52 PSI and you have 10psi boost, FPR should not exceed 62 PSI.

    That should help.

    Charles
     
    1

    12secGTP

    Addict
    Nov 10, 2008
    768
    0
    Des Plaines
  • #8
    charles`s diagnosis is very good and right on the money but I would like to offer another idea for you joe.
    I had a similar problem happen to me on my way home one night after doing all the work on my car. I did not have enough coolant in the car (less than a gallon...). the car did not overheat, did NOT set a low coolant code.. it just started to run like crap and slowly die, i lost all power. it acted exaclty like what you described. it eventually would not stay started without alot of effort.
    In essence, it went into limp home mode.
    It is a simple thing to check... make sure you have enough coolant.
     
    I

    imported_GraFFix

    Guest
  • #10
    Wow...all you guys rock! Thanks for all the imput..I will definatly look into everything that has been posted here.

    Now an update...

    I messed around with a few things last night..was kinda hard cause of easter and family stuff going on but i did manage to hit the garage for a little while.

    Swapped PCM's and now have the DHP in there...did the same thing.

    I checked the coolant and it looked full..although my overflow bottle was empty.
    When I was on the side of the road I did unplug my O2 sensor and tried starting it that way...it still did the same start up and die in a few seconds
    Im going to change the fuel filter tonight just for kicks and see if that makes a difference.

    I checked all the wireing to the O2 last night also...everything seems fine. the O2 sensor is only about 6 months old. I did get one from Steve at the mod day but its from a GT...i havent checked yet but does anyone know if a GT O2 will work or if its the same as the GTP's? I do have an Extension on it because of the TOG's I wonder if that extension could be bad or something...ill look again tonight

    Im also going to change the oil tonight...see if there is any water/coolant mixed with it :( plus it needs it...I needed a oil change when Miker took it and he was supposed to fix a oil pan leak for me so i figured he'd have to change the oil anyways...well he didnt fix it and the 3 month old oil sat in there for 3 more months without running.

    Snoop I live on the NW side of the city...close to Harlem and Irving park.

    Ill let you guys know if I find anything....and thanks again!
    Joe
     
    9

    98 TGP TOY

    TCG Elite Member
    Feb 9, 2008
    2,167
    0
    Morton, IL
  • #16
    Honestly dont see it being the O2 sensor, maybe the wiring. You said you unplugged it, and it still had problems. So that means, the problem isnt dependent on whether the O2 sensor is bad or not. So check the wiring thoroughly and then start on the MAF and FPR like charles suggested.

    Also, ACDelco.com says that the gt and the gtp sensor are the same.
     
    gtphale

    gtphale

    TCG Elite Member
    Nov 9, 2008
    1,578
    0
    Aurora
  • #17
    Man Joe was really hoping it was just a wire or something. And it still can be a short in the system somewhere. Besides the fpr and the maf i'm really not sure what else could cause you the problems. Joe what year is your car? I have a couple tb's here that I can run over there to you tommorrow so that you have good sensors on your car. Will eliminate some of the problem area's atleast.
     
    I

    imported_GraFFix

    Guest
  • #25
    No not yet...But i believe i have other problems now.

    I screwed up my fuse box while trying to do the fuel pump fix when i was on the side of the road :(

    I put the wires in the holes that Alex told me then pushed the relay/fuse back in. Well I guess the wire that I used to do this was to thick and instead of making a connection It actually pushd the pins into the fise box and now the relay/fuse doesnt make a connection.....

    So Instead of dealing with trying to fix it I need to get back to square one and get this fuse box fixed before i try to diagnose what the other problem was. Who knows the resistor fix might work but with the fuse box screwed up it could be the whole problem now...

    The thing that sucks is Ed dont have one, GMPD carrys them for 115 shipped but its going to take forever to get it to me...I checked online last night and have a few places to call today and try to get it here sooner. and also alot cheaper. well see though.

    its just my luck though...I still think its the fuel pump resistor thing...but of course i had to screw up the fuse box...try to fix one thing and break another...story of my life :p
     
    Old Thread: Hello . There have been no replies in this thread for 90 days.
    Content in this thread may no longer be relevant. Consider starting a new thread to get fresh replies.
    Receive Email Updates

    Thread Info

    Top Bottom
    Topics
    New Posts & Threads
    Garage
    Menu