Page 2 of 3 FirstFirst 123 LastLast
Results 21 to 40 of 47

Acceleration problem!!! o2 sensor?

This is a discussion on Acceleration problem!!! o2 sensor? within the General Help forums, part of the LSx Technical Help Section category; if you turn the the key on and the pump primes, does the pressure stays at 35 or does it ...

  1. #21
    Senior Member JayTA98's Avatar
    Join Date
    Dec 2007
    Location
    Orlando, FL
    Posts
    3,351

    Mean Black
    1998 Trans Am

    if you turn the the key on and the pump primes, does the pressure stays at 35 or does it start to drop slowly? The other thing that I can think besides the pump itslef going bad is that the pump's flex tube having a leak.

  2. #22
    Junior Member
    Join Date
    Dec 2005
    Location
    Racine, WI
    Age
    30
    Posts
    73

    White
    1998 Pontiac Trans AM

    Is that one of those paces on the fuel pump? I mean it was bran new from the dealership..i just cant see it being bad. That would also suck considering those things are $400 and its now been a year..

    If the fuel tank was full shouldnt it not have any issues if it was a leak? Because it runs about the same on a full tank.

  3. #23
    Senior Member JayTA98's Avatar
    Join Date
    Dec 2007
    Location
    Orlando, FL
    Posts
    3,351

    Mean Black
    1998 Trans Am

    Quote Originally Posted by UC Warrior 1 View Post
    Is that one of those paces on the fuel pump? I mean it was bran new from the dealership..i just cant see it being bad. That would also suck considering those things are $400 and its now been a year..

    If the fuel tank was full shouldnt it not have any issues if it was a leak? Because it runs about the same on a full tank.
    if the pressure is not dropping then you are good. I had a brand new pump from racetronix and there was a pinhole in the flex tube. The pressure will build up but then as soon as the pump finish priming it will start to drop. I didn't noticed until I install it. You can easily cut the flex tube with the fuel tank when installing the pump if not careful.

  4. #24
    Junior Member Jager686's Avatar
    Join Date
    Jul 2009
    Location
    Redwood Falls, MN
    Age
    30
    Posts
    94

    HOT RED!!
    1994 Firebird

    I have a similar problem but the shop told me my car is running rich, but also my uncle told me it could be the fuel pressure regulator
    NO BALLS -> NO LIFE
    1994 V6 Salvage FIREBIRD
    Full 98-02 T/A Body and T-Top Conversion Completed..
    West Coast Creations Hood
    American Racing Thrust Rims 16"
    Engine swap next year debating wat engine
    Build your own car like a man, dont be a pussy and buy one!

  5. #25
    Junior Member
    Join Date
    Dec 2005
    Location
    Racine, WI
    Age
    30
    Posts
    73

    White
    1998 Pontiac Trans AM

    First i'd like to mention i really appreciate everyone's help! I love this forum.

    I went back to the fuel pump and did realize some fuel residue (wetness looking) all around the 5 nuts that hold the pump down. This would explain the fumes i've smelled. After opening it looks like the seal sort of broke. It snaps back together but it's supposed to be sort of glued together all the way around and its not. I'm assuming pressure builds in the tank? So if the seal is bad pressure may be low? All i know is it took me 30minutes to even try and "reset" the pump back in without one side being forced down....

  6. #26
    Senior Member JayTA98's Avatar
    Join Date
    Dec 2007
    Location
    Orlando, FL
    Posts
    3,351

    Mean Black
    1998 Trans Am

    I don't think that has to do with your fuel pressure issue. The tank is vented so is not pressurized. The broken seal will cause fumes and fuel to leak. Did you had a chance to check the voltage at the pump? Did you replace the fuel filter? Did the pump tube looked ok when you pulled it out?

    A small trick when you putting the pump back is to use a wire hanger close to the end of the pump and pull on it to retract the pump spring. make sure you put the wire on the metal frame. It will go in alot easier, the remove the wire. I know it can get tricky.
    Last edited by JayTA98; 05-11-2011 at 07:21 PM.

  7. #27
    Junior Member
    Join Date
    Dec 2005
    Location
    Racine, WI
    Age
    30
    Posts
    73

    White
    1998 Pontiac Trans AM

    I didnt actually pull the entire thing out but i could. Once i saw that seal sort of damaged i assumed thats what it was. How do you check the voltage at the fuel pump?

    I also cant check the pressure because no where in town do they rent out a gauge that fits on 96+

    That hint makes a lot of sense! Thanks for the info.

  8. #28
    Senior Member JayTA98's Avatar
    Join Date
    Dec 2007
    Location
    Orlando, FL
    Posts
    3,351

    Mean Black
    1998 Trans Am

    Quote Originally Posted by UC Warrior 1 View Post
    I didnt actually pull the entire thing out but i could. Once i saw that seal sort of damaged i assumed thats what it was. How do you check the voltage at the fuel pump?

    I also cant check the pressure because no where in town do they rent out a gauge that fits on 96+

    That hint makes a lot of sense! Thanks for the info.
    just unplug the electrical plug on top of the fuel pump and put the volmeter leads inside the plug. now have someone put the switch to "on" position and watch the voltmeter. you should see 12v for a few seconds(priming phase).

    Do you have a trap door or you need to drop the tank to access the fuel pump?

    If have to drop the tank then leave the voltmeter leads in the electrical plug. Now attempt to start the vehicle (of course it won''t since the fuel pump is disconnected) and look for 12v at the voltmeter while the car is cranking.

    If you have a trap door do the above and then remove the volmeter leads. plug the electrical wire back to the fuel pump. push the test leads in the back of the electrical plug enough that you can get the voltmeter to read. you can also puch the leads against the wire insulation until they make contact with the wire. Start the car and check the voltage while is at idle and while giving it some gas. you should have 12v.

    you mention that you replace your filter last summer when you replaced the fuel pump? That seems like a long time. I would replace it anyway since you can't get a fuel pressure gauge. That will rule out that part. you really need to find out the fuel pressure. How did you got the 35 psi that you mention before? I bought my gauge off ebay for like $35 is a good tool to have.
    Last edited by JayTA98; 05-13-2011 at 06:45 AM.

  9. #29
    Junior Member
    Join Date
    Dec 2005
    Location
    Racine, WI
    Age
    30
    Posts
    73

    White
    1998 Pontiac Trans AM

    So i know its been a while since this thread but the issue was never fixed. It worked in the last summer and i was gone in ireland so i left it at that. The starter is out now (or its not cranking over) so ill replace that this weekend and next week start on the fuel issue.

    I had a fuel pressure reg i bought from the store now so im good. Also have a multimeter. Heres what im going to do.
    1.replace starter
    2.check voltage at the trap door of the pump for 12v- (while its off/on/and idle?)
    3.check the fuel pressure at the rail off, idle, and run.
    4. I think ima replace the regulator anyway just incase.

    Missing anything?

  10. #30
    Member SuperSSguy's Avatar
    Join Date
    Jul 2012
    Location
    NorCal
    Posts
    979

    Sunset Orange Metallic
    2002 Camaro SS M6

    Quote Originally Posted by 35th-ANV-SS View Post
    The MAF is right before the throttle body. Or, just after your lid. It is connected to the accordion bellows. At least on the 00-02's it is.

    You disconnect it (one wire) and unbolt it (should have a metal clamp on both ends of it) and clean it using MAF cleaner, which you can buy at Autozone.

    Click for full size

    Both P0174 and P0171 are usually MAF related. Your MAF is what monitors the amount of air coming into the engine. A dirty MAF will not read air properly, which will cause your PCM to either a) dump more fuel then what is required (running rich) or b) reduce the amount of fuel which would cause a lean condition.

    Running lean is NOT GOOD.
    Will running lean cause hi or low Nox levels? and other then a meter how would you know if your running lean?

  11. #31
    Junior Member
    Join Date
    Dec 2005
    Location
    Racine, WI
    Age
    30
    Posts
    73

    White
    1998 Pontiac Trans AM

    alright so for those who are still with me or need a refresher..here is my issue: it drives normal until i give it a lot of gas. when this happens (such as passing someone on the interstate) i often get extreme boggin, terrible gas mileage, and engine knocking. it fices itself after being shut off for a while. the pressure with key turned to ignition is 0, idle is 24, running is 24 but goes as low as 22. volts going to the pump reads 5.0 while priming.

  12. #32
    Member SuperSSguy's Avatar
    Join Date
    Jul 2012
    Location
    NorCal
    Posts
    979

    Sunset Orange Metallic
    2002 Camaro SS M6

    ^ Check the engines knock sensor? or maybe its a hot soak issue? Fuel pump and/or fuel filter? What octane gas are you using?......

  13. #33
    Junior Member
    Join Date
    Dec 2005
    Location
    Racine, WI
    Age
    30
    Posts
    73

    White
    1998 Pontiac Trans AM

    I'm using Premium Gasoline 93 Octane and 50% of the time contains ethanol. No idea how to tell if it's a hot soak and a quick google search didn't explain anything that I'm seeing. Although I could probably use a coolant flush..

    The fuel filter was brand new when I did the pump. I can replace it again for safe measures though...

    How do I check for bad KS?

    I pulled the pump and don't know what to do/look for. The lines are fine, no signs of holes or cuts. I did notice one of the metal lines coming from the pump now leaking fuel near the welded spot and I believe i may have cracked it taking it out last time but I don't think thats the issue.

    Here was the last list I had when getting the computer ran:

    MASS AIR
    02 b1s1/b2s1
    bank 1 and 2 lean
    EVAP small leak

    The MAF was cleaned, all 4 O2 replaced.

  14. #34
    Senior Member JayTA98's Avatar
    Join Date
    Dec 2007
    Location
    Orlando, FL
    Posts
    3,351

    Mean Black
    1998 Trans Am

    Quote Originally Posted by UC Warrior 1 View Post
    alright so for those who are still with me or need a refresher..here is my issue: it drives normal until i give it a lot of gas. when this happens (such as passing someone on the interstate) i often get extreme boggin, terrible gas mileage, and engine knocking. it fices itself after being shut off for a while. the pressure with key turned to ignition is 0, idle is 24, running is 24 but goes as low as 22. volts going to the pump reads 5.0 while priming.
    You are having a pressure and voltage issue. I will start checking the voltage first. You should be getting 12v at the pump even at priming. Do you installed a wire harness kit or are you using the stock wiring? Also where are you checking for voltage at? You should check at the top of the fuel pump at the plug. You should have 12v at the relay as well one terminal is 12v constant from battery power and then one will be signal from the ignition switch, the other two: one goes to the fuel pump and then one for ground.

    If the pump is not receiving 12v it will cause low fuel pressure. Have you check the voltage at the fuel pump while the car is running?
    Last edited by JayTA98; 06-04-2013 at 06:38 AM.

  15. #35
    Senior Member JayTA98's Avatar
    Join Date
    Dec 2007
    Location
    Orlando, FL
    Posts
    3,351

    Mean Black
    1998 Trans Am

    also your question about the low coolant light coming on. It only comes on if the coolant level is low. If you check the radiator and the coolant level is normal then the sensor is bad or dirty. I also have this issue and I pulled the sensor to clean it. It worked good for a few days and started doing it again and I have normal coolant level. You can either order a new sensor(around $35-$45) or simply unplug the cable going to it.

    I believe 98 was the only model with this light and it was later eliminated. I just have the habit of checking the car fluids every weekend so I find out if it's low. Replacing the sensor is very simple.

  16. #36
    Junior Member
    Join Date
    Dec 2005
    Location
    Racine, WI
    Age
    30
    Posts
    73

    White
    1998 Pontiac Trans AM

    I'm using stock wiring, the only thing I did was change the fuel pump with a GM manufactured one (OEM?) I was checking voltage at the removable clip at the top (the black one, I'm assuming the wiring harness?) Anyway, the grey one is what i found to be the 12v. I tested it and it came out to 13.5V and assuming this is correct. It's only 12 while running and 0 when off. IMG_20130607_155236_923.jpg

    But yeah that light hasn't come on for a while..so not too worried.

    Anything else? Can it be the evap leak? In the photo above you can see that the fuel line on the left is where i noticed that fuel coming from. I can just JB weld the whole/crack assuming there is one. [BLUR][/BLUR]

  17. #37
    Senior Member JayTA98's Avatar
    Join Date
    Dec 2007
    Location
    Orlando, FL
    Posts
    3,351

    Mean Black
    1998 Trans Am

    yeah the voltage is fine at the plug at the pump. having that said you have fuel pressure issue. you said you changed the fuel filter? did you replaced the fuel regulator?

    have you check the fuel pressure whe it primes(car off) and when you turn the car off? does the pressure holds or it drops quickly?

  18. #38
    Junior Member
    Join Date
    Dec 2005
    Location
    Racine, WI
    Age
    30
    Posts
    73

    White
    1998 Pontiac Trans AM

    I replaced the fuel filter two years ago when I replaced the pump. I've put about 5k miles on it. Assuming your talking about fuel pressure regulator, attached to the pump? No, this was replaced with the entire unit. Which makes me think a little because I'm wondering how i plugged the electrical harness in without dropping the tank again. That connection is pretty far back I thought.
    I thought I checked pressure at off and on but will check again right now.

    Fuel Pressure check:
    Car off-0PSI
    Ignition on-jumps to 12 and then back down to 2ish
    Car started-24PSI but after giving her some throttle it falls back to 22 and the pump winds louder for 2 seconds. That's it.
    Last edited by UC Warrior 1; 06-07-2013 at 04:59 PM.

  19. #39
    Senior Member JayTA98's Avatar
    Join Date
    Dec 2007
    Location
    Orlando, FL
    Posts
    3,351

    Mean Black
    1998 Trans Am

    check the pressure when the car is off. just turn the key to on so it primes and watch the gauge. it should hold pressure. check the same after you turn the car off it should hold pressure. keep the gauge connected at all times while you check.

  20. #40
    Senior Member JayTA98's Avatar
    Join Date
    Dec 2007
    Location
    Orlando, FL
    Posts
    3,351

    Mean Black
    1998 Trans Am

    opps sry you did post results. what about when you turn the car off? does it hold? from your results it almost sounds the corrugate fuel line from the fuel pump inside the tank Is cracked causing you to lose pressure

Page 2 of 3 FirstFirst 123 LastLast

LinkBacks (?)

  1. 06-08-2013, 10:37 AM

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. BIG PROBLEM- Please Help (no acceleration)
    By laserredgt in forum General Help
    Replies: 17
    Last Post: 07-31-2010, 06:50 PM
  2. Help: o2 sensor problem
    By 01ssSLP in forum General Help
    Replies: 9
    Last Post: 04-24-2008, 08:54 AM
  3. O2 sensor problem
    By homer311 in forum External Engine
    Replies: 7
    Last Post: 08-18-2006, 01:11 PM
  4. The O2 Sensor Problem That Doesn't Go Away!!!
    By jdubbs928 in forum General Help
    Replies: 6
    Last Post: 07-31-2006, 06:11 PM
  5. Sensor Problem
    By HighBallLS1 in forum General Help
    Replies: 4
    Last Post: 10-29-2005, 09:14 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •