Great find, but need help

Discussion in '4X4 Truck Talk and Repairs' started by steve_b124, Jul 27, 2009.

  1. steve_b124

    steve_b124 New Member

    Messages:
    461
    State:
    south carolina
    I found a 1987 S10 Blazer 4X4 with a 2.8L automatic that was a 1 owner truck with 98k miles. The lady that bought it new died and her son let it sit for 3 years. There are no dents, no scratches, no rust anywhere. The interior is pretty good. The paint is good. This looks like a good deal for my 16 year old's first truck.

    After 3 years of sitting, it wouldn't start DUH! The son decided to junk the truck. I bought it, with title from him for $300. So far, I have dropped the gas tank, emptied out the old gas, blew out the fuel lines, replaced the fuel pump, sock and filter and added a tank of high test. That got her running, but a freeze plug failed, so I pulled the engine and replaced all of the freeze plugs (3 were behind the bell housing). She now starts and idles great, but if I give it any gas it bogs down and will not go. I pulled the injectors (TBI) and cleaned the screens, same problem. I pulled the catalytic converter, same problem. I unplugged the MAP sensor and she runs great. So I installed a new MAP sensor and have the original problem. Unplugged runs good, plugged it won't go. Not a knock or rattle anywhere in the motor, just got a no go bug.

    I want to get it fixed, soon. I don't really know where to go from here. I wonder about the throttle position sensor, but do not know how to test it. I have a VOM but am unsure of what I should read.

    It may not even be the TPS, but I'm out of my league here, any tips?

    Thanks and God Bless All,
    Steve
     
  2. Catmanblues

    Catmanblues New Member

    Messages:
    2,224
    State:
    S.E Ohio
    Now that's a strange one there. Unplugging the map sensor an it runs fine?
     

  3. smokey869

    smokey869 New Member

    Messages:
    966
    State:
    frederickt
    well unplugging the map sensor will make the engine run a bit richer than normal, could be a couple different peoblems, have you checked the fuel pressure since you replaced the pump ? the pressure regulator is in the throttle body and could be bad, it could be the throttle position sensor, but it would normally turn on the check engine light and set a code, usually a code 22 or 23, if you have a good garage locally it might pay to have them run a scanner on it, i had one a while back with basically the same symptoms and no engine light all looked good on the scanner till i got to the coolant sensor, was reading about 300 degrees and engine wasnt even warm, ended up the computor itself was bad, just may save you some money to get it checked out before replacing a lot of parts that are probably ok, you might check on the fuel pump you got also, replaced one last week and the owner had just replaced it, the pump they gave him was for the 4 cylinder engine not the v6, and new doesnt always mean good either:angry: grrrr chinese n mexican built parts lol
     
  4. Rollinunknown

    Rollinunknown New Member Supporting Member

    Messages:
    2,286
    State:
    Missouri
    i deal with cars 5-6 days aweek... 95% of the time on a no start after someone changed the pump they didn't install the pickup tube right or a line is pinched off.

    if it was me i would drop the tank clean all grounds for the pump also get a Fuel pressure guage from a local autoparts store its very easy to install and can save you big $$$ ... It can have enough fuel pressure at idle to run like a champ but as soon as you step on it .. it dies.

    Im sure that truck should have at least 38/42lbs at idle .You could also try runing your own power sorce to the pump from the battery to check it .

    2d would be the fuel preure Regulator the diaphram always fails on the 2.8.
    http://shop.advanceautoparts.com/we...r-BWD_3464687-P_484_R|GRPFUELAMS_674036708___
     
  5. steve_b124

    steve_b124 New Member

    Messages:
    461
    State:
    south carolina
    Thanks guys,

    I ran the codes last night, got 4 of them back. I think they were 13, 23, 33, 44. That's from a poor memory - got them written down in the truck. All of them pointed to the oxygen sensor. I will replace it and go from there. Funny thing, the codes did not change after plugging the MAP sensor back up and running the truck for a few minutes. It seemed to run good with everything plugged up, so I tried to drive it this morning. Got about 100 yards till I had to stop and unplug the Map sensor again.

    Thanks,
    God Bless All,
    Steve
     
  6. smokey869

    smokey869 New Member

    Messages:
    966
    State:
    frederickt
    well the 13 and 44 are oxygen sensor codes, 44 is lean exhaust, the 33 is the map sensor from being unplugged more than likely, the 23 is the tps (throttle postion sensor) it may need and oxygen sensor but im betting that doest fix your driveability issue
     
  7. steve_b124

    steve_b124 New Member

    Messages:
    461
    State:
    south carolina
    You're right, new ox sensor and same old same old. Gettin tired of buying sensors.