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Failed Leakdown....what next?

Discussion in '1st Gen. Tacomas (1995-2004)' started by KH85, Dec 7, 2022.

  1. Dec 7, 2022 at 8:10 PM
    #1
    KH85

    KH85 [OP] Active Member

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    Starting a new thread, not getting any response on the old one, here it is for reference.

    https://www.tacomaworld.com/threads/bad-maf.764069/

    Just to refresh though, its an '84 pickup with a '95 3rz swap. Got the full swap done and it will not run right, rough idle and stutters/falls on its face from idle to 3k rpm. Above 3k rpm it seems to run fine.

    C.E.L. codes-P0300, P0302, P0303, P0304 (All misfire codes)
    Compression test yeilded 132-139 psi on all cylinders
    Valves are almost all within spec., the three that arent are only +/- .001 out of spec.

    I've tried a ton of different things but nothing has worked. Just bought a leakdown tester and tested it and it seems to have failed.

    #1 is -5%
    #2 is -18%
    #3 is -18%
    #4 is -12.5%

    During the leakdown, air is escaping from exhaust, intake, and crank case. Seems to be mostly from exhaust. Nothing in the radiator.

    What should be my next step? TIA
     
    Last edited: Dec 7, 2022
  2. Dec 7, 2022 at 8:19 PM
    #2
    mechanicjon

    mechanicjon They call me "Jonny Stubs"

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    There's no way you can have that much compression and those leakdown numbers.
     
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  3. Dec 7, 2022 at 8:21 PM
    #3
    mechanicjon

    mechanicjon They call me "Jonny Stubs"

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    Do you have enough fuel pressure? Did you update the fuel pump to the later model? Fuel pressure regulator isn't leaking fuel? Fuel evap emissions hooked up?
     
  4. Dec 7, 2022 at 8:23 PM
    #4
    KH85

    KH85 [OP] Active Member

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    Edited: #2 is -18%
     
  5. Dec 7, 2022 at 8:30 PM
    #5
    KH85

    KH85 [OP] Active Member

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    Don't know what fuel pressure is. Fuel pump is later model 22re. Replaced FPR with brand new OEM unit, didn't change anything. Motor is out of a '95 and just had the old style EVAP canister like the 22re.

    Fuel related issues are really the only thing I have yet to chase down, other than the new FPR and new filter. The reason I haven't is because it runs what seems to be flawlessly abouve 3k rpm. I've yet to find anyone able to give a good reason why a fuel related issue would only effect the low end? How would it only run good at its highest fuel demand?
     
  6. Dec 7, 2022 at 9:53 PM
    #6
    mechanicjon

    mechanicjon They call me "Jonny Stubs"

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    Have you set the timing with a timing light? Sent you a pm also.
     
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  7. Dec 8, 2022 at 4:26 AM
    #7
    Bivouac

    Bivouac Well-Known Member

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    Remains to be seen I bought the tires and wheels the rest came along
    Sounds like a timing issue to me as well.
     
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  8. Dec 8, 2022 at 6:51 AM
    #8
    mechanicjon

    mechanicjon They call me "Jonny Stubs"

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    More I think about it I'm leaning egr valve evap emissions.
     
  9. Dec 8, 2022 at 5:31 PM
    #9
    KH85

    KH85 [OP] Active Member

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    Yes timing has been checked with a timing light.

    Would it not throw a code other than misfire codes if it was egr or evap?
     
  10. Dec 8, 2022 at 5:35 PM
    #10
    KH85

    KH85 [OP] Active Member

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    I did discover that the coolant temp sensor on the back of the engine is broken, so I need to order a new one. The plastic top of the sensor was cracked in half but it was still "together" and the ECM was reading the coolant temp when scanned as well as the coolant guage in the dash is/was working.

    Edit: At this point I'm I have zero hope that this is the problem. However, I've seen people say a bad coolant temp sensor can cause some weird problems. So maybe, just maybe if it was reading, but had an intermittent connection causing problems??
     
    Last edited: Dec 8, 2022
  11. Dec 8, 2022 at 5:41 PM
    #11
    mechanicjon

    mechanicjon They call me "Jonny Stubs"

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    Not always.
     
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  12. Dec 8, 2022 at 5:43 PM
    #12
    mechanicjon

    mechanicjon They call me "Jonny Stubs"

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    This motor has a distributor? Cap rotor been changed?. Have you checked pickup coil in distributor?
     
  13. Dec 8, 2022 at 5:45 PM
    #13
    mechanicjon

    mechanicjon They call me "Jonny Stubs"

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    Bushing In distributor is tight? Shaft doesn't move back and forth?
     
  14. Dec 8, 2022 at 6:04 PM
    #14
    KH85

    KH85 [OP] Active Member

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    Yes, yes, and yes. As well as new plugs (gapped properly) and wires. All checked good per FSM specs.

    I'll have to check, though I'm sure I would have noticed.

    Edit: No play in dizzy shaft.
     
    Last edited: Dec 8, 2022
  15. Dec 8, 2022 at 6:16 PM
    #15
    mlcc

    mlcc Well-Known Member

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    Your lucky the thing runs at all with a broken coolant temp sensor.
     
  16. Dec 8, 2022 at 6:27 PM
    #16
    KH85

    KH85 [OP] Active Member

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    Live Data I got during last scan.

    *All data @ approx. 1100-1200 rpm idle.

    Fuel Sys 1-CL
    Fuel Sys 2---
    Load PCT(%)-17.5 to 19.2
    ECT-186*
    SHRTFT1-1.6 to 0
    LONGFT1-0.0
    SPARKADV-12.0 to 12.5
    IAT-62*
    MAF(lbs)-.01 to .02
    TP(%)-10.2
    O2SLOC-B1S12--B2S----
    O2B1S1(v)-.20 to .870
    SHRTFTB1S1(%)- -2.3 to +2.3
    O2B1S1(v)-.190 to .230
    SHRTFTB1S2(%) N/A
     
  17. Dec 8, 2022 at 6:30 PM
    #17
    KH85

    KH85 [OP] Active Member

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    Really? That seems kinda crazy to me.
     
  18. Dec 8, 2022 at 6:34 PM
    #18
    treyus30

    treyus30 70% complete 70% of the time

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    I don't have EGR but sure sounds like bad EGR valve
     
  19. Dec 8, 2022 at 6:35 PM
    #19
    treyus30

    treyus30 70% complete 70% of the time

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    Worst case it would just stick in open loop. Should run rich.
     
  20. Dec 8, 2022 at 6:41 PM
    #20
    KH85

    KH85 [OP] Active Member

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    EGR is deleted.
     

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