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Thread: 2001 S10 L31 swap show stopper

  1. #1
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    Unhappy 2001 S10 L31 swap show stopper

    Sup folks, first time posting but I've run into a pretty show stopping problem I can't figure out. My engine will not idle or run worth a snot.

    The truck; 2001 Chevy S10 V6
    The engine; 0 miles L31 5.7L V8 running stock fuel injection with a MPFI spider upgrade.
    The PCM setup; Stock S10 411 running a 2002 Express 1500 engine and engine diag. segments with the rest of the PCM running stock S10 segments (Transmisson, etc), VATS disabled.

    The Problem; My truck will not idle by itself, it bucks and shakes like its misfiring like mad. Its hard to start sometimes and will not rev past 3,000 without backfiring out of the exhaust.

    Codes; p0200 code is the main cuplrit. I have a CASE sensor code because I've not performed the learn yet due to the engine not able to maintain smooth operation. I have an EVAP solenoid code but that is imaterial to the engine issue and a fuel level sender range code.

    What I've done thus far (All parts are new);
    1. Checked basics like spark plug wire order, connectors seated.
    2. Checked for injector pulse on each injector in spider harness. (All are good)
    3. Traced each injector ground to PCM and for continuity. (All checked good)
    4. Checked for 12v on each injector. (All checked good)
    5. Check Camshaft retard in my HP tuner (1.8 degrees, spec is 0-2 )
    6. Checked fuel pressure on Key On. (55 psi)
    7. Setup my HP tuner to watch for a misfire, PCM recorded zero misfires
    8. Disabled fuel pump, poured about a cup of gas into the throttle body and started engine. It idled for a brief second or two but ran better.
    9. Started engine, and made sure each pin in the spider connector was properly seating into the fuel spider.

    EDIT:
    Pulled all the plugs, very sooty/black except for #4 which was clean.

    The engine still shakes the whole truck. When I first fired it up after flashing the PCM it ran WONDERFULLY; https://www.youtube.com/watch?v=JQbE...EE05DC83BD2295

    I'm stumped, any help tracking this down would be very appreciated.
    Last edited by Kotaru; 11-30-2014 at 01:02 PM.

  2. #2
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    p0200 is injector control, if cylinder 4 is clean I would start proving out its ground/pcm wire if your sure it had 12v.

  3. #3
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    Quote Originally Posted by mecanicman View Post
    p0200 is injector control, if cylinder 4 is clean I would start proving out its ground/pcm wire if your sure it had 12v.
    Alright, poked a little more.


    1.Removed upper intake manifold. Re-installed fuel rails and pressurized fuel system. No visible leaks.

    2.Applying straight ground and 12v to #4 injector sprays a nice uniform looking cone then closes when ground is removed. Multiple attempts showed good visual operation.

    3. Ohm check on injector is 12.8 on my 200 scale, I cant find a factory spec to check it with.

    4. Continuity from injector harness to plug connector on top of the spider all checks good.

    5. Re checked #4 ground from harness connector to PCM and it is good.

    So what I'm seeing is that everything is good.

    FYI my pinouts on my blue connector are a 2001 Chevy Express 1500 5.7 from ALLDATA;

    Injector #1 is on pin #36
    Injector #2 is on pin #3
    Injector #3 is on pin #4
    Injector #4 is on pin #43
    Injector #5 is on pin #76
    Injector #6 is on pin #37
    Injector #7 is on pin #44
    Injector #8 is on pin #77

    All of these wires test good from harness connector to pcm.

    EDIT: 2001 and 2002 pinouts seem to be the same.
    Last edited by Kotaru; 11-30-2014 at 03:02 PM.

  4. #4
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    Its dark now, put the intake all back together with the cleaned up plugs and nada still pops and runs like a dog. I'll start it tomorrow again and record/upload a data log.

  5. #5
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    You left out the most important part of your post. The Tune. Glad you checked most of the basic mechanicals. But most people are going to need the tune settings to verify that part of the puzzle is correct. I have done 6 411 swaps on s10 trucks with no major issues. Yours being a 2001 indicates it had the 411 pcm stock from the factory. I dont believe you have a tune issue but its good to have a few sets of eyes verify it.
    98 s10 5.3 5spd.

  6. #6
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    Also i do not see anything saying you have the cam crank corelation set correctly. The distributors on these engines are non adjustable and it needs to be set via scan tool. Did you perform that procedure? It is a very important step. EDIT. oops just saw you already checked that. sorry
    98 s10 5.3 5spd.

  7. #7
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    What are the o2 sensors reading when it is running rough?
    98 s10 5.3 5spd.

  8. #8
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    My guess the distributor is in wrong. distributor is off by a significant amount. Did you install it per the GM service manual?
    Last edited by 98S10; 11-30-2014 at 06:18 PM.
    98 s10 5.3 5spd.

  9. #9
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    Quote Originally Posted by 98S10 View Post
    You left out the most important part of your post. The Tune. Glad you checked most of the basic mechanicals. But most people are going to need the tune settings to verify that part of the puzzle is correct. I have done 6 411 swaps on s10 trucks with no major issues. Yours being a 2001 indicates it had the 411 pcm stock from the factory. I dont believe you have a tune issue but its good to have a few sets of eyes verify it.
    I'll upload the tune and my data log tomorrow afternoon. Tune is pretty simple stock segment swaps with VATS disabled.
    Let me describe how it runs a little more clearly. The engine is hard to start and will not start unless given a small amount of throttle. If given no throttle it will buck and pop like its trying but die once you let off the starter. You have to give it throttle to keep it running, it will then badly buck and shake the truck while you feather the throttle to keep it running. Stalls under any kind of load.

    Quote Originally Posted by 98S10 View Post
    What are the o2 sensors reading when it is running rough?
    o2 sensors are not hooked up right now since I'm fabricating my y pipe. They were hooked up the day before and removed as a trouble shooting effort. No change.

    Quote Originally Posted by 98S10 View Post
    Also i do not see anything saying you have the cam crank corelation set correctly. The distributors on these engines are non adjustable and it needs to be set via scan tool. Did you perform that procedure? It is a very important step. EDIT. oops just saw you already checked that. sorry
    Its all good.

    Quote Originally Posted by 98S10 View Post
    My guess the distributor is in wrong. distributor is off by a significant amount. Did you install it per the GM service manual?
    TDC on engine. I aligned paint mark with dimple on the gear, turned flat side towards the front of the engine and installed. The rotor was pointing to the #8 on the dizzy. Using VCM scanner I checked my Camshaft offset and turned the dizzy until I was within the 0 to 2 degrees and tightened down.
    Last edited by Kotaru; 12-01-2014 at 12:05 AM.

  10. #10
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    If you were truly at tdc and put distributer in pointing at #8 you have it in wrong.

  11. #11
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    Quote Originally Posted by mecanicman View Post
    If you were truly at tdc and put distributer in pointing at #8 you have it in wrong.
    http://www.gmtruckcentral.com/articles/distributor.html

    Far as I can find how to setup and stab it.

  12. #12
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    Sorry it took me longer to get the log and tune. It seems when I try to get home early from work everything goes sideways.

    s10MODME.hptUse me.hpl

    I noticed two things different from last time I idled the truck. First off my KS signal is working now, and secondly my RPM indicator has stopped working. The tach works by my scanner is not picking it up for some reason.

  13. #13
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    WP_20141206_002.jpg
    WP_20141206_006.jpg
    Brought my engine to TDC, everything matches up.
    Disconnected the MAF to make the PCM run off the fuel tables to no effect.
    Disconnected EGR solenoid with no effect.
    Opened the PCM to see if there was something burnt/popped and didn't see anything visually.
    I've gone over my wiring several times and it all checks out, my timing is within range.
    My scanner is no longer picking up any RPM signal or ECT or IAT (They show -40F) signals. But my truck gauges do show RPM and ECT.
    Still have P0200 even after verifying my wiring and injector impedance within range.
    Moved back to an older tune I first started the truck on and it had no success.

    I'm clueless now, bad PCM?

  14. #14
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    Think I found it, #4 plug was the hint. Zero compression on that cylinder. Game over.

  15. #15
    Bummer. Whats up with that on a zero mile motor? Sold as a misrepresented deal or did a machine shop screw it up?

  16. #16
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    Quote Originally Posted by rpturbo View Post
    Bummer. Whats up with that on a zero mile motor? Sold as a misrepresented deal or did a machine shop screw it up?
    Sorry crazy late reply, we suspect it was the head since they were used and according to our leakdown we had air coming back up into the intake. Machine shop sold me the short block which is fine. I'm just finished putting it all back together, we will try to start it up again soon.