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Thread: NON-VVT L92, First Drive, Ran Hot

  1. #41
    Tuner in Training
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    Ok, here's the latest. Excessive crankcase pressure seems to be a plaguing bane in my rear. I now have been able to use a ball valve to get the pcv into a 5 in mg vacuum. I need to find a permanent solution, probably an AER vacuum regulator. I feel like the overheating issue might be due to insufficient low rpm flow from my stock water pump (brand new ACDelco Mechanical Water Pump 19253263, Summit Part Number: ADO-252-901, thermostat: GATES 34198S). After another cooldown and oil change, I got my O-scope out and checked the injector and coil control circuits.

    Injector 2(Dead):
    https://drive.google.com/file/d/1dGz...ew?usp=sharing

    Injector 6(Not Dead):
    https://drive.google.com/file/d/1SRh...ew?usp=sharing


    The coil was getting a signal, I just didn't take a picture of it because I was also trying to keep my crankcase pressure from popping my seals again. I think tomorrow I'll backprobe the ECM to see if the injector control signal is dropping off there. That should put all of that to rest.

    Otherwise, here is latest log of the latest cold start: https://drive.google.com/file/d/16c2...ew?usp=sharing
    Last edited by 7.5in.300BLK; 6 Days Ago at 09:49 AM.

  2. #42
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    Quote Originally Posted by gtstorey View Post
    I?m pretty sure that is correct.
    I missed this, and I wondered if that might be the case. If it is, then what is actually what?

  3. #43
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    Quote Originally Posted by DanN View Post
    Did you do any wiring on the harness? Is it possible you got some injector control wires swapped? In any case, I'd still be looking for power at the injectors.
    The only wiring modification I did was removing the phaser wires from the cmp harness and hooked the L92 cmp connector to the LS3 cmp sensor. Otherwise all the wiring is unchanged.

  4. #44
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    Ok, it's been a long day.

    I hooked up the oscilloscope, took the back cover off the ECM x2 connector, and probed pins 17, 18, 19, 20, 37, 38, 39, and 40. Each had a clean injector signal on it. So I went back over and probed 2, 4, 6, and 8, all were getting the signal. I then unplugged all the right bank injectors and got no response from the engine. Then it hit temp and the bank 2 lean went away. I cleaned up the ground behind the power steering pump. I loosened and retorqued the exhaust manifolds. I took the fuel rail off and checked to see if the injectors were clicking. I did a leak down test on the entire engine, none had more than a 12 psi differential from 100 psi. I have solid compression in the whole engine. Bank one runs fine enough to tune, and I could start tuning after it warms up and stops running lean, but it just doesn't make any sense.

  5. #45
    Tuning Addict edcmat-l1's Avatar
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    Quote Originally Posted by 7.5in.300BLK View Post
    Ok, here's the latest. Excessive crankcase pressure seems to be a plaguing bane in my rear. I now have been able to use a ball valve to get the pcv into a 5 in mg vacuum. I need to find a permanent solution, probably an AER vacuum regulator. I feel like the overheating issue might be due to insufficient low rpm flow from my stock water pump (brand new ACDelco Mechanical Water Pump 19253263, Summit Part Number: ADO-252-901, thermostat: GATES 34198S). After another cooldown and oil change, I got my O-scope out and checked the injector and coil control circuits.
    Quote Originally Posted by 7.5in.300BLK View Post
    Ok, it's been a long day.

    I hooked up the oscilloscope, took the back cover off the ECM x2 connector, and probed pins 17, 18, 19, 20, 37, 38, 39, and 40. Each had a clean injector signal on it. So I went back over and probed 2, 4, 6, and 8, all were getting the signal. I then unplugged all the right bank injectors and got no response from the engine. Then it hit temp and the bank 2 lean went away. I cleaned up the ground behind the power steering pump. I loosened and retorqued the exhaust manifolds. I took the fuel rail off and checked to see if the injectors were clicking. I did a leak down test on the entire engine, none had more than a 12 psi differential from 100 psi. I have solid compression in the whole engine. Bank one runs fine enough to tune, and I could start tuning after it warms up and stops running lean, but it just doesn't make any sense.
    You have a mucked up motor sir. Put the o-scope down and do a compression and leak down test. I'm betting your dead cylinders really are dead.

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  6. #46
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    Did you check for power on the pink? The injectors don't use an external ground - the ECU triggers them to fire with the ground. They should have constant 12 with the ign on.

  7. #47
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    Quote Originally Posted by DanN View Post
    Did you check for power on the pink? The injectors don't use an external ground - the ECU triggers them to fire with the ground. They should have constant 12 with the ign on.
    14.6V on the pink. I checked them at the same time I was checking for signals.

  8. #48
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    Quote Originally Posted by edcmat-l1 View Post
    You have a mucked up motor sir. Put the o-scope down and do a compression and leak down test. I'm betting your dead cylinders really are dead.
    Hey edcmat,
    I did a compression test before I even started checking anything else. I had 180 psi on all the cylinders. I also did a leak down test. I?|I post the results at the bottom of this. If you really think my engine is messed up, please let me know your thoughts on how you?ve come to this conclusion. The last thing I want to do is pull the motor again, tear it down to find nothing wrong.
    Cylinder
    Observed Pressure
    Leakage % = (100 - psi)
    1
    91 psi
    9%
    2
    88 psi
    12%
    3
    92 psi
    8%
    4
    92 psi
    8%
    5
    90 psi
    10%
    6
    91 psi
    9%
    7
    90 psi
    10%
    8
    89 psi
    11%

  9. #49
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    Name is Dustin I have almost the exact same problems and the exact same issues... I have a L92 2008 Cadillac .. I changed out the vvt and phazer . Fresh motor you have my attention.
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