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  • E-Street Problems

    Last year I installed my E-Street system that I had bought the year before. It is one of the first generation units. It ran OK but did not quite have the power the carb did. There was an off idle hesitation. The accelerator pump and shot duration were increased with little effect. The initial timing is 15 deg and total is 35deg. 383 cubic inch small block chevy. MSD didtributor and coil. No CD box. Can is 231 duration. Fuel pressure 50 psi.

    Today I decided to flash the memory and start over.

    It started right up and I set the idle screw and matched the rpm on the pad. I had some trouble getting the idle speed right.. I could turn the screw and at first there was no change.at first. Then all of a sudden the idle speed would jump up a few hundred rpm. Then I turned the screw back with no effect at first then the rpm would jump down too low. After warming up, the idle speed did stabilize somewhat. After a few minutes of running with the engine fully warmed up the idle would suddenly drop without me doing any thing, and the engine would shut off. I had to restart it a few times and adjust the idle screw some more before it would keep running. By this time the engine was getting a little too hot so I shut it off for the day. I did see the the AFR for idle was 12.96. The throttle position was between 10 and 12 percent depending upon how the idle speed was adjusted. While running the exhaust seemed very rich and my eyes were burning.

    Is this idle behavior normal during the learning process or did I do something wrong?

    Is there something I am missing?

    On an older post it was mentioned that the secondary throttle screw should be adjusted slightly to raise the idle 25 rpm and then the primary idle screw adjusted to drop the idle speed back down.

    If there is a secondary idle adjustment screw I can not find it. There is no mention of this in the directions that I can see.

    I did not drive the vehicle since reflashing the memory, Just idle in the garage.

    Need ideas.


  • #2
    Originally posted by Emiller View Post
    Last year I installed my E-Street system that I had bought the year before. It is one of the first generation units. It ran OK but did not quite have the power the carb did. There was an off idle hesitation. The accelerator pump and shot duration were increased with little effect. The initial timing is 15 deg and total is 35deg. 383 cubic inch small block chevy. MSD didtributor and coil. No CD box. Can is 231 duration. Fuel pressure 50 psi.
    Could have been the timing...EFI's shoot high pressure fuel. It will get to the cylinder faster then a carburetor that depends on the the velocity principal.

    Today I decided to flash the memory and start over.
    It's always a good idea to start with a clean ECU.

    It started right up and I set the idle screw and matched the rpm on the pad. I had some trouble getting the idle speed right.. I could turn the screw and at first there was no change.at first. Then all of a sudden the idle speed would jump up a few hundred rpm. Then I turned the screw back with no effect at first then the rpm would jump down too low. After warming up, the idle speed did stabilize somewhat. That kind of sounds like a sticking TPS sensor. With the motor off. Open, and close the throttle 5 times. After a few minutes of running with the engine fully warmed up the idle would suddenly drop without me doing any thing, At 170F the system switches from running on the MAP. To now include the O2 sensor.......so must be O2 related. Fix/repair. and the engine would shut off. I believe the system would start cutting back fuel with a bad/no connection to the O2 sensor....... Always start over with a fresh tune. When repairs, or parts replaced on the system. I had to restart it a few times and adjust the idle screw some more before it would keep running. By this time the engine was getting a little too hot so I shut it off for the day. I did see the the AFR for idle was 12.96. The throttle position was between 10 and 12 percent depending upon how the idle speed was adjusted. While running the exhaust seemed very rich and my eyes were burning. Unburt fuel is either: To much OR ignited too late (advance base timing)....might have a after-burn through the exhaust....I'm just saying.

    Is this idle behavior normal during the learning process or did I do something wrong?
    The system will function properly. After some investigation, and repairs.
    Is there something I am missing?
    Hard to say. You did give some good descriptions that I was able to suggest what to look for.......but every time ( most ) problems associated with a motor dying. Was the HEI module shutting off.
    On an older post it was mentioned that the secondary throttle screw should be adjusted slightly to raise the idle 25 rpm and then the primary idle screw adjusted to drop the idle speed back down. The IAC, Idle Air Control should give you a smooth idle....If it's "adjusting" to much, and you can't get the idle to smooth out...Then think about adjusting it. The "sweet spot" will be when the IAC is adjusting the least.


    If there is a secondary idle adjustment screw I can not find it. There is no mention of this in the directions that I can see. Believe you need to look at the under side.

    I did not drive the vehicle since reflashing the memory, Just idle in the garage.

    Need ideas.
    Move throttle 5 times. Check O2 sensor, wires and connectors. Possible HEI exchange?
    This space is hermetically sealed, to keep in that old car smell

    Comment


    • #3
      I took the car for a test drive Monday. Everything worked fine. No problems like after reflashing the computer on Friday. The EFI worked great after a few miles.
      The only problem is the off idle hesitation, but it is not nearly as bad as before reflashing the ECU. I also raised the accelerator pump shot some what and it's duration before taking it for a drive. Maybe I need to go further with it. The timing is still at 15 deg initial and 35 deg total. No other changes. All plugs were checked for tightness and no fuses blown.

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      • #4
        If you have anything other than a stock cam, bump the initial timing to 18-20 degrees and add some pump shot.

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        • #5
          I will try that. The can has 231 duration. Will that much timing make the engine hard to start or cause overheating problems?

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          • #6
            That much timing is fine with fuel injection. It will not cause starting issues or overheating. With that duration camshaft, you may go as much as 22 degrees at idle and limit total timing to 34-36 depending on the fuel octane you run.

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