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348 Error Code 1123 with no secondary air system?

Discussion in '348/355' started by HWOODMECH, Dec 22, 2018.

  1. HWOODMECH

    HWOODMECH Rookie

    Dec 20, 2018
    2
    Full Name:
    Micah Coley
    I have a South American 348 from 1991. Using the jumper cable, I have been able to retrieve code 1123 from both ecms. This seems to link to Secondary Air Solenoid Valve Relay (per my348.com). This spec of 348 does not have a secondary air system. No runners on the headers, no secondary air pump, etc. So I'm wondering what could cause the fault? Some seem to thing the Intake adjust solenoid valve under the intake manifold behind the oil filter could be the source, however, I am not sure.

    History of the car: Just bought with 10k km on the dial, however it has definitely been driven hard. Just removed the steering rack and replaced inner tie rods ($300 to a rebuilder). The car smells rich and had a horrible idle and would die upon warm engine deceleration to a stop. I found each MAF sensor off of the 383 ohm resistance, and matched those. Also the throttle body air bypass screws were completely closed, so I removed, cleaned and backed them out evenly until the engine would run (with idle air control valves removed and ports plugged), although at a 1050 rpm which is high, but wouldn't run below that. Then I found spacers on the only two o2 sensors, with small screens (as if they were trying to trick downstream o2 sensors, however this car only has the 2 upstream which are heavily relied on for fuel ratio) so I removed the spacers and replaced the o2 sensors with new bosch sensors. The car doesn't die, but it does idle high. The next step is to try to get the idle down, but the cel for 1-4 and 5-8 are both on for the same code.

    Any help would be greatly appreciated. Thank you.

    (ps. to get the check engine codes, pull the panels from behind the seats over the ecms, dig behind the wires and find a 3 wire plug on both, then jumper with a straight wire between the black (middle) wire and the grey/red wire, turn on the ignition, wait 3 sec and remove the jumper and the light will flash with one long flash and then pulses and delays for each number of the 4 digit error code and a long flash when finished)
     
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  3. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    709
    Victoria
    Full Name:
    Paul, Australia
    Id start with fresh spark plugs as it may well be possible that they are fouled which wont help with cold start idle or good general running. This is just my opinion but for years i have found that once a plug has been fouled they very rarely come good. Delete fault codes and fresh plugs and start from there. Oh and merry xmas.
     
  4. HWOODMECH

    HWOODMECH Rookie

    Dec 20, 2018
    2
    Full Name:
    Micah Coley
    I found a bad resistance value through the ecm when on for the 02 sensor. Resistance for the o2 ground (pin 10 tested ohms to pin 19 or ground on Motronic 2.7). That with the o2 spacers make me think it has a tune. I'm leaving the new o2 sensors in without the spacers, just direct into the pipe, pre cat. Smelled rich so i increased the MAF sensors to 388 each. Brought the throttle valve bypass screws adjusted, one at a time, half turn at a time, until it idled at 975. Cleaned the grounds and rewired each door with solder and insulation. Planning on making a new wire harness for each door after the holidays. They were still green when i stopped trimming wires an inch and half from the original length. Also swapped the fuel filters.

    After all this, idles incredibly smooth. Needs new exhaust bolts and doughnuts, so a little raspy but smooth, no more water from the exhaust after warm up or overly rich smell (still a little).

    Cels are still present, same code 1123 even if i use the jumper to command the clear, comes back upon second start up.

    Going to try other ecms as soon as i find some.
     
  5. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    709
    Victoria
    Full Name:
    Paul, Australia
    Pull a plug and watch a few YouTube videos on how to read spark plugs. You will learn a lot about how the engine is running from plugs
     
  6. m.stojanovic

    m.stojanovic Formula 3
    Silver Subscribed

    Dec 22, 2011
    2,074
    Malaysia - KL
    Full Name:
    Miroljub Stojanovic
    It is possible that your car originally had the Secondary Air system but that it was removed, thus the codes. Did you check for any unconnected connectors? Otherwise, on the 348, the system does not have any air pump.

    1050 rpm is the correct idle speed for the 348.
     
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  8. m.stojanovic

    m.stojanovic Formula 3
    Silver Subscribed

    Dec 22, 2011
    2,074
    Malaysia - KL
    Full Name:
    Miroljub Stojanovic
    Pins 10 & 19 are both ECU grounds and they don't seem to be related to the O2 sensor. If you connect an ohmmeter between the connector sockets for the ECU pins 10 & 19, although both go to the ground, you will get a reading of 1-2 ohms which is due to resistances along the two wires leading to the ground and resistances in the connections of the ohmmeter probes. This is quite normal and means the ground connections of the pins 10 & 19 are ok. With the multimeter at its lowest ohm range (usually 200 ohm), if you connect the probes together, you will never get 0.00 but something like 0.8 - 1.2 ohm. You should deduct this "base" ohm value from any low ohm measurements that you do. I can get 0.00 ohms reading at the lowest ohm range (with the probes connected to each other) only on my Fluke multimeter.
     

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