TDC and Tach Sensor replacement..help | FerrariChat
Buy

TDC and Tach Sensor replacement..help

Discussion in 'Technical Q&A' started by Gast308, Jun 4, 2006.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. Gast308

    Gast308 Rookie

    Apr 22, 2006
    44
    San Jose, CA
    Full Name:
    Randy Gast
    #1 Gast308, Jun 4, 2006
    OK guys....I have changed out every component mentioned in the chats:
    Symptom - 1980 308 GTSi misses/stumbles at 2800 rpm to 3200 rpm. Also has intermitant miss at idle.
    1) Changed out plug and coil wires and extenders.
    2) Cleaned cap and rotor.
    3) Added ground wire from ECU cover to Coil bracket.
    4) Added ground wires from both ECU mounting nuts to Cover.
    5) Cleaned ECU plugs and connectors.
    6) Cleaned Coil connections
    7) Replaced all the injectors
    8) Put on new Catalytic converters

    the car still runs exactly the same!!!! Missing at 2800 to 3200rpm and intermitant rough idle.

    I bought new TDC and Tach sensors from Rutlands. When I went to change them out, I found out that my sensors do not have the "white wire" sensors with the "white two pin connector". My car has a "Green cover" over the wires and the connectors are Red,Black and White respectively for each sensor, with an "offet bullet" connection.

    Is this an older style? Do I need to cut and splice the connectors or do I have the wrong sensors?

    I am almost ready to give up and send the car out to a pro.....frustrated!!!!

    Randy
     
  2. wolftalk

    wolftalk Formula Junior

    Jan 27, 2004
    367
    san franciso area
    Full Name:
    phil
    #2 wolftalk, Jun 5, 2006
    the parts book says all three sensors on the 308gtsi are part 115019, which is interesting since they do have different colored plugs on the ends. I guess the replacement wouldn't necessarily match the plug colors.

    The QV and 328 used 119052, which had a white connector. Dunno if the sensor itself is compatible if you wanted to swap connectors, but you've definitely got the wrong parts.

    Where are you located?
     
  3. 308GTS

    308GTS Formula 3

    Dec 27, 2001
    2,223
    TN
    #3 308GTS, Jun 5, 2006
    If you still have spark at 2800 rpm then it isn't the flywheel sensors. If you loose spark on a bank than yes I would change them out.
    If everything you checked is ok then it can't be ignition related. I would now go and check the fuel side. Fuel filter, fuel pump output at idle and off idle.

    Did the plugs look ok?
    Let us know what you find.
     
  4. Birdman

    Birdman F1 Veteran

    Jun 20, 2003
    6,689
    North shore, MA
    Full Name:
    THE Birdman
    #4 Birdman, Jun 5, 2006
    Gast,
    Rather than start a new thread, you should continue this in the old one, so everyone reading it can review your troubleshooting so far.

    Here is the thread:
    http://www.ferrarichat.com/forum/showthread.php?t=105715

    308GTS, in the original thread, Gast mentioned that the tach freaked out when the car stumbled, which is a classic sign of an ignition ECU doing something funky. This is almost always one of three things:

    1. Bad ground on ECU
    2. Bad connection at one of the ECU connectors
    3. Bad crank sensor (there are 3 of them)

    He has already eliminated #1 by adding a ground strap, and #2 by cleaning all the connectors, so that leaves #3. I am pretty confident that finding and replacing the bad sensor will cure the problem.

    Gast, the sensors you got (I *think*) are the same physical size and have the same "guts" as the ones in your car, they just have different connectors. I was able to get the right ones for our Mondial from Ferrari UK. You could either contact Ferrari UK about the right ones, or crimp new connectors on the "wrong" new ones so they connect to the wiring harness. I would first pull the offending sensor(s) from the car and be sure the new one is the same physical size and fits properly.

    You can test which one is flaky by simply measuring the DC resistance of it with an ohm meter. They should be 600-800 ohms if they are good. When they fail, they go open circuit (or very high resistance). Just measure across the two contacts on the new sensors and you will see what I mean.

    Birdman
     
  5. 308GTS

    308GTS Formula 3

    Dec 27, 2001
    2,223
    TN
    #5 308GTS, Jun 5, 2006
    I agree. I didn't see or remember the first post. Agreed he should have kept it going.
     
  6. Gast308

    Gast308 Rookie

    Apr 22, 2006
    44
    San Jose, CA
    Full Name:
    Randy Gast
    #6 Gast308, Jun 5, 2006
    Wolftalk, I am located in San Jose. Thanks for the correct part number, I will call Rutlands to see if they have the correct ones and swap out.

    I measured the resistance of each sensor, the TDC sensors seem ok at 600 Ohms. The Tach sensor was intermittant as I moved the wires around..went from 600 ohms to open....maybe a bad wire or bad contact.

    After I realized that the sensored I had were wrong, I cleaned and reconnected the old ones....thinking maybe they were "dirty" and would miraculessly start working! Nope....now the tach doesn't work and one of the engine banks does not fire. Sh)@(*%@)t!

    BTW..the plugs all look good ... light tan in color.

    Thanks to all so far....you are keeping me motivated and I am seeing a small light at the end of the tunnel....hopefully not a train!
     
  7. Gast308

    Gast308 Rookie

    Apr 22, 2006
    44
    San Jose, CA
    Full Name:
    Randy Gast
    #7 Gast308, Jun 5, 2006
    I called T. Rutlands and they say the 115019 sensors are NLA. Looks like I will have to cut the wires and change the connections on the 119052 sensors. The sensor portion in the same for both. I think that will be faster than waiting on sensors from UK........More fun!

    Man.....I just want to drive this baby!!!!
     
  8. wolftalk

    wolftalk Formula Junior

    Jan 27, 2004
    367
    san franciso area
    Full Name:
    phil
    #8 wolftalk, Jun 5, 2006
    san jose, california or costa rica? If california, send me a pm if you want some help.
     

Share This Page