winter project for the 328---- Tach? | FerrariChat

winter project for the 328---- Tach?

Discussion in '308/328' started by Fiat4Fun, Oct 8, 2013.

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

  1. Fiat4Fun

    Fiat4Fun Formula Junior

    Jul 1, 2008
    312
    Sunriver OR
    Full Name:
    Bob
    Howdy,
    Working on getting a plan to do a few projects my 1989 328 over the winter. One that I think I should address is the tach. It reads low every once and while, so I assume it will fail sometime soon? I have checked out the threads on the subject, and it seems to be a common issue. Removal seems fairly easy, but still trying to decide on a few things. Should I remove the wheel or lower the wheel? I am familiar with Palo Alto Speedo shop, as I used them twenty years ago to fix a 240z tach. I see older threads that say they do a great job, others, not so much. Anyone have some recent experience with getting their tach done? Any advice is greatly appreciated.
    Thanks
    Bob
     
  2. Elentinos

    Elentinos Formula Junior

    Sep 8, 2011
    296
    Netherlands
    Full Name:
    Erwin
    Did you check the wiring to the tach? I also had a tach that was reading low sometimes. I cleaned the wiring connectors in the engine compartment above the left rear fender. That cured my problems.
     
  3. FasterIsBetter

    FasterIsBetter F1 Veteran

    Jul 22, 2004
    5,844
    NoNJ/Jupiter FL
    Full Name:
    Steve W.
    Ditto on cleaning the connectors. I had an intermittent tach on my 328 when I got it. I cleaned the connector at the engine and no more problem. Check all the wiring, clean all the connectors, and then verify that it is, in fact, the tach. No reason to pull the tach and send it out if the source of the problem is elsewhere.
     
  4. Fiat4Fun

    Fiat4Fun Formula Junior

    Jul 1, 2008
    312
    Sunriver OR
    Full Name:
    Bob
    Interesting ;-)

    Did not see that, I will try to do a search for which connectors to clean. I assume it up by the coils? If anyone has pictures or a link to a thread, that would be greatly appreciated. Might try to clean them before my next drive!!!!

    Thanks,
    Bob
     
  5. Fiat4Fun

    Fiat4Fun Formula Junior

    Jul 1, 2008
    312
    Sunriver OR
    Full Name:
    Bob
    OK,
    Just did a search for the connections in the engine compartment for the tach. I did not see anything on the forum. I was thinking about the tach reading low, is the tach take power off both coils? So, that one coil may not be sending signal? I need to dig out my wiring diagram, but I thought I would ask in case some one knows........
    Thanks
    Bob
     
  6. Sledge4.2

    Sledge4.2 F1 Rookie

    Oct 19, 2007
    4,779
    Marin
    Full Name:
    Geno
    #6 Sledge4.2, Oct 9, 2013
    Last edited by a moderator: Sep 7, 2017
    I just had my Jalpa tach and speedo redo by Palo Alto. The tach needed to be adopted to my MSD, and the speedo needed recalibration, and both had the full on banana indicator syndrome. Palo Alto was awesome, not cheap, but awesome. He spent plenty of time discussing the work with me, which I enjoyed. Very timely turn around as well.

    Geno
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  7. Elentinos

    Elentinos Formula Junior

    Sep 8, 2011
    296
    Netherlands
    Full Name:
    Erwin
    #7 Elentinos, Oct 9, 2013
    Last edited by a moderator: Sep 7, 2017
    In my case the connector on the left side of the engine compartment under the top chassismember, just in front of the top shockmount (the wires in the center of the picture lead to it) was dirty.
    Image Unavailable, Please Login
     
  8. andyww

    andyww F1 Rookie

    Feb 7, 2011
    2,775
    London
    That connector is the source of many evils on 328s including intermittent starter motor "clicking". Well worth checking. There was a service bulletin which fitted a better seal to the connector.
     
  9. Fuzz

    Fuzz Rookie

    Nov 8, 2012
    7
    Harrisburg, PA
    Full Name:
    Farzad
    I am having tach problems also. It all started yesterday when I took my 1987 328 to have the rear main seal replaced due to a nagging leak. In short, the rear left wheel was removed, the wheel well was removed, the air tunnel to the oil cooler was removed, the oil cooler was unbolted and moved up and out of the way, then the bell housing, main shaft gear, clutch gear, etc. was removed to get to the main seal, which was replaced. I am being extremely brief here, but you get the picture. Some wires had to be moved out of the way, and in one case the coupling disconnected and later connected. When everything was put back together, the gear oil was drained and replaced, and the engine oil was drained and replaced, along with the filter (obviously). Also, all around the engine was thoroughly cleaned with brake cleaner to get all the oil off of it because during my 3 hour drive to the service center the dripping oil spread and splattered all over the place. Anyway, once all was cleaned, the car was taken for a test drive. Everything stayed dry as a bone, but the tach was reading about 1/2 of the actual rpm. It showed correct idle, but it refused to go beyond 3,000 rpm. Later as I drove toward home, it refused to go beyond 2,500 rpm, an then it pretty much stayed around 2,000 rpm no matter the speed I was going in fifth gear. Lower gears took it up to around 2,500 rpm, but I was really reving it. The car has not had tach issues, and since I don't believe in coincidences (not much anyway), I have to think something got moved around somewhere that is preventing correct signal to be sent to the tach. I haven't figured out the problem yet. I am a relatively new Ferrari owner (14 months), so I have not had much experience tinkering with them. I will try the suggestions posted already and let you know if it worked. But if anyone has any new ideas, that would be appreciated and put to test as well. Thanks in advance for any help anyone can provide. Fuzz
     
  10. Fuzz

    Fuzz Rookie

    Nov 8, 2012
    7
    Harrisburg, PA
    Full Name:
    Farzad
    Okay, so I was able to fix the tach on my 328. Basically I followed the posts about removing the instrument panel, which includes pulling out the battery light, slow down light, and the two fan lights on the instrument panel. I was unable to remove them just with finger pressure, and the dental floss idea, at least for me, did not work. I used a hooked tool and gently pulled out the light housings. As mentioned in other posts, there were screws back there that needed to be removed with magnetic philips head screwdriver. It is easy to drop the screws, so it is important to use a strong magnetic screwdriver. I was unable to remove the steering wheel because those five screws holding them in are so tight I decided to leave them alone and not risk damaging them. I now wish I had been able to remove the steering wheel because it would have made this process infinitely easier. With the steering wheel in, I had to very carefully angle the instrument panel to get to the back of the tach and remove the two screws that hold the tach tight against the back of the instrument panel. This was incredibly difficult to do because of how tight it is back there. I have medium sized hands, and I just don't see how anyone with large hands could get this accomplished without removing the steering wheel. It took me nearly an hour just to get the tips of my fingers on the screws to unscrew them. I credit the years I spent building a kit car that gave me the tenacity not to give up. Anyway, once those were unscrewed, I pulled out the tach enough to be able to pull out the wiring connectors and get out the tach in its entirety. I moved the tach to a bench, removed the three small black screws on the back of the tach, unhooked the three female connectors from the male connectors, took off the bezel, and the tach's insides just slid out. My tach is a little different than the tach posted on the Mondial post referred to earlier. Nonetheless I took a cue tip and used alcohol to clean all the contacts and moving parts. I also put one drop of 10W40 on the rear of the tach where that gold screw is on the center. That is all I did. I put everything back together, drove the car, and the tach was reading correctly again. The whole thing was easy in procedure, but incredibly difficult in execution due to the tightness of space. Good luck to anyone who tries this. Just be very patient and take your time. It can be done without removing the steering wheel, and at least in my case I did not have to send the tach to a shop to be rebuilt; it just needed a good cleaning.

    Fuzz
     

Share This Page