So, this just happened. Damned electricals... | Page 7 | FerrariChat

So, this just happened. Damned electricals...

Discussion in '308/328' started by thorn, Sep 21, 2020.

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

Page 7 of 8
  1. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    #151 thorn, Nov 30, 2020
    As it turns out, I didn't have time - or more accurately, TAKE the take (hah) - to heat gun the sensor. Impatience and fears of holiday shipping times got the best of me, and I went ahead and ordered/installed a new mag sensor. It seems to have a later Lot Number than the old sensor, according to the part # stamp on it. I routed the cable around the back of the engine bay, instead of under the plenum where the old one was. Hoping this will help cull potential heat and crosstalk possibilities, as the cable will now never cross a secondary voltage line.

    Took about a 20 minute drive around town on Thanksgiving, and had no hiccups. Parked the car for a half-hour, then took another 20 minute drive. Operating temps got to to where I've normally had a failure, yet no failure occurred. Girlfriend asked if I'd solved the problem, but I'm still too gun-shy to declare it fixed. Have thought that before, several times the past 2 months. ;)

    Yesterday, another decently long drive around town including a stop at the store. Even with the car in traffic closing in on 90C temp, it never faltered. In all cases, the cold idle is never even twitching at startup - it's as if the engine knows where it wants to be, and it's not searching in that 1300-1500 range for a sweet spot. Hot idle remains very steady as well.

    I haven't taken it up to highway speeds yet, as I really didn't want to deal with a holiday weekend and hoping to find a tow if I needed one. So not calling it "fixed" yet, but so far it's been promising.

    On a slightly unrelated note: ever since I replaced the fuel pump, the gauge bounces around a bit as if it can't decide how much fuel is in the tanks. I'll leave that fix for another season, as I know how much is in the car. Probably needs a new sender; perhaps the better fuel pump is creating a situation that the old sender is too reactive to.
     
    Saabguy, JL350 and TurtleFarmer like this.
  2. smg2

    smg2 F1 World Champ
    Sponsor

    Apr 1, 2004
    15,521
    Dumpster Fire #31
    Full Name:
    SMG
    #152 smg2, Nov 30, 2020
    Sounds like it was a bad or dying sensor.

    Knock on wood for yah..
     
    thorn likes this.
  3. smg2

    smg2 F1 World Champ
    Sponsor

    Apr 1, 2004
    15,521
    Dumpster Fire #31
    Full Name:
    SMG
    #153 smg2, Nov 30, 2020
    My apologies for pushing the hall sensor, didn't think it would have been an issue for the XDi to run. Ever hear back from them on it? At least the new one is working.

    Check the ground wire at the top of the tank, tiny little m8 nut holding down a ring terminal for ground. Spades for the sensor. I'd suggest a quick de oxidize clean.
     
  4. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    #154 thorn, Nov 30, 2020
    Last edited: Nov 30, 2020
    Dude, no worries at all on that. I thought it was a great suggestion, and I'd honestly prefer to be able to use that sensor. But not going to sweat over a $25 sensor and some shrink wrap. ;)

    And FWIW - if it does turn out to be the mag sensor, I'm seriously considering buying a spare and keeping it in the car with the spare oil, fuses, and coolant.

    Nope, not a word.

    Sweet. Sounds like an easy task. That fastener point was (bizarrely) the former ground for the coils a couple years ago, if you can believe it. I'll be buttoning up some things tomorrow and will add that to the list.
     
  5. smg2

    smg2 F1 World Champ
    Sponsor

    Apr 1, 2004
    15,521
    Dumpster Fire #31
    Full Name:
    SMG
    #155 smg2, Nov 30, 2020
    Grounds are one of the more problematic issues with the 308 series. I always replace the ground strap with a new one, plated copper not aluminum. Summit racing.

    The engine sits in the bay on isolation dampers not mounts, and the reaction rod is also isolated.. so the only true ground path is the strap on the passenger side, frame rail to gearbox.

    On the race engine builds I also have a couple other ground straps added. Doesn't hurt.
     
    greg328 and thorn like this.
  6. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    6,691
    Full Name:
    Mike 996
    #156 mike996, Dec 2, 2020
    I think you should have done the hair dryer test first. It would have proven (either way) whether the mag sensor had a temp problem. NOW, you are still wondering IF the new sensor fixed the problem or if the problem will recur. ;)
     
  7. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    #157 thorn, Dec 2, 2020
    Agreed on that, I knew that would be a big diag pitfall.
     
  8. GordonC

    GordonC F1 Rookie
    Owner Rossa Subscribed

    Aug 28, 2005
    4,121
    Calgary, AB, Canada
    Full Name:
    Gordon
    #158 GordonC, Dec 2, 2020
    Last edited: Dec 2, 2020
    Back when Scott first mentioned his preference for the hall sensors, I started reading about it and decided to order one to install with the rest of the XDI system (this week or next week). The hall sensor arrived from Electromotive today, with an EXTREMELY handy instruction sheet - doesn't exist on their public support pages, but it answers all your questions:

    Image Unavailable, Please Login

    So, to use a hall sensor you require an XDI with serial number -3371 or greater; and you need to add a wire jumper between pins 4 and 5 to enable the XDI to use the hall sensor. They caution that with that jumper the XDI won't work with the mag sensor, but it would be easy enough to put a switch or just a connector on that jumper wire - open for mag sensor, close for hall sensor.

    The XDI system I bought from Nick just over 2 years ago is Rev D # -4384, well beyond the -3371 required, so it would seem that the hall sensor compatible XDI has been sold for well over that 2 years.

    Cheers,
    Gordon

    Oh, I also bought a MAP sensor to be installed - after reading the manual for entries related to it, I can't see why the XDI system wouldn't include that already in the Nicks kit. Vacuum advance setups (or higher MAP pressure adjustments) are nothing new, part of old distributor systems and most fuel injection systems, including the original 308 Digiplexes. The QV already has a vacuum line (for the Digiplexes) going back to the trunk, so it should be very easy to incorporate in the XDI setup.

    My thinking is I'd want it set up so that the ignition curve at light throttle is 5* - 8* more advanced than the full throttle ignition curve that is the default XDI settings, then the MAP sensor can pull up to (5* - 8*) at large throttle openings (higher MAP). Should give better cruise fuel efficiency and snappier part throttle response than the XDI with no MAP sensor. That advance range (5* - 8*) difference between light throttle and full throttle is similar to what the Digiplex timing map range is.
     
    TurtleFarmer, JL350 and thorn like this.
  9. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    #159 thorn, Dec 3, 2020
    Well, look at that... there's the missing link of the mystery. I might just pull the (new) mag sensor out, reinstall the Hall + jumper, and see what happens.

    Thanks for sharing that, Gordon!
     
    GordonC and TurtleFarmer like this.
  10. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    #160 thorn, Dec 5, 2020
    Final reassembly day, I think.

    Drove the car to work, with the new Mag sensor installed. Made the 20 min trip just fine, no issues. Car running great. Got the car on the lift, replaced a barely-fraying alternator belt. The banjo on the new fuel pump had just the barest, slightest drop of wetness... maybe 1cc of gasoline? I tightened the bolt a bit more. Don't want to strip the thing, of course.

    Checked the serial # on my XDI ... and wouldn't you know it, it's under the minimum # to use a Hall sensor. Apparently I could send the unit to Electromotive for some mod, but I'm not going to bother with it for now. The car also made it home fine, so I'm almost ready to declare it's been resolved. Still want some higher-speed interstate runs to feel perfectly confident, but with 4 good drives since the new Mag sensor and no issues - pretty sure that was the last misbehaving component.

    Until the next demon arises, I suppose. ;)

    Also: a quick but heartfelt thanks to everyone who contributed in the thread, offered advice, expressed sympathy, and wrote very long detailed (and helpful) posts to help pull the 308 out of this morass. I really, really appreciate it.
     
    Dane, derekw, GordonC and 4 others like this.
  11. kiwiokie

    kiwiokie Formula 3

    Aug 19, 2013
    1,464
    Tulsa, OK
    Full Name:
    John McDermott
    #161 kiwiokie, Dec 5, 2020
    Woohoo!


    Sent from my iPad using FerrariChat
     
  12. derekw

    derekw Formula 3
    Silver Subscribed

    Sep 7, 2010
    1,520
    London, UK
    Full Name:
    Derek W
    #162 derekw, Dec 5, 2020
    ... and the winner is... drum roll... Richard Lloyd in post #14 "I'm not familiar with the XDI ignition system, but the symptoms described sound more like an ignition module /crank sensor failing."

    Glad it's sorted :)
     
    thorn, GordonC and rjlloyd like this.
  13. Brian Harper

    Brian Harper F1 Rookie
    Owner Silver Subscribed

    Feb 17, 2006
    4,078
    San Jose area
    Full Name:
    Brian Harper
    #163 Brian Harper, Dec 6, 2020
    He nailed it!
    The video was clear evidence for me it wasn't fuel related.
     
  14. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    6,691
    Full Name:
    Mike 996
    #164 mike996, Dec 6, 2020
    I said the opposite - that the video CHANGED my opinion from it being ignition to it being fuel! ;) Apparently I got the diagnosis wrong! Well, I guess that had to happen once in my life! :)

    Or, should I say, at least once this week!:rolleyes:
     
  15. derekw

    derekw Formula 3
    Silver Subscribed

    Sep 7, 2010
    1,520
    London, UK
    Full Name:
    Derek W
    #165 derekw, Dec 7, 2020
    "Or, should I say, at least once this week!" only once?... clearly not married
     
  16. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    #166 thorn, Dec 7, 2020
    While it ultimately wasn't fuel, as it turned out there were a couple of fuel-related components that were suspect for good reason. The filter was of "who knows what age", and the pump itself was "why the heck is THIS pump here?"

    Have been thinking about my initial plan, one I stopped whining and decided to approach it without so much angst: Start with how the system should be wired (and/or what components are present), and determine if it's properly done. Then move on to component troubleshooting.

    All in all, I think it mostly went that way... including suggestions to look at the fuel situation. Perhaps the pump and filter weren't ultimately THE problem, but were A problem - so, I'm glad to have gotten those sorted out as well. Beyond just the mag sensor, there were some terminals to the XDI that I cut and re-crimped myself because the existing looked a bit suspect. So - examine everything, trust nothing, and make sure it's installed and performing how it should be.
     
    Dane and Jdubbya like this.
  17. Saabguy

    Saabguy Formula 3
    Silver Subscribed

    Mar 28, 2012
    1,759
    Shreveport, LA
    #167 Saabguy, Dec 8, 2020
    As we say in the South, bite your tongue! Don't touch a damn thing! ;-)

    Congrats on the fix!

    Lester

     
  18. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    #168 thorn, Mar 6, 2021
    And so.... it wasn't the mag/crank sensor.

    Took the car for a trip to the beach last weekend.... within about 20 miles towards our destination - here we go again. Death in power. Towed the car home.

    Pulling the XDI PCM and coils; going to send back to Electromotive for diag and testing.
     
  19. TurtleFarmer

    TurtleFarmer Karting
    Silver Subscribed

    Jan 13, 2020
    215
    Full Name:
    Jason S
    #169 TurtleFarmer, Mar 6, 2021
    Aaaaugh. So sorry. After so much time spent on it, sending it back to Electromotive sounds like a great next step....
     
  20. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    #170 thorn, Mar 6, 2021
    It's really sort of a Hail-Mary, at this point. Even if it passes diag, I'm probably going to inquire as to trading it in on a unit that will work with a Hall sensor. Hate just using the parts cannon, but... that's the best next step I can think of. I've replaced newer Honda PCMs with barely more evidence, and so far no come-backs on those. ;)
     
  21. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    6,691
    Full Name:
    Mike 996
    #171 mike996, Mar 6, 2021
    I know you probably don't want to hear this but wouldn't it just be easier/less mental strain to return the ignition system to the OEM configuration? Certainly easier to diagnose/repair problems... ;)
     
  22. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    #172 thorn, Mar 6, 2021
    Last edited: Mar 6, 2021
    Probably. But I'm guessing buying all the components would cost me around $3-4K. I don't have the original distributors, digiplex, etc. (The car is configured as I bought it; those components were removed by the previous owner.)
     
  23. kiwiokie

    kiwiokie Formula 3

    Aug 19, 2013
    1,464
    Tulsa, OK
    Full Name:
    John McDermott
    #173 kiwiokie, Mar 6, 2021
    That sucks. Sorry to hear the ignition troubles are not over.


    Sent from my iPhone using FerrariChat
     
  24. GordonC

    GordonC F1 Rookie
    Owner Rossa Subscribed

    Aug 28, 2005
    4,121
    Calgary, AB, Canada
    Full Name:
    Gordon
    #174 GordonC, Mar 6, 2021
    Last edited: Mar 7, 2021
    Sorry to hear!

    FWIW, I did get my new XDI installed in December, using the Hall sensor and a MAP sensor. I only got one very brief test drive before more snow fell, but I confirmed my over-5600 rpm misfire is gone and the engine seems much more responsive. I will do some mapping of the ignition advance once the snow (and salt) are off the roads here.

    Regarding switching back to stock - you're right, it would be extremely expensive, the Digiplex boxes aren't available new, and the rebuilt units are priced at ~$1600 each! I'm not a fan, aside from any of the original Digiplex boxes are getting pretty tired now (age, if not miles), the distributor setups aren't great with unavailable OEM parts and aftermarket replacement parts of poor quality; plug extenders are the same story; just too many points of failure.

    My XDI installation is 100% reversible, there were only two extra holes drilled anywhere, those being on the rear timing belt cover to mount the Mag/Hall sensor (and I bought a used spare timing belt cover, so I have the original 'undrilled' belt cover on the shelf):
    Image Unavailable, Please Login
    Image Unavailable, Please Login

    XDI and accessories on mounting plate for trunk:
    Image Unavailable, Please Login

    Wired up - looks a bit of a mess, but looms were laid out to fit properly in the under-floor space when the mounting plate gets turned over - modern WeatherPak connectors, disconnects on all looms:
    Image Unavailable, Please Login

    Tucked away:
    Image Unavailable, Please Login

    Electromotive Coil units mounted on the stock coil bracket mount points - I 3D-printed a mounting bracket in polycarbonate to orient the coil packs vertically beside each other, hanging from the factory coil bracket mounts. I also ran another ground wire from a bolt beside the starter mount to the coil packs, and back to the XDI bracket:
    Image Unavailable, Please Login
    Image Unavailable, Please Login

    New plug wires with no extenders:
    Image Unavailable, Please Login

    No more distributors! Nick sells these 3D-printed cam end caps which fit over the distributor drive stub on the end of the camshaft:
    Image Unavailable, Please Login

    Plug wires made with Taylor wires and Hemi tubes, re-used original plug well boots - original extender assembly vs new Taylor Hemi isolator parts:
    Image Unavailable, Please Login

    The plug wire runs from the coil through the boot directly to the top of the spark plug - Taylor plug boot assembly in progress:
    Image Unavailable, Please Login

    Final assembly as it sits on the plugs:
    Image Unavailable, Please Login

    Hope this might help when you get the replacement XDI back.

    Cheers,
    Gordon
     
    RodC328gts, thorn and Milkshaker0007 like this.
  25. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    6,691
    Full Name:
    Mike 996
    #175 mike996, Mar 7, 2021
    Gordon, your setup looks very nice but it sounds like you did a lot of work on your own to get it that way - making brackets, wiring, etc.

    How much of what is in your pics is included in the XDI system vs what you did on your own (coil brackets, etc)? I ask because I suspect that most folks purchasing an XDI ignition (and I know absolutely nothing about them other than the name) would expect to simply remove the old parts/install the new parts, and have qreat-running engine. But from comments on this site, it doesn't appear that way to me. It seems as though there is some difficulty in sorting out these systems though maybe I'm basing it on the typical internet thing whereby we complain often and loudly when something works badly but don't say anything at all when it works well! :)

    I guess my basic question would be: How long was it from the time you started installation to the time the car was running perfectly? Of course, the time involved may be of no issue to someone who has the car "laid up" for some extended period anyway. I'm thinking more in terms of someone who wants to install an XDI over the weekend and drive 500 miles on Monday. Based on Thorn's current experience, I wouldn't consider an XDI at all but obviously you have had a different, and hopefully more common, experience.
     
Page 7 of 8

Share This Page