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Removing 308QV fuel injectors...

Discussion in 'Technical Q&A' started by johnk..., Jun 12, 2004.

  1. johnk...

    johnk... F1 Veteran
    Owner

    Jun 11, 2004
    8,093
    New England/FL
    Hi,

    I'm new to this group, but not to Ferrari. I have owned my '85 GTB QV since new. I have a simple question. I have a bad injector that I want to replace (yes it's definitely the injector). I have the new injector, and a new seal, but for the life of me I can't figure how the old part comes out.

    I have removed the snap ring. Below that there seems to be a retainer of some type over the seal. I would have expected the injector/seal/retainer to just pull out after removing the snap ring. But it doesn't seem to want to budge. I probably just need to pull harder but before I do something regrettable I though I'd ask.

    Any help would be appreciated.
     
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  3. mondial86

    mondial86 Formula Junior

    Nov 1, 2003
    298
    MA
    Full Name:
    David Holmes
    When I did my 86 they just poped out using a screwdriver pull and pry a bit they will come out ,I did not remove the c clip ,i did not replace the o rings.to put back I put a nut on the top (to keep s..t out)then put on a socket and an extention and taped then in with a rubber hammer
    DAVID
     
  4. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    17,062
    USA
    Full Name:
    Hugh G. Rection
    Would highly recommend you replace them all, especially if they are the original steel ones. The newer brass ones are supposedly much better quality. I recently had them replaced in my 87 328 GTS, as I had a couple that were leaking on shut down, contributing to a hot start problem. My mechanic further tested the old ones after replacing, and noted that two of them had very poor spray patterns as well...almost like a stream. Gary Reed on this list is having them replaced on his 83 512BBi for similar problems, as we speak.

    The correct ones for most 80's vintage Ferraris is Bosch part number 0437 502 047 Go to the Bosch USA website to double check the part number, please. Also, you can buy the injectors and o-rings on line at :http://www.importeccatalog.com/ Unfortunately the recently raised the price from $21.15 to $29.99. Still a great price though. The o-ring is the same as for a 78 Rabbit, so run that through their system and it will come up.

    Regards,
    Dave
     
  5. michaelthuber

    michaelthuber Karting

    Mar 4, 2003
    150
    Cincinnati, Ohio, US
    Full Name:
    Michael Huber
    I am glad this thread showed up now. I have a box of 8 new injectors that I want to install in my 85 Mondial 308QV cab. I bought the same injectors and 78 Rabbit seals that Dave mentioned in his response. My first question is: Can I get the injectors out without removing the circlips? and the second question is; do I have to remove the plenum to get to the ones in the front bank. Any responses would be greatly appreciated.
    Mike
     
  6. abarthracer

    abarthracer Formula Junior

    Dec 6, 2003
    373
    Falmouth, Cape Cod
    Full Name:
    david S.
    Mike,
    I just did a couple on my Mondial, and even though David is a good freind(!) I respectfully disagree with his suggestion to not remove the circlips or O rings. First I would blow the area around the injector out with air, then spray with WD40 to help ejection. Remove the circlips and orings. The reason I say to remove is you have the potential to rip or tear an O ring when pulling them out or putting in, especially if they are old and hardened. It is a very easy operation. It may take some effort to get them out, but they do just pull out. The Orings are very inexpensive and actually came with my injectors. Good luck
    David S.
     
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  8. johnk...

    johnk... F1 Veteran
    Owner

    Jun 11, 2004
    8,093
    New England/FL
    Well, you're not going to get the seals out without removing the spring clips. Here is the structure as depicted in the factory workshop manual. The injector is surrounded by the seal. There is a bushing (aluminum?) that fits over the seal. The bushing looks like a short tube open at on end and with a 1/2" hole in the other. The seal fits into it snuggly. The fuel line end of the injector protrudes out of the hole in the bushing. This entire assembly appears to slide into the manifold and the spring clip keeps it from popping out and keeps the seal compressed against the manifold to make the seal.

    My original question concerned how to remove this assembly. I'm sure you could manage to pull the injector out through the seal w/o removing the clip and force a new injector down through the old seal but I'm certainly not about to do that. The last thing I want is a 20 year old seal, damaged and leaking, after I make the repair.

    What I really want to know is if there is a specific "correct” procedure for removing the entire assembly, injector, seal and bushing so a new seal and injector can be inserted. I think the real problem is that after 20 years the original seal is sort of bonded to the manifold and will probably take some effort to remove. I brought this topic up because not having done this before I though I might get some sound advice here.

    By the way, while I at it I notice the timing belt replacement intervals is a hot topic around here. The Factory manual for 84 and 85 308 QVs say inspect at 12K miles, replace at 25K. Nothing about time intervals.
     
  9. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    17,062
    USA
    Full Name:
    Hugh G. Rection
    You can spend days reading threads on timing belts...so we won't go there...;)

    Do replace all you injectors. If you have the original steel ones, and you have a bad one, the others aren't far behind....
     
  10. michaelthuber

    michaelthuber Karting

    Mar 4, 2003
    150
    Cincinnati, Ohio, US
    Full Name:
    Michael Huber
    I'll bet if you have a Mondial Cab you didn't replace a couple on the front bank. I can't even see the injectors in the front bank when I remove the access panel behind the back seat, much less get in there with circlip pliers to get them out. I was hoping there was an easier way to get to the front bank than removing the air plenum. Looks like I would need to remove the plenum to get to cyls 2&3 on the rear bank too. Is there a trick that someone knows?
    Johnk, sorry I am not trying to hijack your thread, just have a similar need.
    Mike
     
  11. johnk...

    johnk... F1 Veteran
    Owner

    Jun 11, 2004
    8,093
    New England/FL
    No wonder I was confused. I should have known better than to use the factory workshop manual as a guide. I figured one way or the other the injectors had to pull out. So I I made a little tool the screwed over the injector and allowed me to pull it out. I was just as mondial86 indicated. The injector pulled out and had an O ring around the body. I used the same tool with a lever to press the injectors back in. (Sorry mondial86, using a rubber mallet just didn't sound right to me.) Anyway, the seal I purchaced with the injector, while matching the factory manual, doesn't appear anything like what is actually in the engine. Perhaps it's from a later model 328? It's more like a ruber compression fitting.
     
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  13. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    17,062
    USA
    Full Name:
    Hugh G. Rection
    308's/Mondials and 328's all use the same injectors and o-ring seals.
     
  14. RGigante

    RGigante F1 Rookie
    Project Master Owner

    Nov 1, 2006
    2,872
    Portugal
    #11 RGigante, Jan 15, 2007
    Last edited by a moderator: Sep 7, 2017
    I've just replaced the injectors in my 328. The tool I've made has helped a LOT !

    Take a look at the picture at
    http://www.ferrarichat.com/forum/showthread.php?t=132818
    (bottom of page)

    You don't have to remove the plenum, just the throttle assembly.
    If you really need/want to remove the plenum, please be very careful with the spacers!
    I've done the following:

    - unscrew all eight nuts but leave them in place (about 5mm down)
    - make sure the rubber seals stay down, together with the spacers. Easy to do with a flashlight and a small screwdriver
    - insert rectangular pieces of hard card box paper between the rubber and the plenum. This is to make sure the air intakes are covered by them
    - make sure the paper comes out the other side
    - remove the screws
    - remove the plenum carefully.
    - immediately cover those air intakes with paper or towels. I've used a few newspaper pages

    A couple of pictures attached should make it clear. Now I can replace both water hoses under the plenum and clean everything !
    I strongly recommend following this procedure if you're considering removing the plenum someday. It's safe !!

    Rui
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  15. spiderseeker

    spiderseeker Formula 3

    Jul 22, 2005
    1,708
    Colorado
    Full Name:
    Steve
    Rui: Excellent job, great explanation and photos !!!
    Thanks,
    Steve
     
  16. mg54

    mg54 Rookie

    Jan 12, 2005
    48
    I just replaced one on my mondial qv...I disonnected the fuel line, yanked it out carefully, slid a new rubber "o" ring on it and pressed it in with a piece of wood and a rubber mallet.

    I did the one under the throttle linkage and did not have to remove anything..

    Good Luck

    Mike
     
  17. bergxu

    bergxu Formula 3

    Aug 16, 2005
    1,302
    OnTheSerpentMound
    Full Name:
    Aaron
    The reason you want to replace injectors as a set is because the new ones are of a different opening pressure than the old steel ones were. I go through this with Mercedes customers all the time who hem and haw about having to replace a full set of 8 nozzles for one bad one.
     
  18. RGigante

    RGigante F1 Rookie
    Project Master Owner

    Nov 1, 2006
    2,872
    Portugal
    Very good point. And besides diferent fuel pressures, when you have 18 year old steel injectors like mine, if one is bad the others won't be far behind.
    But then again I always replace light bulbs in pairs when one fails :)

    One other point that I've found yesterday: I thought I had a bad warm up regulator, but all I have is badly corroded contacts on the WUR connector. A good cleaning and it's working !

    Rui
     

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