1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

Question for B&B

Discussion in 'Ford Trucks' started by f250man, Dec 13, 2008.

  1. f250man

    f250man PlowSite Veteran
    Messages: 3,124

    I have a 99 with a 5.4 L and it has 3 misfire codes and I just changed the plugs and when I give it gas real hard it smooths right out and runs fine but the at normal road speed So I was wondering if it was a bad coils or if it is injectors. Thanks Steve
     
  2. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,526

    Are the misfire codes all on the same bank?
     
  3. Dissociative

    Dissociative 2000 Club Member
    Messages: 2,066

    my money says coils...prolly 2 bad and 1 maginal...

    do all 8 and save money and time
     
  4. Spitz

    Spitz Senior Member
    Messages: 192

    You changed the plugs but didnt bother putting on new plug boots?? Usually if you pinch them you can see the cracks in the very ends and can cause slight misfires on startup and any other time ignition load is high. Anyway, I would suggest taking it to a shop because anything said here will be speculation. Ignition misfires are usually caused in high load conditions, when the engine is running leaner, such as going uphill in overdrive will usually cause misfires to appear.
     
  5. f250man

    f250man PlowSite Veteran
    Messages: 3,124

    Well its not the coils because when I changed them to other spark plugs it still had the misfire on 4-5-6- and I switched the injectors around and still have a misfire in the cylinders.
     
  6. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,526

    Sounds more like a lean misfire more then an ignition misfire. I doubt ur gona have a ignition misfire on 3 cylinders. I might be looking for a vacume leak. Do u have a scanner with live data. Can u tell me ur long tern and short term fuel trim numbers. Can u feel the skip at idle?
     
    Last edited: Dec 13, 2008
  7. carl b

    carl b PlowSite.com Addict
    from Ohio
    Messages: 1,330


    if you still have the old plugs
    what color are the they ? if their white its running lean.. if their gummy to rich.. so if its a coil you should have a "gummy plug "

    just chimimg in here so if you already looked sorry
     
  8. hydro_37

    hydro_37 PlowSite Veteran
    from iowa
    Messages: 3,790

    Why did my post get deleted????
    I would change the plug boots and use di-electric grease on them.
     
  9. tim096

    tim096 Senior Member
    from wny
    Messages: 100

    Iwoud ck the fuel psi. Might be low, If the truck has been missing for a while you might have a pugged converter. try pulling out the 02 sensor and see how it runs, As for vacuum leaks the pcv elbow is very common it is located behind the air intake on the bottom of the air pl. sort of a pain to get to, but a very common air leak. hope this helps
    Tim
     
  10. Spitz

    Spitz Senior Member
    Messages: 192

    Yea i was thinking about vacuum leaks as well when he said it runs fine at WOT, when manifold vacuum is really low, will obviously be higher on cruise and at an idle, where from what i deciphered is when its running worse?? Could be a number of things, my suggestion, take it to a shop.. MY question is how are you getting the truck to set misfire codes readily?? Every one we get is a ******* to get any misfire info out of (no counters) Only thing we really rely on is MODE 6 or thank the lord if it actually does throw a code ( if the cust has driven it around misfiring for a few days). Fords misfire detection sucks to say the least, maybe the factory scan tool gives misfire data but we dont have access to that yet as we DO NOT LIKE FORD.. :)
     
  11. tim096

    tim096 Senior Member
    from wny
    Messages: 100

    Spitz, get an ids and you will love fords, The factory scan tool is the only way to go. I can ck fuel psi,injectors, compression. and missfire in less than 10min with it.
     
  12. Spitz

    Spitz Senior Member
    Messages: 192

    Im sure we will get one eventually, truth be told most the vehicle we service end up being gm's. So we bought a tech 2 instead.. I just hate fords diagnostic routines, the older vehicles just suck to work on, thank god for obd2! Heres kind of a funny story, in tech school we were tested on diagnostic routines, the big 3, ford, gm and chrysler. Each of my classmates all passed easily gm and chrysler (they are very similar). We got to the ford BOOKS, which were about 8 inches thick (no ****) had NO page numbers and made no sense.. Not one person passed this ford test.. Teacher couldnt believe it..
     
  13. f250man

    f250man PlowSite Veteran
    Messages: 3,124

    Every plug was a white color and it is not throwing a code right now. No check engine light so Im still assuming that it is cylinders 4-5-6 having a miss fire. I was told it wouldnt be a o2 sensor and you only hear the miss in the end of the exhaust pipe not at the engine.
     
  14. Spitz

    Spitz Senior Member
    Messages: 192

    Ahh, so your assuming its the same cylinders.. Not good. Never assume. I really would have changed the plug boots right away, they do cause problems and i've fixed quite a few by simply replacing them.. Not to say its your problem, but its not ruled out. Kind of uncommon to see three cylidners misfire though and it be an ignition miss. Those cylinders arent all on the same bank either.. I'll say if you cant get codes easily or be certain its the same cylinders or not, its shop time. Get it to a shop before you do damage to catalytic converters..



    ps- Go and brake torque your engine and see if the misfire is happening when you do this.. This will put a load on the ignition system and usually problems put up while doing this, not always, but more then not.
     
  15. f250man

    f250man PlowSite Veteran
    Messages: 3,124

    Any time I stomp on it it runs like a top and when I brake checked it it ran smooth no brake up. Im starting to get pissed I 've done everything that I or anyone else said to check and it still dose it. Im thinking about bypassing my cat and see what it dose,
     
  16. Spitz

    Spitz Senior Member
    Messages: 192

    Dont bother, take it to a shop that knows what to do. We can only offer a limited scope of what to check, without seeing the truck running and hearing it, its hard to determine anything. It may take a train tech a small drive around the block to understand whats going on, and with a good scanner could yeild a lot more info than what we are working with..
     
  17. RichG53

    RichG53 PlowSite.com Addict
    Messages: 1,135

    .. So many back yard mechanics... but take it to a shop...just shut up.......
     
  18. f250man

    f250man PlowSite Veteran
    Messages: 3,124

    My brother and his buddy are ford techs and have no idea whats wrong with it. and if you have nothing to offer why dont you just shut up. Thanks
     
  19. carl b

    carl b PlowSite.com Addict
    from Ohio
    Messages: 1,330

    not everyone just throws money at every problem . plus its fun to have te joy of fixing it your self
    sorry Steve I jacked your thread
     
  20. f250man

    f250man PlowSite Veteran
    Messages: 3,124

    Well guys I fixed it myself replaced all the coil boots and one coil and now she runs like a raped ape. Not really only got the 5.4 . :D :D