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Fuel System Problems w/ '98 k1500

This is a discussion on Fuel System Problems w/ '98 k1500 within the Technical / Maintenance forums, part of the General Discussion category; Hi all, I have a bit of a problem. The other day, I was driving along at about 75 when ...

  1. #1
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    Fuel System Problems w/ '98 k1500


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    Hi all,

    I have a bit of a problem. The other day, I was driving along at about 75 when the truck lurched a little. Almost immediately, the SES light came on. This was followed by another lurch, at which point the engine died. I was able to get it off the side of the road, but could not get it started. I ended up getting it towed to a shop that I have used before, and today they gave me the bad news.

    Apparently, I managed to completely fubar the fuel system. The explaination was that one of the fuel injectors had come loose, and flooded the area where the metering block and pressure regulator are held. The tech said that the fuel had then "soaked the computer" and caused it to "short out".

    Now, I have used this guy a couple of times, and I have never known him to BS me. He is an older guy though, and I think the tech descriptions of the newer car problems might confuse him. Can anyone give me a better explaination of what might have happened?

    My second question is, can I do this work myself? Here is a list of the parts that supposedly need replacing...

    1. ECM (they said that I need a new one, and I need to get it re-flashed)

    2. Metering Block

    3. FPR

    4. Fuel Injector

    5. Plenum Seal Kit (which was just replaced about 6 months ago)

    6. Metering Block Seal Kit

    Why would I have to replace the ECM? I have done quite a bit of car work, so I am confident that I could manage this.

    Lastly, the shop quoted me $2600 to fix all of this. Does it seem possible, that I could do the work my self and also make some performance or functional upgrades for the same amount of money? Does anyone have any suggestions for upgrades while I have the top of the intake apart?

    Thanks
    --Steve

    P.S. I have searched for some of this stuff, but I am a little fuzzy on the exact terminology...
    1998 K1500 Z71: 5.7L, 4l60e, 3.73
    Stock, with the exception of a K&N replacement filter

  2. #2
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    Re: Fuel System Problems w/ '98 k1500

    bump
    1998 K1500 Z71: 5.7L, 4l60e, 3.73
    Stock, with the exception of a K&N replacement filter

  3. #3
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    Re: Fuel System Problems w/ '98 k1500

    If you look in this link and scroll down to post #9, you will see a pic of the injectors, fuel pressure regulator, fuel metering block. This is better known as the Vortec injection spider. There are 2 different spiders that are pictured. The top 1 is tgeh stocker, teh sopider right below it is the GM MPFI conversion upgrade that GM reelased to replace the poorly designed stocker.

    You can get a complete new fuel pressure reguator, and 8 new injectors for under $300, some have got it for $160. Pretty much everything that will need to be replaced.

    http://www.performancetrucks.net/for...d.php?t=356743
    I really cant see that you would have to replace the PCM. I wouldthink you would have poped a PCM fuse before you you fried it, even the fuel injector spider was fully submersed in fuel.

    $2600 is WAY WAY too much for this job, I really dont think this guy knows exactly what is going on in you r truck.

    You will be able to this yourself with some simple handtools.

    here is a link with some pics and part numbers, and will help youunderstand what is inside your intake manifold. To do this you only need to remove the upper plastic intake manifold, and not the lower aluminum intake manifold.
    http://www.pacificp.com/forum/viewtopic.php?t=981
    this also has some good info

    http://www.pacific-audio.com/perform...es/231640.html



    When you turn the key to run, can you hear the fuel pump?
    WAs he able to pull any codes out of the PCM? Sounds like he couldnt connect with the PCM, so just figures it is blown???
    Check all the fuses on the dash on the drivers side and check them in the under hood fuse block.

    keep us informed

    peace
    Pauly
    Last edited by Pauly; 07-25-2006 at 10:45 PM.
    97 GMC 2wd RCSB 5.7, s10 2700 footstall, Hooker 24621hkr LT's , 2.5" cats dual 4"pipes exit B4 pass. side tire, custom driveshaft 3.42 G80 FIPK MAF descreen GM/Mercruiser Marine intake manifold 29lb LS2(EV6) injectors Ed Wright PCM(best mod), LT4 KM 14.8@94mph 2.007 4000lbs 122mph

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    Re: Fuel System Problems w/ '98 k1500

    I would definately get a second opinion. I don't see how the fuel injection that is under the plenum could soak the ecm.

  5. #5
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    Re: Fuel System Problems w/ '98 k1500

    in reply to pauly...

    Thanks for the info and the advise. I was thinking that the ECM thing seemed fishy. I checked all of the fuses visualy on the side of the road the other day, and they looked fine. I will check them with a meter when I get the truck to my place. The truck cranks fine, and the fuel pump makes its normal sounds...kind of a high pitched whine. When I left the truck on Saturday, I could key it on, and everything seemed to work with the exception of actually starting.

    It does seem a little odd that the whole thing would just quit...unless the fuel caused the metering block to go bad. I would have expected the bad cylinder(s) to throw a code though.

    Anyway, I am going to get the truck back and pull apart the upper intake. I have thinking about a vmax spacer and a wait4me tune for a little bit. Maybe this is the time to try it all out. At the very least I would have a "new" ECM if my current one is indeed toast.

    --Steve
    1998 K1500 Z71: 5.7L, 4l60e, 3.73
    Stock, with the exception of a K&N replacement filter

  6. #6
    technut
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    Re: Fuel System Problems w/ '98 k1500

    late model vortecs depend on high pressure to make the system
    function correctly. 98 should be 55-62psi, can start and run
    @ 52psi, anything less... usually will faulter and mostly wont
    start.
    fuel pressure check key on engine off will cut the "bill" down
    a lot. hes getting into that wallet...
    guessing with your money is how id put it.

    airdeano
    2001 Silverado 4.8L 4-spd Automatic 3.42
    ? horsepower
    ? torque
    will find out soon!

    1965 C10 5.3L (SSR) TH4L60e
    (It's Alive! 07/04 It Drives! 03/05 Daily Driver XX/08!)

  7. #7
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    Re: Fuel System Problems w/ '98 k1500 - Update

    I got the truck towed home on Friday, and got it mostly apart yesterday. Several observations...first, its probably been said before, but that whole injection system is terrible. I hope that someone at GM was fired over that...not likely though. Second, everything has come apart pretty easy...I haven't had to fight anything. Last, EGR has to be the worst idea that anyone has ever come up with. It amazes me that the engine would even run with so much built up crap in the intake and runners.

    The one major point of contention I had with the shop was the exact condition of the computer. I removed it, and before I took it to a dealer to have them look at it, I took the main cover off. There are several little integrated chips on the circuit board and they were all disconnected...a couple were actually floating around inside. I cannot imagine how this happened, but my ECM is completely toast.

    So, I need to get a new one. The dealer will sell me one for about $340 plus $125 for the reprogramming. I was wondering though...if I can get a used one from a junk yard, could I get an aftermarket company (wait4me, westers, pcm4less, etc) to program it with the stock program. Or could I just call one of those companies and buy the whole thing from them? Any thoughts?

    Lastly, can someone confirm some part numbers for me. GM part # 93441235 is the "upgraded" fuel injection "spider" which includes the 8 injectors, the fpr, and the metering block? GM part # 93442096 is the bracket for this "spider", and GM part # 17113206 is the seal kit? Do I need any other parts or seals?

    --Steve
    1998 K1500 Z71: 5.7L, 4l60e, 3.73
    Stock, with the exception of a K&N replacement filter

 

 

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