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Thread: Lift Pump?

  1. #1
    Join Date
    Jan 2007
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    Belleville,Il
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    Default Lift Pump?

    I posted on this awhile ago.Ive got an 03 that just had the injectors replaced last Jan. a little while after that i got an AEM BruteForce intake,after that a Diablo Predator.At first i took it easy on the programs,first the 65,ran pretty well,then the 85,even better.Then my power addiction got ahold of my better jugdment,and i put it on 120 and the thing was screaming.I drove around for a while on the 120 taking it very easy,only getting on it maybe once a week.Ever since then the thing hasnt run nearly as well,sometimes it runs better than other times,still nowhere near the first time.Its running extremely erradic,sometimes lots of smoke sometimes none at all.Im begining to wonder if my fuel pump isnt keeping up with my fuel demands?Could there be a ghost in my ECM?Im very close to trading this truck in,because of my lack of knowledge on diesels.Any help at all would be GREATLY appreciated.
    NoSmoke

  2. #2
    Join Date
    Nov 2000
    Location
    foxboro,ma.
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    908

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    My feeling is that if your looking for power then at any power levels over 60 hp more then stock one lift pump is fine , more then 100 hp you should have two pumps . dont know much about your power adder so sorry cant help much there. I can say that fuel and the type of air you in makes a differance , cool slightly damp air will make it rip.... hot air will smoke some.
    93 c-2500 6.5td,96 6.5td x cab,01 GMC lb7 Xcab ,2004 lly crew cab ,2006 lbz crew cab,honda CBR1100xx,2003 polaris prox 700 , 2001 31' holiday rambler 10K lbs house on wheels!

  3. #3
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    Jan 2007
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    Belleville,Il
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    Default

    Thanks Mark,for your input.This is frustrating as hell,im wondering if ive weakend my fuel pump somehow.Something is definatly not right,its not running half of what it did when i first put the 120 tune in it.It feels like its being restricted somehow.Thanks again.
    NoSmoke

  4. #4
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    Apr 2001
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    CA
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    Arrow

    The PCM and TCM has caught on to your new found power, and is defueling to accomodate the also new found tranny and torque converter slippage. If you are running the 120 on an OEM tranny, it will do this....until it can't. Either upgrade your tranny, or rebuild it (sooner or later), or stay off the 120 setting. If you insist on getting your power back, put it back at the factory setting for a while, and start over. You'll be able to do this about a half dozen times before your tranny grenades.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

  5. #5
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    Jan 2007
    Location
    Belleville,Il
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    Default

    Thanks Mav,that makes absolutley perfect sense,i never thought of that,but thats exactly what i wanted to hear.What do you think on the tranny,converter and clutches?Thank you VERY much.I was just thinking that ive never limped it,no codes is that still possible?Thanks again.
    Last edited by nbloecher@yahoo.com; 09-16-2007 at 20:06. Reason: Im stupid
    NoSmoke

  6. #6
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    Arrow

    If you've only "played around" a little, you are probably only seeing the first signs. You may dodge that bullet and have not hurt the tranny too much. More often than not, you can go back to where you were before without a loss. The problem most folks have is understanding that first warning. If a tranny upgrade isn't in your future, I suggest doing a complete tranny service (fluid and filter) and tone it down. Refrain from using the higher power levels in higher gears. The torque converter won't hold 85+ HP in OD, and 120 won't hold in direct. The more you use the high power levels, the worse it will get, until you can't get across the street at factory power.

    Do you have gages? If not, you'd be amazed at what you would have seen on the EGT at that power level. Scary. A good 4" exhaust system helps. In any case, get gages if you are going to play.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

  7. #7
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    Jan 2007
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    Belleville,Il
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    Default

    Ive been fairly kind to the tranny(no boosted launches and no hammering 4th-6th)its been different since that first 120 tune,on all tunes.The first time on the 85 it would squall the tires from 10mph-20mph,now the tunes feel to be 50% of what they were originally,thats what led me to believe it was a fueling problem.On the tranny,ive seen JK say around $3500 for a heavier duty tranny rebuild,would you say thats right?Thanks again you have saved me alot of frustration and heartache.
    NoSmoke

  8. #8
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    $3500 worth of Suncoast will get you out of the danger zone with a lot of breathing room. If you intend to never exceed the 120 HP Predator tune, you can get away with quite a bit less (about 1/2). Visit their website for more details tailored to your needs.

    Once you restore your factory tune, it should return to normal after some driving. Be prepared for some hard shifting and throttle flair. Once the shifting smooths out, it'll be reset. Ease into the power settings once you feel like it again, but keep you head on your shoulders. These things are impressive, and it's real easy to get carried away.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

  9. #9
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    Feb 2000
    Location
    Montana
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    I think a lift pump is a good idea for 100+ hp, but not essential. Lil Red is not running a lift pump, and it made 632 on the dyno. You could monitor "actual" & "commanded" fuel-rail pressure(s) using a Tech II during a full-on run to see to what effect your fuel supply needs help. The ECM will set a code (and put the truck into limp mode) if the pressure difference between actual & commanded exceeds 20Mpa.

    You'd need a pretty consistent truck to know for sure, but some have reported lower ETs after installing a lift pump.

    Jim

  10. #10
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    Thanks guys,id still be pulling my hair out,if it werent for this priceless site.Ive done what you suggested and it did the trick,no more 120 tune for me,until the new tranny,which brings me to this,somebody have $4000 they can loan me say ten years 0% interest.Thanks again.Nate
    NoSmoke

  11. #11
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    foxboro,ma.
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    Quote Originally Posted by nbloecher@yahoo.com View Post
    Thanks guys,id still be pulling my hair out,if it werent for this priceless site.Ive done what you suggested and it did the trick,no more 120 tune for me,until the new tranny,which brings me to this,somebody have $4000 they can loan me say ten years 0% interest.Thanks again.Nate
    can we get group rates ? I would like to get in on the ground floor of this deal ! My original commnet about a pump at 60 hp is over the life of the fuel filter you start to loose its flow rates so a single pump is insurance . I agree with MP , dont use the 120 tune unless your willing to walk for a few days and shell out 4K to a trans shop to bullet proof you rig. This is also a very good reason why I tell every one pick a HP level you can afford and leave it there , your TCM will adapt to some changes long term . I run a 70 hp live EFI JK tune on my lbz , its got power every where and tows very good. its nothing crazy , no smoke just a solid running tune that runs stock like .
    93 c-2500 6.5td,96 6.5td x cab,01 GMC lb7 Xcab ,2004 lly crew cab ,2006 lbz crew cab,honda CBR1100xx,2003 polaris prox 700 , 2001 31' holiday rambler 10K lbs house on wheels!

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