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tbi vs carb

Discussion in 'The Garage' started by cochino12, Feb 5, 2004.

  1. cochino12

    cochino12 1/2 ton status

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    I am able to buy a whole TBI setup from a guy for about $100 and am not sure if its worth the time or the $$ to get it installed. My blazer is just a daily driver used once in a while for light trails. I did try to search but I cant seem to find much on comparing the pros and cons of the two. thanks for any input
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    TBI is better than the carb. /forums/images/graemlins/smile.gif (in short, for daily driver: better economy and no choke. Offroad, no worries about angles)

    Whats the TBI off of? Same body style as ours (87-91) or something else.

    If you decide to go TBI, you need to get EVERYTHING off of a donor vehicle. If you attempt to piece together a system from what was initially a "good deal", you end up paying more in the long run.
     
  3. cochino12

    cochino12 1/2 ton status

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    [/ QUOTE ]Whats the TBI off of? Same body style as ours (87-91) or something else.

    If you decide to go TBI, you need to get EVERYTHING off of a donor vehicle. If you attempt to piece together a system from what was initially a "good deal", you end up paying more in the long run.

    [/ QUOTE ]

    Supposed to be a late '87 c20 w 350 and th400, and of course it suposed to have everything, intake, ecm, harness, injectors, etc..... should the install be fairly simple since it is a complete setup? thanks
     
  4. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    I actually think a good carb is sometimes better. I have a friend with an 87' K5 and that thing sucks as far as power and the way it runs in general. I just had my edelbrock q-jet professionally tuned and I'm getting noticeable better mileage and power now. FI trucks can be a PITA when it comes to all the map sensers, electric fuel pump, etc... Carbed trucks are easy to diagnose, easy to work on, and pretty reliable as long as everything is in good condition. I doubt a tbi rig would get much better mileage than my carb on my motor that loves lots of fuel and with the weight of my vehicle.

    If it was me I would get the setup and install the edelbrock MPFI upgrade kit for it and that would make the biggest difference in performance. The main advantage that TBI has IMHO is that it will run at any angle, although My Q-jet has supplied fuel very well at some pretty steep angles though and I do a LOT of hill climbing. To me it's not worth it unless you go all the way with a TPI or MPFI system. If I ever do anything other than a carb it will be the edel. multi port pro flow system.
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    '87 will have the different intake center bolts. numerous ways to rectify that, from modifying the intake, to changing heads.

    I think carbs being easier to work on/less problematic is in the eyes of the beholder. I can point to plenty of people on here who can't make their carbs run right. Just because someone doesn't understand FI, or take the time to properly diagnose it (instead of spending $500 replacing all the parts that could POSSIBLY be bad) doesn't mean it is more expensive or more problematic.

    How many people on here have changed 5-20 parts in an effort to fix something, only to find it was something totally different?

    Reliability is a pointless argument, just as many TBI's are running good at 100K+ as are carbs. Newest one of these trucks out there is now 13 years old, questionable reliability concerns went out the window probably 5 years after they last rolled off the line. All of GM's EFI systems have proven to be extremely durable.
     
  6. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    I am just saying that carbed trucks are simpler and easier to work on your self. Plenty of FI are out there running just fine BUT when something DOES go wrong with them they can be a b!tch to diagnose. I am not ignorant about the early TBI setups, I have a decent amount of knowledge about them through reading different threads(mostly that you have written /forums/images/graemlins/smile.gif) and from friends having them. Heck I came as close to buying an 87' K5 about a month ago to where I was reaching for my wallet. They are very nice systems when they are in good shape and calibrated correctly and have lots of potential with being able to have custom chips burned to match custom motors and the ability to swap in 454 throttle bodies...along with other nice features. I personally would rather have a good carb and vaccuum advance dist. than a early to mid 80's tech FI system simply because carbs are easier to work on and yield basically almost as good fuel economy and just as much power output.

    The guys that are having problems with their carbs need to either have them rebuilt or have it tuned. /forums/images/graemlins/dunno.gif

    I am seriously considering a FI upgrade myself along with AFR heads but I am not going to waste my time to switch over to a TBI system when there are much better TPI and MPFI systems out there.

    I don't wan't this to turn into a pissing match between you and I Dorian, like it has many times in the past. He asked for input...you gave yours...I gave mine....and they are different but both helpfull, that is what is so great about these boards. /forums/images/graemlins/waytogo.gif
     
  7. FWP

    FWP CRS

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    IMHO, leave things the way they are for a DD. TBI or TPI mods will be difficult unless you're technically proficient.. Besides, why change a good running truck?.....Unless you want to run uphill at 90* /forums/images/graemlins/grin.gif
     
  8. 89K1500Chevy

    89K1500Chevy 1/2 ton status

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    i have both carb'd street beast and TBI offroad truck. I prefer to work on the TBI its by far easier to replace the sensors on it then have it all rebuilt or dyno tuned. Just plug and pray. Its by far more responsive then my street truck which has 750 Hi po Qjet that was built by a speed shop in cali. But then agin it needs tuning i have been messing with it trying to get it rite but i just need to spend the cheese and get it dyno tuned. Im a speed/acceleration junkie and i really hate going from the blue truck to the red one. Now if i could get the Red trucks throttle response on my blue truck /forums/images/graemlins/woot.gif but only thing id do is a MPFI system no way a tbi on anything hi po.
     
  9. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    [ QUOTE ]
    I am just saying that carbed trucks are simpler and easier to work on your self.

    [/ QUOTE ]

    Matter of opinion. I don't have a problem tearing into my TBI, but I refuse to work on a carb because my knowledge is TBI and from what I have seen on carbs, you guys can have them.

    I'll stick to my 165K mile TBI that's still reliable as the day it was new /forums/images/graemlins/thumb.gif
     
  10. K5 NUTT

    K5 NUTT 1/2 ton status

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    Boy does that screen name look familiar....hmm. Must be from the 2wd board i haunt...your from denver right...flyin up there sunday to inprocess back into the army reserve on monday...give me your number and maybe we can hook up late sunday afternoon when i arrive and i'll explain it to you in great detail...both my chalet and daily driver 79 are converts...did them myself...built the second harness my self...so i can answer all your questions.

    PS...those weren't the seat belts i was looking for...the ones i need actually mount into the roof in the rear...90-91 only just like the power mirrors..

    Doug W.
     
  11. 89K1500Chevy

    89K1500Chevy 1/2 ton status

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    Ha mine has over 193,000 miles
     
  12. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    [ QUOTE ]
    Ha mine has over 193,000 miles

    [/ QUOTE ]

    Mine's retired from daily driver duties.
     
  13. azblazor

    azblazor 1/2 ton status Premium Member

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    I have converted several trucks from carb to TBI. It does not matter whether they are trail trucks or mostly DD to me. TBI is significantly better in several areas to me:

    1st is drivability, if you change elevation or temperatures zones a TBI truck is soooooo much better at starting and running "normally". (desert to mountains)

    2nd is longevity of basic engine. TBI engines run at a much more closely controlled air/fuel mixture and timing changes (also compensates for pinging or knocking). This reduces oil contamination and evens out temperature cycles and peak stresses.

    3rd easier troubleshooting. This applies mostly to personal preference. But for me it is easier to fix a TBI system, with simple diagnostic tools then it is to fix carburetors and adjust them. I have spent way more on maintaining carbs then I have on maintaining the TBI system on any long term truck I have experience running both ways.

    This has been my experience and remember that my usage is related to driving lots of miles and traveling from sea level to 10,000 feet or more during both summer and winter.

    If you are only driving locally and you have a good understanding of carb: starting circuits, idling circuits, power circuits, acceleration pumps, orfices, jets, floats, metering rods, chokes, complex linkage relationships, etc., then maybe it would be better to stay with a carb /forums/images/graemlins/smile.gif

    Just for the record, I started rebuilding carbs in 1971. And I have read lots of books and had formal automotive repair training. This is my opinion on the topic.
     
  14. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    /forums/images/graemlins/dunno.gif
     
  15. i8yrsuv

    i8yrsuv 1/2 ton status

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    My blazer is a 86 and it has a carb . My donor is a 88 tbi 1 ton w/the motor and the wiring just laying around .When I bought the truck it wasnt untill 3 months later I relized it was a TBI .The TBI is the smoothest runnig small block I have ever seen !!! That made me a believer in TBI and I will be swapping motors in a year and to TBI w/ a few power parts too!!
    I love the old school carbs & I have rebuilt a few in my time . They are what I know now ... /forums/images/graemlins/thumb.gif
     

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