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  1. #1
    tonylong
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    Default Convert L98 to Carburetor???

    I'm thinking out of the box regarding my engine "Crank but no start" problems, posted elsewhere here.
    What if I converted it to a carburetor? I'd need a new intake, some carbs, fuel system changes. Whats the prospects for this conversion? New heads?? other stuff?? likely labor time (not by me).
    Any experience/opinions on this??

  2. #2
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    Corvette(s)
    2001 Convertible

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    Changing you C4 Corvette to a carburator will do,
    1 devalue it.
    2 make drivability bad.
    3 fuel economy will plummet.
    4 ruin a classic.
    5 cost you more money to convert than just fixing the root problem.

  3. #3
    killain's Avatar
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    2003 50th Annversary Red coupe, beautiful !

    Default

    Quote Originally Posted by tonylong View Post
    I'm thinking out of the box regarding my engine "Crank but no start" problems, posted elsewhere here.
    What if I converted it to a carburetor? I'd need a new intake, some carbs, fuel system changes. Whats the prospects for this conversion? New heads?? other stuff?? likely labor time (not by me).
    Any experience/opinions on this??
    I have no idea why you'd want to do this. You have a perfectly good performance system already, You have a problem, but the cars fuel system is fixable. If you have a mouse in the house, do you set the house on fire?

  4. #4
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    Too funny, but good . So many people want to fix a problem and do it cheaply but by the time there done the cost of fixing cheap ends the expensive way.


    Quote Originally Posted by killain View Post
    I have no idea why you'd want to do this. You have a perfectly good performance system already, You have a problem, but the cars fuel system is fixable. If you have a mouse in the house, do you set the house on fire?

  5. #5
    Member minifridge1138's Avatar
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    1982 Black Fastback

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    Speaking as someone that drives a Corvette that has been converted from Fuel Injection to a Carburetor, here are some of the things you'll have to change:

    -New intake manifold
    -New distributor
    -New carburetor
    -New fuel pump
    -Re-wire electronics
    -Re-plumb the fuel system.

    At this point the car could start and run.

    Here are some problems you'll have:
    -Everything controlled by the computer stops working:
    *Tachometer
    *Speedometer
    *Temp gauge
    *Oil Pressure
    *Have any other gauges?
    *Does the computer control climate control?
    -Loss of fuel economy. I get about 12 mpg city and 23 (at best) highway. That is with .7 overdrive and a 2.7 rear end.
    -Replace the Transmission (I don't remember when the computer started controlling shift points)
    -No more locking torque converter.
    -Got a car alarm? I bet it uses the computer.
    -Seat belt warning lights?
    -You better remove the check engine light

    I'm sure there is more that I'm not thinking of.
    It would be cheaper to replace the injectors, computer, and spark control than it would be to retrofit a carburetor.... Trust me.

  6. #6
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    Corvette(s)
    1991 C4 Coupe Dark Chocolate

    Default Why not

    Hey Tony, I feel your pain. One thing folks dont talk about with these computer controled rides is how much it will cost replacing all those electrical connectors (assuming you can find them) on your wiring harness when they crack/break/go south.

    TPI is great and gives good low end torque. If all you do is drive around town taking it easy, it works great with good mileage. If on the other hand you want to have more than 250hp, you are limited with what you can do. I swapped to a carb and vortec heads. The heads were dirt cheap (with valves) though I'll have to add studs down the road when I go to a hotter cam. Carb runs around 300, an accel distributor is around 110 (at least thats what I paid). Speedometer still works and once I hook the cruise cable back up it should as well. (I do have a 6 speed so that helps). There are kits that will allow you to hook up the locking torque converter if you have an automatic.

    I"m still sorting out the fuel suppy as the electric in/tank fuel pump puts out too much pressure for a carb.

    Understand, I am doing this with my labor not paying someone else. I have to beleive it will cost you less to have someone else repair what you have if you cant wrench yourself. I would certainly have a mechanic go over it before making any decisions.

    best of luck

  7. #7
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    1990

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    Quote Originally Posted by minifridge1138 View Post
    Here are some problems you'll have:
    -Everything controlled by the computer stops working:
    *Tachometer
    *Speedometer
    *Temp gauge
    *Oil Pressure
    *Have any other gauges?
    -No more locking torque converter.
    I assume you have removed the computer which you don't have to do with a carb conversion.

    Computer and wiring stays; all you lose is the fuel mileage display.Everything else functions as stock.
    All you do is tuck the unused wiring ( injector looms ) out of the way.Zip tie on top of bellhousing

    The TCC is easily fixed by a vac switch or a 4th gear switch inside the trans.
    I can swap mine from HSR to Vic Jnr- 750DP combo and back with no problems.

    93'+ got electronic trans.

  8. #8
    New Member
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    1991 C4 Coupe Dark Chocolate

    Default Good point forgot to mention

    I should have stressed that I left the computer in. The only thing I disconnected was the EGR, Injectors and the electronic control for the distributor. I so still have the computer and dont plan to yard it out at this point. Still have the temp, fans etc working.
    The one other item that wont work is the knock sensor in that it may sense a ping going on, but the computer cant retard the timing since it isn't hooked up.

  9. #9
    Member RoyalViking's Avatar
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    1989 C4

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    I don't believe that you cannot get more than 250 HP from a TPI engine. It is probably a that so many of us can tune a carb much easier than a computer controlled engine. I would rather do the trouble shooting and learn more about computer controls than swap out an efficient system with a carb. Computer controls are not going away. If you can repair your corvette you are one step ahead of most people who have to take their car to someone for service.

  10. #10
    New Member
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    1991 C4 Coupe Dark Chocolate

    Default You are correct

    You can certainly get more than 250 from TPI. You can order a bigger intake and bigger tubes (or go mini ram etc.), add a bigger throttle body which means you will also want to add bigger injectors (to handle the flow). But man is that stuff expensive. 1500 for complete fuel injection (ok maybe not complete depending on what system). And then theres setup. Compare that to a Carb (300), Distributor (110) and sorting out the fuel (use stock fuel pump with pressure regulator about 100bucks) and of course the intake.

    Again, nothing wrong with EFI (TPI in this case) except when you deal with a 20yo wiring system and the cost of some of those parts, phew. It is still less expensive to build power using "conventional" means.

    But, if the thing runs good and you arent' worried about doing big mods, the stock system is fine. Replacing a bad injector is certainly cheaper than replacing the whole induction system. Just depends on whats wrong with the car, and what you want to do with it.

    TPI cant be the best thing or chevy wouldn't have gone to the short runner manifold on everything since the L98. (think about it, tubes that cover the injectors, everything is under the plenum chamber, no room to work, ugh).

    For that matter, if you have the pesos, dont screw around, buy a used complete LS1 or 2. That's a sweet setup.

    Anyways, as the saying goes, to each his own....

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