4.3 TBI running poorly

[MsPenutman1]

i dont realy no whats wrong but you cud thow some Throttle body cleaner in thair

[DaveTheYak12]

Throttle position sensor was junk on mine and did the same exact thing until I got a new one

[0fVolfAndMan]

try checking he entire ignition system

[brapboys503]

Well, its first problem is that it only has 6 cylinders. Just kidding! I got the 5.7L TBI.

[gladysman24133]

hi i have a 1991 s10 4.3l with a throttle body and i noticed that it has a metal curved line with a 3"hose on it,and nothing is hooked to it and my valve cover has a long rubber hose that goes to nothing,and from looking at your vid your line from the (TB IS HOOKED TO THE VALVE COVER)IS THAT WHAT IT IS SUPPOSED TO DO,WHAT IS IT FOR,I JUST GOT MY TRUCK,AND NOTICED IT,THANX.

[0fVolfAndMan]

@gladysman24133

i hav the same thing on my truck and it has to do some thing with recycling the air in the engine

[DJNIKKO9c1]

fuel pressure?

[FredSolomon]

egr valve

[BryanSparta29]

Its your timing on the distributer.

[evilsadvocate]

your engine timings waaay of cock nuckles

[tululilopo]

Sounds like a stuck valve or improper cam timing. Perhaps EGR problems.

If only one fuel injector is spraying, check where the two wires connect to a common wire.

[chevyrace7]

lifter try running atf through the engine oil

[Realy55]

are you fixed...!!!

[cositarascal]

maybe the injectors are really dirty, my 4.3 t.b.i was running like this, i just used better gas and it cleared it right up. it might also be that it needs a tune up. Sounds like it's spitting though, i would say something to do with fuel. maybe bad plugs

[jamiedecarlo735]

put a 4 barrel on it it will wake up

[74ChevyVegaMan]

do you have any knowledge of swapping 4 barrels onto tbi 4.3? I am fixing to get one and swap it into my 74 chevy vega but i want it to be carbed?

[daveo211]

Edelbrock makes a 4 barrel intake for the 4.3. Then simply swap over all of your cables(don't forget the TV cable if so equipped) and vacuum lines for cruise brakes, etc. You will have to find a carbuerated engine distributor for a 4.3. Otherwise you will have no advance. Thinking about doing this myself, but if I go through all of that, i might as well replace the 4.3 with a v8....

[jimmyman1991]

ya you get a manifold for a 4.3 that takes a carb instead of a tbi unit...go to summit racing they have them there...then get a carb and an ecu for a carb controlled unit. you have to deal with the tps and junk too but its worth it to race with.....otherwise you will need a big fuckin wallet for gas

[WTR1050]

It might just need a tune up. New spark plugs, wires, cap, rotor; and a fresh oil and filter change migh do the trick.

[adomth3rice]

I'll just give you a list of likely causes.

Bad Throttle position sensor

Bad Idle Air Control Valve

Vacuum leak

Erratic fuel pressure (from a bad fuel pump?)

Something bad in the ignition system.

Bad Oxygen Sensor

Although, if the ECM doesn't try to turn the check light on, that might be the root of the problem.

I guess it's a question of how badly you want to fix it, but I'd start at the top of the list and work my way down.

[Metallica1071991]

My 4.3 ran like shit, I never could figure out the problem. So I found an intake and put a 4 barrel on it. haha

[74ChevyVegaMan]

I am fixing to attempt to swap a 4 barrel onto a tbi 4.3 out of an s10 but im dropping it into a 74 Chevy Vega? Any advice on this and what carb and intake should I use?

[gannman51]

maybe cause you rev it like that with no filter so much, maybe dirt in the intake?