93 Brave with Chevy 454 acceleration issuea
Have a 93 Brave 27RC on a Chevy P30 chasis. 112000 miles. When cold idles well and accelerates well from standing still. Then after warmup when accelerating from a start it falters often. Some refer t...
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A good mechanic (who knows carburetors) is a good call. As others have said, Chevrolet made the last carbureted 454s in 1989. If you have a carb, it probably isn't stock, and probably just needs some good ol' fashioned tuning. Remember LOTS of mechanics you'll find weren't even born in 1989 (someone born in 1989 is turning 29 this year). I was asked yesterday if an "alternator" is that thing that cars don't have anymore. I corrected her and said that was a "carburetor".
You should be able to find your RPO code somewhere, it ought to be L19. That'd tell you for sure it was TBI at some point.
Some 454 info (updating my post):
RPO LE8: 240 net hp (trucks only)
Small oval (“peanut”) port cast-iron heads, Quadrajet 4-barrel carb, mild hydraulic lifter cam, two- or four-bolt main caps, cast-iron crankshaft. Available in trucks only through 1986 and some heavy trucks through 1989.
RPO L19: 230 net hp (trucks only)
This engine superseded the LE8 when General Motors switched from carburetors to computer-controlled 2-barrel TBI (throttle body injection) in 1987. Small oval (“peanut”) port cast-iron heads, mild hydraulic lifter cam, two- or fourbolt main caps, cast-iron crankshaft. Available in trucks only from 1987 to 1990, this was the last production Mark IV engine.
7.4 Liter Gen V (454 ci) RPO L19: 230 net hp (trucks only)
Even though General Motors switched to the newly designated Gen V block, heads, and crankshaft in 1991, this workhorse retained the same RPO number as its predecessor: small oval (“peanut”) port cast-iron heads, TBI, mild hydraulic lifter cam, four-bolt main caps, cast-iron crankshaft. Available in trucks only from 1991 to 1995.
7.4 Liter Gen VI (454 ci) RPO L19/L29: 290 net hp at 4,000 rpm (trucks only)
The Vortec 7400 featured more refinements including the use of MPFI (multi-point fuel injection) and hydraulic roller lifters: small oval (“peanut”) port cast-iron heads, four-bolt main caps, cast-iron crankshaft. Available in trucks only from 1996 to 2000.
You should be able to find your RPO code somewhere, it ought to be L19. That'd tell you for sure it was TBI at some point.
Some 454 info (updating my post):
RPO LE8: 240 net hp (trucks only)
Small oval (“peanut”) port cast-iron heads, Quadrajet 4-barrel carb, mild hydraulic lifter cam, two- or four-bolt main caps, cast-iron crankshaft. Available in trucks only through 1986 and some heavy trucks through 1989.
RPO L19: 230 net hp (trucks only)
This engine superseded the LE8 when General Motors switched from carburetors to computer-controlled 2-barrel TBI (throttle body injection) in 1987. Small oval (“peanut”) port cast-iron heads, mild hydraulic lifter cam, two- or fourbolt main caps, cast-iron crankshaft. Available in trucks only from 1987 to 1990, this was the last production Mark IV engine.
7.4 Liter Gen V (454 ci) RPO L19: 230 net hp (trucks only)
Even though General Motors switched to the newly designated Gen V block, heads, and crankshaft in 1991, this workhorse retained the same RPO number as its predecessor: small oval (“peanut”) port cast-iron heads, TBI, mild hydraulic lifter cam, four-bolt main caps, cast-iron crankshaft. Available in trucks only from 1991 to 1995.
7.4 Liter Gen VI (454 ci) RPO L19/L29: 290 net hp at 4,000 rpm (trucks only)
The Vortec 7400 featured more refinements including the use of MPFI (multi-point fuel injection) and hydraulic roller lifters: small oval (“peanut”) port cast-iron heads, four-bolt main caps, cast-iron crankshaft. Available in trucks only from 1996 to 2000.
