Topic: If I let off on the gas...
in Forum: C3 Engines
Already a Member?
Click Here to Login
Not yet a Member?
Click Here to Register for Free!
Lifetime MemberElma, WA - USA
Joined: 6/25/2007
Posts: 692
Vette(s): Red 1973 Convertible.
L-48 Auto
#'s matching
Red 1970 LT-1
Convertible
#'s matching
Then when I give it gas again there is this hesitation that seems to be getting worse.
So someone says, (Ya I know), its just getting a little sticky.
But I figured the folks here seem to know just about everything.
Stock carb on the L-48. I believe its a quadra-jet.
So would some "get the sticky out " spray help or what say you?
(As you can tell I am no mechanic and dont ever plan on being one.)
SPONSOR AD:: (Our Sponsors help support C3VR)
John, it could be a problem with the crab or maybe the timing? When was the timing checked last? Have you reset the crab? Maybe Joel will jump in? Joel, could it be something with the transmission? Fuel pump? Process of elimination.. check one thing at a time..
"I Love all Corvettes! LifeTime Member #60..Terry" 
Lifetime MemberGreensburg, IN - USA
Joined: 9/24/2003
Posts: 5188
Vette(s): Previous: 1984 Silver / Charcoal Coupe, 1988 Maroon Coupe / 1989 Artic White Coupe / 2001 Speedway White Roadster / Present:1976 Stingray Black / Black, Auto, 350 slightly modified (355 hp) Luxor Wires Redline Tires. / 1989 Roadster Bright Red...
John,
I would start with something simple. Look for a loose, cracked, or off vacum hose. Buy some gumout and spray in the carb and around the carb linkage. Drive it and see if there is a difference.
Check the distributer to see if it's loose. Then if no results I would throw a timing light on it and verify the timing.
If that doesn't prevail I would look back to the carb. Depending when the hesitation occurs can help to define what to review on the carb. Idle, secondaries, float level etc can all be suspect but if your not going to tackle these you can help to identify this for your mechanic.
Easiest way around all of this is to just sell me that red vert and you won't have any remaining hesitation problems!
Tuxblacray 2007-12-23 04:38:31
I would start with something simple. Look for a loose, cracked, or off vacum hose. Buy some gumout and spray in the carb and around the carb linkage. Drive it and see if there is a difference.
Check the distributer to see if it's loose. Then if no results I would throw a timing light on it and verify the timing.
If that doesn't prevail I would look back to the carb. Depending when the hesitation occurs can help to define what to review on the carb. Idle, secondaries, float level etc can all be suspect but if your not going to tackle these you can help to identify this for your mechanic.
Easiest way around all of this is to just sell me that red vert and you won't have any remaining hesitation problems!
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Does it have this same "hesitation" when you first take off from a stop?
Does it ONLY do it while driving, letting off, and then back on the gas?
Does it ONLY do it while driving, letting off, and then back on the gas?
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Lifetime MemberElma, WA - USA
Joined: 6/25/2007
Posts: 692
Vette(s): Red 1973 Convertible.
L-48 Auto
#'s matching
Red 1970 LT-1
Convertible
#'s matching
See, thats why I post here!
Great question Joel, I havent noticed it from a stop as much as letting off going into a corner and then exiting the corner, giving it gas.
As I have only had the car almost a year now there really isnt much to go on as far as history of any work.
It runs great otherwise.
So the Gum-out would be a good start?
That is after I check the vacuum lines. I just may have to drive it to town, get some gum out, and check for a hesitation from a dead start.
Tux, that was good, Real good.
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
So...it is only doing it(or you have only noticed it) when turning corners? That would lead me to suspect a low float level in the carb. You may have to break down and get that puppy rebuilt! 
I was( and may still be) leaning to a worn timing chain( more on this later, when I have more time), but the turning corners issue changes things a bit.
I was( and may still be) leaning to a worn timing chain( more on this later, when I have more time), but the turning corners issue changes things a bit.
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Lifetime MemberElma, WA - USA
Joined: 6/25/2007
Posts: 692
Vette(s): Red 1973 Convertible.
L-48 Auto
#'s matching
Red 1970 LT-1
Convertible
#'s matching
OK so heres what I did...
jt's73 2007-12-21 17:35:32
Drove to auto parts store. While on the way there did some diagnostic work.
From a standing start car takes off fine. Well as much as one can "take off" with a 200hp, detuned, weak kneed, L-48 350. (Larrys LT-1 really messed me up). Anyway....
Running at lets say 1/4 throttle, takes off fine. (Well as much as, Oh never mind).
Let off on gas and give it gas there is a big hesitation before "taking off".
Got to store and bought Gum Out.
Thought about spraying Gum Out at store but thought better of it. For one it would look stupid. And for 2 if I screw it up I would rather be back at the farm.
Back at the farm.
Read label. Says,"with engine running spray at both ends of the choke valve shaft while working choke". Cool.
But if I knew what the choke valve shaft was I probably WOULDNT BE BUYING THIS STUPID STUFF TO START WITH!
So I fiugre its got to be there somewhere. Start spraying. Engine dies.
(This is why I drove back to the farm!)
Engine starts right back up. This is good.
Work the little thingy that revs the motor while spaying into carb.
Didnt kill it. This is good.
Spray all around, into and on top of carb.
Results?
Doesnt do the hesitation nearly as much. Took away like 90% of it.
Still aint quite right but MUCH BETTER.
Can I use too much of this stuff if I give er another go in a week or so?
On another note, Joel, the advice to try it from a standing start was great. Did some burn outs I hadnt done before.
So in the future, anything with the car please advice to try gassing it hard from standing start.
Wipers dont work?
Headlights dont come up?
"Will it do it if you mat it from a standing start?".
Great advise. Had a blast. No tickets.
Again, thanks for all of your help and ideas.
in Forum: C3 Engines
SPONSOR AD: (Our Sponsors help support C3VR)