new member need help with 74
Thread Starter
6th Gear
Joined: Jan 2006
Posts: 6
Likes: 0
new member need help with 74
Hello everyone
i just purchased my first vette took me 20 years to get it been wanting one since 16 years old.
i need some help.. here is the history of the car. purchased in 74 by 50 year old man driven a bit for 10 years then parked since due to health. he is 81 now and sold it to me. i cleaned it out replaced the carpet, seat backs, cleaned the leather, cleaned the dash, replaced seat belts they were fair but i went ahead and changed. inside of car is ok now
outside was fine needed a bath. engine would not start so i had quadrajet rebuilt to factory specs. it starts fine and idles ok. when i drive it from 0 to say 8 or 10 miles an hour if i floor it it wants to bog down and or backfire a bit. when i get past the 10 mile or so mark if i floor it its like a rocket and goes with good acceleration. i replaced the tach cable and it is idle at or around 500 rpm
any help would be appreciated
by the way its yellow and cool as can be....
i just purchased my first vette took me 20 years to get it been wanting one since 16 years old.
i need some help.. here is the history of the car. purchased in 74 by 50 year old man driven a bit for 10 years then parked since due to health. he is 81 now and sold it to me. i cleaned it out replaced the carpet, seat backs, cleaned the leather, cleaned the dash, replaced seat belts they were fair but i went ahead and changed. inside of car is ok now
outside was fine needed a bath. engine would not start so i had quadrajet rebuilt to factory specs. it starts fine and idles ok. when i drive it from 0 to say 8 or 10 miles an hour if i floor it it wants to bog down and or backfire a bit. when i get past the 10 mile or so mark if i floor it its like a rocket and goes with good acceleration. i replaced the tach cable and it is idle at or around 500 rpm
any help would be appreciated
by the way its yellow and cool as can be....
Le Mans Master
Joined: Jan 2006
Posts: 8,319
Likes: 7
From: Wilmington DE, Drive it like you stole it, 68 327 4 speed coupe
go through it all
Reroe,
since this car is new to you now would be a good time to go throught the engine and tune it properly. Start with ensureing youve got a good set of plugs wires, ditributor cap etc, clean fuel filter. Not saying this is your problem, but always a good idea with a new car. One this is done break out the timing light, vaccum gage, and engine analyser and check the vacuum at idle, carburative mixture setting, and such. the check and adjust the timing and set it to your spec. Now if all that check out good and is set up right and your still experience low RPM bogging, you know youve got a good baseline to start with
i would bet though that thet gets you wher you want to be
since this car is new to you now would be a good time to go throught the engine and tune it properly. Start with ensureing youve got a good set of plugs wires, ditributor cap etc, clean fuel filter. Not saying this is your problem, but always a good idea with a new car. One this is done break out the timing light, vaccum gage, and engine analyser and check the vacuum at idle, carburative mixture setting, and such. the check and adjust the timing and set it to your spec. Now if all that check out good and is set up right and your still experience low RPM bogging, you know youve got a good baseline to start with
i would bet though that thet gets you wher you want to be
Last edited by sweethence; Jan 13, 2006 at 08:22 AM.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
you know the mechanical advance in the distributors can freeze in these cars....it may not be a bad idea to take your distributor cap and rotor off and see if the shaft with the weights on it will rotate freely.....a real tuneup will probably help this car also....you may also want to see if the accelerator pump is actually working and hooked up properly.....we saw during the Lars tuning session Carbs that had been professionally rebuilt ....rebuilt wrong... so don't assume anything when trouble shooting...
Le Mans Master
Joined: Aug 2000
Posts: 6,362
Likes: 7
From: Brazos TX
Cruise-In IV Veteran
Cruise-In V Veteran
Welcome to the Forum and congrats on Corvette ownership! I agree with what has been said. Ignition timing can impact significantly how an engine runs. It really sounds like you have either the timing set incorrectly or the weights and/or vacuum advance aren't working properly. If the timing checks out then the secondary air valve should be adjusted on the carb. That will definitely cause a bog. Keep us updated with how it goes we want to know if you got it working or not.
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Originally Posted by reroe
Hello everyone
it starts fine and idles ok. when i drive it from 0 to say 8 or 10 miles an hour if i floor it it wants to bog down and or backfire a bit. when i get past the 10 mile or so mark if i floor it its like a rocket and goes with good acceleration.
it starts fine and idles ok. when i drive it from 0 to say 8 or 10 miles an hour if i floor it it wants to bog down and or backfire a bit. when i get past the 10 mile or so mark if i floor it its like a rocket and goes with good acceleration.
Le Mans Master
Joined: Oct 2004
Posts: 5,841
Likes: 19
From: CLT, North Carolina
Lean Backfire
Classic example of lean condition or lean backfire. Something wrong with the Q-Jet. Perhaps something not installed correctly or wrong gasket with different holes somewhere. Not getting enough fuel.
Greg
Greg
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Thread Starter
6th Gear
Joined: Jan 2006
Posts: 6
Likes: 0
i installed new plug wires and it made a difference. i also bought a haynes manual and began reading. so here is the next of my questions. i installed the carb myself(first time)after it was rebuilt and i dont know if i set the two different idles correctly..
one idle is the fast idle that has the spring to the intake the other is the normal idle (im using the wrong terminology here) and its at 500.. should it be 700 instead and if so can someone help me figure out the proper way to set it
also has anyone ever heard of an vette called a eichler corvette with 6 lights in the back instead of 4
one idle is the fast idle that has the spring to the intake the other is the normal idle (im using the wrong terminology here) and its at 500.. should it be 700 instead and if so can someone help me figure out the proper way to set it
also has anyone ever heard of an vette called a eichler corvette with 6 lights in the back instead of 4
Burning Brakes
Joined: Jul 2000
Posts: 963
Likes: 0
From: melbourne,Australia
Originally Posted by reroe
Hello everyone
i just purchased my first vette took me 20 years to get it been wanting one since 16 years old.
i need some help.. here is the history of the car. purchased in 74 by 50 year old man driven a bit for 10 years then parked since due to health. he is 81 now and sold it to me. i cleaned it out replaced the carpet, seat backs, cleaned the leather, cleaned the dash, replaced seat belts they were fair but i went ahead and changed. inside of car is ok now
outside was fine needed a bath. engine would not start so i had quadrajet rebuilt to factory specs. it starts fine and idles ok. when i drive it from 0 to say 8 or 10 miles an hour if i floor it it wants to bog down and or backfire a bit. when i get past the 10 mile or so mark if i floor it its like a rocket and goes with good acceleration. i replaced the tach cable and it is idle at or around 500 rpm
any help would be appreciated
by the way its yellow and cool as can be....
i just purchased my first vette took me 20 years to get it been wanting one since 16 years old.
i need some help.. here is the history of the car. purchased in 74 by 50 year old man driven a bit for 10 years then parked since due to health. he is 81 now and sold it to me. i cleaned it out replaced the carpet, seat backs, cleaned the leather, cleaned the dash, replaced seat belts they were fair but i went ahead and changed. inside of car is ok now
outside was fine needed a bath. engine would not start so i had quadrajet rebuilt to factory specs. it starts fine and idles ok. when i drive it from 0 to say 8 or 10 miles an hour if i floor it it wants to bog down and or backfire a bit. when i get past the 10 mile or so mark if i floor it its like a rocket and goes with good acceleration. i replaced the tach cable and it is idle at or around 500 rpm
any help would be appreciated
by the way its yellow and cool as can be....
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by sweethence
Reroe,
since this car is new to you now would be a good time to go throught the engine and tune it properly. Start with ensureing youve got a good set of plugs wires, ditributor cap etc, clean fuel filter. Not saying this is your problem, but always a good idea with a new car.
since this car is new to you now would be a good time to go throught the engine and tune it properly. Start with ensureing youve got a good set of plugs wires, ditributor cap etc, clean fuel filter. Not saying this is your problem, but always a good idea with a new car.
Yep excellent advice 
You know what your working with.
Thread Starter
6th Gear
Joined: Jan 2006
Posts: 6
Likes: 0
Jdunne
Thanks for the advice that is the first thing i had done had all the lines and calipers replaced and it has manual brakes for now i bought a combination brake booster and mastercylinder but have not put on yet. someone said i need somekinda adapter for the brakebooster
Thanks for the advice that is the first thing i had done had all the lines and calipers replaced and it has manual brakes for now i bought a combination brake booster and mastercylinder but have not put on yet. someone said i need somekinda adapter for the brakebooster
Burning Brakes
Joined: Jul 2000
Posts: 963
Likes: 0
From: melbourne,Australia
Originally Posted by reroe
the car is not backfiring no more however i have set the idle up to high its idling at or around 1100 rpm and not boging on take off but i think thats a bit high for an idle isnt it
Intermediate
Joined: Dec 2005
Posts: 33
Likes: 0
From: Waukesha Wisconsin
hey i had the same problem with my 73 had the carb rebuilt the guys told me it was running lean and the idle screws were way off and there is a lincage cable that was stretched so when you punch it at low speeds and r's it snaps and jumps hope this helps
