Idle speed?
Drifting
Joined: Mar 2006
Posts: 1,526
Likes: 2
From: Oak Ridge NC
1975 and later Vettes use an integral choke carb. Pre-75 use divorced choke carbs. Your carb is a divorced choke carb, which means that the entire choke system is missing and cannot be made to operate on your car. You need a complete integral choke carb along with the hot air choke tubes to make the choke function. I can't tell from the photo resolution if you have the correct intake manifold with the hot air tube provisions.
The distrubutor, when correctly installed, should be "square" in the engine compartment. In other words, the wire terminal on the driver's side should be 90-degrees straight out on the driver's side, and the square coil on top of the dizzy should be square in the engine compartment. The forward driver's side wire tower is the #1 wire tower, and on yours it's going over to the passenger side of the engine (#1 is on the driver's side). The distributor is simply installed incorrectly.
PCV is positive crankcase ventilation. It pulls a negative pressure on the crankcase when the engine is running. Upon close exam of your photo, it looks like the PCV may be installed in the rear of the driver's side valve cover and plumbed into that nasty-looking pipe fitting on the back of your manifold - at first it looked like it was just the power brake line going to that "tree." You may be okay on the PCV, but I would yank that pipe system out of the manifold and run your lines correctly for better performance of the brake and PCV systems.
If you want to fix that thing up, we can start scrounging up all the parts you need and then send you everything as a "Care Package." Let me know if you need help with this. It just takes time and money.
The distrubutor, when correctly installed, should be "square" in the engine compartment. In other words, the wire terminal on the driver's side should be 90-degrees straight out on the driver's side, and the square coil on top of the dizzy should be square in the engine compartment. The forward driver's side wire tower is the #1 wire tower, and on yours it's going over to the passenger side of the engine (#1 is on the driver's side). The distributor is simply installed incorrectly.
PCV is positive crankcase ventilation. It pulls a negative pressure on the crankcase when the engine is running. Upon close exam of your photo, it looks like the PCV may be installed in the rear of the driver's side valve cover and plumbed into that nasty-looking pipe fitting on the back of your manifold - at first it looked like it was just the power brake line going to that "tree." You may be okay on the PCV, but I would yank that pipe system out of the manifold and run your lines correctly for better performance of the brake and PCV systems.
If you want to fix that thing up, we can start scrounging up all the parts you need and then send you everything as a "Care Package." Let me know if you need help with this. It just takes time and money.
Agent Kronus,
Take the offer...now!
Paul
Thread Starter
Racer
Joined: Jul 2007
Posts: 256
Likes: 0
From: Glasgow, Scotland
1975 and later Vettes use an integral choke carb. Pre-75 use divorced choke carbs. Your carb is a divorced choke carb, which means that the entire choke system is missing and cannot be made to operate on your car. You need a complete integral choke carb along with the hot air choke tubes to make the choke function. I can't tell from the photo resolution if you have the correct intake manifold with the hot air tube provisions.
The distrubutor, when correctly installed, should be "square" in the engine compartment. In other words, the wire terminal on the driver's side should be 90-degrees straight out on the driver's side, and the square coil on top of the dizzy should be square in the engine compartment. The forward driver's side wire tower is the #1 wire tower, and on yours it's going over to the passenger side of the engine (#1 is on the driver's side). The distributor is simply installed incorrectly.
PCV is positive crankcase ventilation. It pulls a negative pressure on the crankcase when the engine is running. Upon close exam of your photo, it looks like the PCV may be installed in the rear of the driver's side valve cover and plumbed into that nasty-looking pipe fitting on the back of your manifold - at first it looked like it was just the power brake line going to that "tree." You may be okay on the PCV, but I would yank that pipe system out of the manifold and run your lines correctly for better performance of the brake and PCV systems.
If you want to fix that thing up, we can start scrounging up all the parts you need and then send you everything as a "Care Package." Let me know if you need help with this. It just takes time and money.
The distrubutor, when correctly installed, should be "square" in the engine compartment. In other words, the wire terminal on the driver's side should be 90-degrees straight out on the driver's side, and the square coil on top of the dizzy should be square in the engine compartment. The forward driver's side wire tower is the #1 wire tower, and on yours it's going over to the passenger side of the engine (#1 is on the driver's side). The distributor is simply installed incorrectly.
PCV is positive crankcase ventilation. It pulls a negative pressure on the crankcase when the engine is running. Upon close exam of your photo, it looks like the PCV may be installed in the rear of the driver's side valve cover and plumbed into that nasty-looking pipe fitting on the back of your manifold - at first it looked like it was just the power brake line going to that "tree." You may be okay on the PCV, but I would yank that pipe system out of the manifold and run your lines correctly for better performance of the brake and PCV systems.
If you want to fix that thing up, we can start scrounging up all the parts you need and then send you everything as a "Care Package." Let me know if you need help with this. It just takes time and money.
the car was making poping and bangs in the zorst, I changed the spark plugs , which seem to have stopped that problem, but it is still backfiring into airfilter, when u press accerator pedal quickly, do you think anything on my present setup might be causing this problem?
im going to buy a timing light gun and vac tester, and report back some stats for u.
I will also take more pics of the intake manifold, to see if we can spot the hot air tube provisions.
cheers
dave
Last edited by agent kronus; Aug 6, 2007 at 04:53 PM.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
By the way - try spellcheck... and the "Shift" key will help you make capital letters.
Last edited by lars; Aug 6, 2007 at 09:27 PM.
Thread Starter
Racer
Joined: Jul 2007
Posts: 256
Likes: 0
From: Glasgow, Scotland
Yes, of course. The entire setup is completely out of configuration. But start off by getting your total timing set to 36 degrees. Make sure your vacuum advance is functional and not ruptured and hook it up to a manifold vacuum source on the carb. If it still pops up through the carb, you're running way too lean. You can make that carb work if it's set up right and with all its parts installed, but the choke will never function.
By the way - try spellcheck... and the "Shift" key will help you make capital letters.
By the way - try spellcheck... and the "Shift" key will help you make capital letters.
Racer
Joined: Mar 2004
Posts: 354
Likes: 0
From: Fredericksburg Va
I like the throttle linkage spring attached to the radiator hose.....nice touch.... Your choke right now looks like it is that rope that is tied to it. Not very effective.
This needs to go in the BUBBA files
Any, All, and Some of the things pointed out that is out of wack can cause the symptoms and issues you are experiencing. You just need to put it all back together the way it is supposed to be.
Your in good hands with Lars....
Rd
This needs to go in the BUBBA files
Any, All, and Some of the things pointed out that is out of wack can cause the symptoms and issues you are experiencing. You just need to put it all back together the way it is supposed to be.
Your in good hands with Lars....
Rd
Thread Starter
Racer
Joined: Jul 2007
Posts: 256
Likes: 0
From: Glasgow, Scotland
Ok here's a wee update, Ive worked out that my high idle is being caused by the throttle not closing right down, maybe a new spring is needed or the stuff inside the carb is a bit stiff??
My lights don't come up, so defo a vac leak there, took pipe of the lights and plugged it up for now
still backfiring up into air filter, timing light has been ordered
let you want the timing is soon
also looked up my carb code number -"7043202" which I think comes from a 1973 vette?
also the intake manifold has a code number - "GM CFM 1405705"
which seems to been used on cars between 1980 -1988 ??
cheers
dave
My lights don't come up, so defo a vac leak there, took pipe of the lights and plugged it up for now
still backfiring up into air filter, timing light has been ordered
let you want the timing is soon
also looked up my carb code number -"7043202" which I think comes from a 1973 vette?
also the intake manifold has a code number - "GM CFM 1405705"
which seems to been used on cars between 1980 -1988 ??
cheers
dave
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Thread Starter
Racer
Joined: Jul 2007
Posts: 256
Likes: 0
From: Glasgow, Scotland
cheers
dave
Thread Starter
Racer
Joined: Jul 2007
Posts: 256
Likes: 0
From: Glasgow, Scotland
update - got a vac tester and timing light now!, attack that this weekend,
I have worked out the high idle speed was been caused by the throttle of the carb not shutting down completely, which is beening caused by the poor position of the back spring, so can someone tell me what the spring should be attached too?, pictures would be helpful, pics of my spring setup can be seen in one of my previous posts on this thread
cheers
dave
I have worked out the high idle speed was been caused by the throttle of the carb not shutting down completely, which is beening caused by the poor position of the back spring, so can someone tell me what the spring should be attached too?, pictures would be helpful, pics of my spring setup can be seen in one of my previous posts on this thread
cheers
dave
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
The spring runs from the lower portion of the throttle arm lever back to the throttle cable bracket. There is a small spring hole in both components.
Thread Starter
Racer
Joined: Jul 2007
Posts: 256
Likes: 0
From: Glasgow, Scotland
cheers
dave
Burning Brakes
Joined: Jun 2004
Posts: 872
Likes: 3
From: Cortlandt Manor New York
In order for it to be correct the strings that are tied to the choke need to be blue in color. The tan ones are definately a Bubba add on. I have seen them many times before. Definitetly looks like an eastern Misisissippi carb fix.
Thread Starter
Racer
Joined: Jul 2007
Posts: 256
Likes: 0
From: Glasgow, Scotland
lol, the car came from Misisissippi!, so why would someone puts wire strings around choke??
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Throttle linkage looks something like this.
Here is choke.
At bottom, the small rectangular plate with two black bolts is where the choke tube attaches.
Some of the plumbing, including the heat tube under the plate mentioned above (two are shown).
Here is choke.
At bottom, the small rectangular plate with two black bolts is where the choke tube attaches.
Some of the plumbing, including the heat tube under the plate mentioned above (two are shown).
Last edited by Paul L; Aug 24, 2007 at 08:40 AM.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
They have put wire ties around your choke linkage because you have the wrong carb for the appllication, making your choke inoperable and not capable of functioning, as noted earlier. The ties have been installed to lock the choke and disable it since it cannot be made to function with your combination of carb and manifold.
There shold not be any forward-running spring for throttle return - your car uses a dual spring running as noted in my earlier post.
There shold not be any forward-running spring for throttle return - your car uses a dual spring running as noted in my earlier post.