Need help
Thread Starter
5th Gear
Joined: Apr 2022
Posts: 5
Likes: 1
Need help
So I bought my vette a month or so ago and it is already carb swapped but was done by a kid so it’s running rough . So far I’ve replaced all the plug wires and spark plugs and that helped some but I’m thinking my problems may be vacuum related. Does anyone know of the correct way to connect all the vacuum lines to carb? I’m not a mechanical genius by any means but I try to do all the work I can myself. Thanks in advance
Pro
Joined: Jan 2010
Posts: 611
Likes: 28
From: Olympia WA
A service manual would help you out a lot, I'd start there.
That being said there should be a large port for your vacuum booster, hook the booster to the large port. For all other vacuum lines I'd just make a simple manifold connected to the full vacuum port on the carb.
That being said there should be a large port for your vacuum booster, hook the booster to the large port. For all other vacuum lines I'd just make a simple manifold connected to the full vacuum port on the carb.
Pro
Joined: Feb 2009
Posts: 655
Likes: 164
From: Vancouver Washington
Not a lot of vacuum connections on an aftermarket carb. Distributor possibly. Brake booster should be a one hose affair then you need vacuum for the heater controls and cruise. I would think all of this vacuum would come off the intake it self.
My first question is what size is the carb?
Intake gasket leaks?
My first question is what size is the carb?
Intake gasket leaks?
Thread Starter
5th Gear
Joined: Apr 2022
Posts: 5
Likes: 1
Okay I’ll look around for a service manual and the carb is a edlebrock 650cfm I believe the performer carb mated to a Torker 2 intake and it looked like there was some residue at the rear of the intake I noticed when doing plug wires. I have a new intake gasket but haven’t installed yet.
Melting Slicks
Joined: Jul 2003
Posts: 3,482
Likes: 864
From: Saratoga Springs NY
2024 C4 of the Year Finalist - Modified
2022 C4 of the Year Finalist - Modified
Best thing to do here is to post some pictures of the setup you have. This was we can all see how its hooked up and help from there.
Racer
Joined: Jul 2012
Posts: 383
Likes: 86
From: Northeast Ohio
There is a vacuum port on the intake between the carb and the distributor. Usually there is a tee fitting there for some vacuum lines...something like this: https://www.summitracing.com/parts/sum-221133
Here's the manual for Edelbrock's 1906 carb...your 650 should be similar. If it looks much different you should be able to find the manual at Summit Racing or Edelbrock's site.
https://static.summitracing.com/glob...dl-1905_cv.pdf
Here's the manual for Edelbrock's 1906 carb...your 650 should be similar. If it looks much different you should be able to find the manual at Summit Racing or Edelbrock's site.
https://static.summitracing.com/glob...dl-1905_cv.pdf
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Thread Starter
5th Gear
Joined: Apr 2022
Posts: 5
Likes: 1
Alright here’s some pictures of the engine bay . Full backstory on the car supposedly kid had a Holley sniper kit on it previous to my purchase. He said he couldn’t get what he was wanting for the car with it installed so he removed the Holley system and threw on the edlebrock . He told me it would need tuned so I did a rebuild on the carb and cleaned the jets, replaced plugs and wires and that’s as much as I’ve done to it. The car stumbles on takeoff and cleans up about 2700-3000 rpm’s and has an inconsistent idle . The idle will clean up a little after it’s warm but stumble on takeoff is still there. Other mods to motor are a comp solid lift cam and hooker headers. Kid said cam was installed by previous owner and didn’t know the cam spec.
Melting Slicks
Joined: May 2005
Posts: 3,134
Likes: 11
From: At the St. Louis Playboy club.
That's hilarious **** right there.
The distributor is in 2 teeth off.
Firing order looks correct but wires running needlessly around.
Personally I'd rather have the Holly.
Temp sensor not wired.
I can't see where it's getting brake booster vacuum from but probably should be where the PVC is attached.
What's your financial plan?
I would do the cylinder leak down test, to get an idea of overall integrity.
Consider getting the correct intake, or a Fitech system.
A stall on takeoff usually means not enough accelerator pump.
You have a journey ahead.
The distributor is in 2 teeth off.
Firing order looks correct but wires running needlessly around.
Personally I'd rather have the Holly.
Temp sensor not wired.
I can't see where it's getting brake booster vacuum from but probably should be where the PVC is attached.
What's your financial plan?
I would do the cylinder leak down test, to get an idea of overall integrity.
Consider getting the correct intake, or a Fitech system.
A stall on takeoff usually means not enough accelerator pump.
You have a journey ahead.
Thread Starter
5th Gear
Joined: Apr 2022
Posts: 5
Likes: 1
Eventually I was wanting to return it to a Holley sniper system again and end goal for the car is a fun daily once it’s right but we’re far from that for the moment. I bought the car more so to learn how to work on cars than anything else and thought sbc would be an easier platform for a newbie . Thanks for the assessment of it being a shitshow…. I already knew that though. I’m gonna try to work on it more this weekend and I’ll try moving the distributor two teeth and buy some vent line tubing so I can try to get it back correct. I want to get the engine running right before I tackle the a/c issue
Melting Slicks
Joined: May 2005
Posts: 3,134
Likes: 11
From: At the St. Louis Playboy club.
Well the **** show is courtesy of the prior owner, nothing on you.
Run the compression check.
They are known for burnt valves.
Hook up a timing light, should be 30 above 2000 rpm.
Remove valve covers, check rocker clearance. Check timing chain by moving the harmonic balancer back & forth while watching for cam movement.
I'm glad to help, & hope you have fun.
Run the compression check.
They are known for burnt valves.
Hook up a timing light, should be 30 above 2000 rpm.
Remove valve covers, check rocker clearance. Check timing chain by moving the harmonic balancer back & forth while watching for cam movement.
I'm glad to help, & hope you have fun.
Melting Slicks
Joined: May 2005
Posts: 3,134
Likes: 11
From: At the St. Louis Playboy club.
Just remembered they put a cam in it, so nevermind about the timing chain test.
How many miles?
If the heads are untouched, I'd bet on burnt valves causing idle issues.
The distributor just looks crappy, makes me want to check the advance springs, cheap fix.
How many miles?
If the heads are untouched, I'd bet on burnt valves causing idle issues.
The distributor just looks crappy, makes me want to check the advance springs, cheap fix.
Melting Slicks
Joined: Jul 2003
Posts: 3,482
Likes: 864
From: Saratoga Springs NY
2024 C4 of the Year Finalist - Modified
2022 C4 of the Year Finalist - Modified
I agree with above, but also id hook up a vacuum gauge to the engine and see what you have. If you have burnt valves,etc, it will show on the gauge. Inconsistent idle could be vacuum leak, and judging by the hoses it defiantly possible.
Check timing (after you look at the weights and springs as mentioned above).
Did you pull spark plugs to compare to one another?
What are you running for a fuel pump? Also what transmission do you have?
Check timing (after you look at the weights and springs as mentioned above).
Did you pull spark plugs to compare to one another?
What are you running for a fuel pump? Also what transmission do you have?