Hey all, I recently found out that my edelbrock 600 cfm carb was not calibrated correctly to run my motor. A friend of mine had a spare Holley 650 DP lying around that he gave to me. It needed to be rebuilt so i spent the past 2 1/2 days cleaning it up and getting it ready to drop onto my car. So last night i ran into a few problems and i corrected what i could.

So the holley was hitting the vacuum fitting that was coming out of the intake manifold. i went with a more shallow fitting and it helped some but i still needed a 1/4 inch of clearance. I ran out to the store and picked up a Carb Spacer Plate kit with longer studs to solve the clearance problem.

The next problem i ran into was solving the vacuum lines locations. I have an electric choke on the holley and i know i need vacuum from the motor to work properly. Now there is a 3/8" PCV port on the back of the carb, and 2 other Vacuum Ports on the Carb, One in the front that im not sure what is for and the one on the Passenger side of the carb that i believe runs the vacuum advanced for the distributor. Can anyone send me a diagram on what vacuum lines i need to utilize in order for my car to run correctly?

Right now i have a basic idea that i believe should work but i would like a second opinion. I have a Vacuum Port that is right behind my carb that i am running to the brake booster and have nothing else branching off of it. now the PCV Port on the back of the carb i want running to the PCV Valve on my Valve cover.

Now here is where the problem occurs. i only have one direct vacuum port on my manifold and do not really want to tap the manifold to create another. I need Vacuum to Run the Electronic Choke, and Vacuum to run to the Heater Controls and Vacuum Ball. The Vacuum ball and Heater Controls have the anti backup valve on it and i just plug into the front of it and it creates vacuum.

I need someone to instruct me on which vacuum ports i can use on the carb, and where i can possibly Tee-Off to send vacuum to either the heater controls or the vacuum for the electronic choke.

Now for my last problem, The Vapor Canister. So before i swapped out my edelbrock 600 cfm carb, i had a line from the Vapor canister that ran into the front of the edelbrock carb. Now since the Holley doesn't have a port to support that line, i was wondering what i could do with it. I keep getting mixed reviews on it. Some people say to remove it completely, others say to keep it and run the line. I want to know what would be the best solution for the canister. I have a spare gas cap that is vented if i cap it off but i rather just run it to the carb how it was originally intended to do. does anyone have any idea what to do with this line?

Please send me some suggestions, im confused on the whole matter and want to get it corrected ASAP...

Thanks

 

Not sure why you need vacuum to run an electronic choke - electric choke takes electricity, not vacuum. You need vacuum for the heater controls, and that's about it. You need a check valve in place to store the vacuum in the vacuum ball under the driver side headlight, and the check valve. This vacuum can come off a T from the brake line vacuum.

Vapor canister can be removed altogether - no need for it at all. Just route a rubber line from the third fuel line that goes to vapor canister out and under car so there's never any chance of fuel vapors or fuel spitting out of that line onto hot headers etc.

 

I know and understand that it is an electronic choke and you need electric to run it, but there is a vacuum line that runs out of the side of it.

for the Vapor Canister i would want a better solution then just dumping the fuel line out and under the car

 

buddy i dont think they work i got a 91 with vapor canister and i open up the lid and all sorts of vapor shoot out. Scared the crap outta me...

 

My vapor can has been in the city dump for 6+ years now, with no issues at all. There's not any fuel running out of the line - just vapors from the tank. Once in the last 6 years, I had alot of presure build up in the tank, and 4 drops of fuel came out of the vapor can line - but that was the only instance. Running an extra chunk of rubber fuel line out and under the car is just added safety precaution - it's not like it's constantly leaking.

 

I understand that, But there is nothing wrong with my Vapor Canister. It is still connected properly and seems to be working fine. If i cap off those lines would i need to put on a vented gas cap??

 

What model Holley is this - should be a List number stamped on the choke horn. Different models have different ports, might help you to search online to determine what you have.

So you've got 3 vac ports - two big ones on the throttle body front & rear, and a timed vac port coming off the side of the metering block.

Usually the brake booster will plug directly into the manifold, or the rear carb port. PCV valve will usually go the the front port. Timed vac port is for a vac advance distributor only.

If those are all you've got, you'll have to tap either the front or rear port for the HVAC and the vac canister, the front being the more usual. Or dump the vac canister output into the air cleaner - if the evap system currently works, try keep it working.

Then there's the other approach - find why your Edel carb was not 'calibrated correctly', and fix it. At least you know it connected up ok. Also remember the DP will give you much worse fuel economy.

 

I pretty much got it all solved. i did about 4 hours of research and about 30 mins on the phone with Tech support from holley and this is what i got.

out of the 4 vacuum lines on the holley carb, the pcv goes directly to the pcv valve

the vac line off the metering block goes to the distributor

the other two vacuum lines that are off the electronic choke and the front of the carb are T'd together and are in line with the heater controls and vacuum line

and my vapor canister now runs to my air cleaner


all my problems need to be solved and that Edelbrock carb is for sale