Just did 2 to 4 bbl swap car starts wont stay running please help

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67cudaResto89

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So i i took off my old 2 bbl and cast intake and put on a edelbrock performer intake edelbrock performer 600carb with elect choke conversion and the lokar throttle cable and kickdown cable setup. Car will start and run if you press on the gas but once u let go it dies. Seems like a vac leak but everything is plugged or has a hose on it any idea or anyone run into this before this was my first swap
Shane
 
Thats is a vacuum leak,check around the base of the carb,and where the intake mates to the head. Re-check the torque on all of the bolts.
 
Maybe you just need to start with adjusting the idle. There should be a screw that you can turn in that will hold the throttle open just a touch. Once you get it to idle you can start on tuning it.
 
On the front of that carburetor you will have three vacuum ports. The large center port is generally used for the PCV. The small one to the left that is slightly higher goes to your timing/distributer. The small one to the right is either blocked off or goes to some automatic transmissions. Make sure all lines and plugs are sealed properly. Make sure you have the correct carburetor adapter plate for the performer 600 OR YOU WILL HAVE AIR LEAKS. MMG
 
Sry. They said center port on the carb goes to pcv i dont have one other owner put edelbrock covers on it with 2 breathers (no pcv) so instead of runnin the vac line to the non existent pcv i ran it to a main manifold vac. A little better sorry gettin frustrated workin on the car and typin on an iphone sucks.
 
since you changed the intake and the carb and added a lokar throttle cable, I would go with what magnumdart suggested. Make sure the cable and the idle screw is setup correctly. This will most likely be the reason why it won't stay running after you let off the throttle.

If that is all taken care off, maybe check for vacuum leaks around the intake and the base of the carb and fittings, you can do this by spraying some water on the area while the engine is running. Any change in RPM suggests a leak.
 
No worries,so you ran a line from the PCV port on the carb to a manifold vacuum source? If so you need to remove this line and just cap the PCV port on the carb and the manifold vacuum source.
 
turn up the idle enough to just keep it running. go under the hood with a bottle of water, and spray over all areas you worked on, once you find the leak with the spray, you will hear the engine rev up, as the water kinda blocks the leak for a second. i say the leak is at either the front or rear of the intake, where those garbage cork gaskets go
 
I sprayed the carb down by the base nd it started to surge and fluctuate but there is no reason why it should be leaking. So the center vaccum port isnt needed. Ill try that And get back to u tomoro. Thats for ur help
 
There may not be a "reason" why its leaking,but it is leaking. The adapter could be warped the gasket bad etc...get some black RTV and put a light coat on the mounting surfaces,and make sure to torque everything down snug and that should solve your problems.
 
take the spacer off. plug your pcv. plug the intake vacuum port. make sure all vacuum ports are plugged on the carb. make sure the idle screw is against and moving the throttle. make sure your mixture screws are a 1 1/2 out or so. make sure you have fuel.make sure the choke is open ,fire it up, keep it running and then start tuning and the add your spacers and what nots.
 
When u say make sure the screws r 1 1/2 out wat do u mean by that i understand they r the mixture screws but do u mean turns or something else?
 
67cudaResto89 said:
When u say make sure the screws r 1 1/2 out wat do u mean by that i understand they r the mixture screws but do u mean turns or something else?
Click to expand...

Yes, one and one half turns from lightly bottomed is a good staring point. Fine tune from there.
 
The rear port is blocked off. The idle screw wasnt adjusted properly i screwed it down now i got it running but i got some other issues. When i come to a stop the idle gets wacky kinda feels like its gona die ali i step kn the gas its alright. After i got done my test drive the headers were glowing red. Im assuming its running very rich?
 
glowing headers usually mean it is running too lean not rich (or the timing is too retarded) What is your timing set at idle (no vacuum advance hooked up) and what is the setup of your carb (jets + rods)?
 
Îts set at tdc 0 degrees. Its an out of the box edelbrock performer 600- not quite sure on rods nd jets. I have a mallory elec dizzy installed
 
Yup both side r gasketed and the pcv is plugged after j turned the idle screw up j sprayed around the carb and found no leaks and around the intake found no leaks. So im not quite sure as to why its running like it had a leak. Its got a mild cam but even with that the idle shouldnt drop as low as it does
 
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