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Is this totally crazy or what?

T

themons

Member
I have been posting about my problems with replacing my quadrajets with Edelbrock 1409s. The current problem is not being able to get over 3000 rpms.

After trying both the electric choke and wire tie setups, I decided to try the engines without any type of choke setup.

Guess what?

The engine seems to run properly now or at least as well as when it had the quadrajets. The PO had also disconnected the quadrajet choke controls when he had owned it.

Comments?
 
I don't get it either; if the chokes were "tied open" why didn't it happen then? something else had to change.
 
The choke plates are still there. They're in the closed position since the electric choke coil is disconnected and they are not wired open.
 
So, you have "better" running engines with the chokes fully closed???

I'd suspect you have a major vacuum leak - wrong or damaged gasket(s) maybe, involving the new carb swap. That vacuum leak will also "disable" the secondaries as the air valve will Never open. time to get the vacuum gauge outif you wanna verify.
 
I forgot a bit of the "other" thread, but if you planted the 1409's on the stock iron manifolds, you need to use an adapter or get lucky on the wedge and gaskets. The q jet has bigger, much bigger secondary holes that the AFB style carb won't fill. It does sound like you have a vacuum leak, meaning a run lean condition, ergo, they run better with choke. BUt, no where near full power, and likely not efficiently either.
 
I have both the adapter plates and the wedges installed along with new gaskets. Everything fits together as it should. I haven't done a vacuum test, but I would be surprised if there were a major leak.

I think the air is coming through the secondary air valve.

That's why this is so crazy.

I am going to test it out on the water tomorrow with the flow scans.
 
..."I think the air is coming through the secondary air valve."

Not on an Edelbrock. They don't have one.

It sounds like you have a major vacuum leak. Try spraying carb cleaner about the bottom of the carb as it idles and see if the motor picks up rpms.

Note: Use lots of ventilation, and have the hatches open, as you do this.

Jeff
 
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