I replaced my Edlebrock carb last night with a Holley Street Avenger 570cfm and also installed a 1" spacer plate. Now I cannot seem to get the engine to run right, if at all. Right out of the box my warm idle was around 1500rpm, I adjusted it down but then have a hard time keeping it running. It also sounds like I have a miss at the tailpipes. I tried to adjust the timing but if I pull the vacuum advance off and plug it the car won't start.

Can someone give me an idea where I need to start?

 

Um, just how bad do you want to use a Holley?

Disconnecting the vacuum advance should do nothing at all at idle. Maybe the carb is defective.

 

About as bad as the $300+ I have in it.

 

Buy it new? It could be defective.

 

Sounds like a vac leak or a LEAN condition to me...

Are all of the hose ports blocked or used? Did the gasket seat right on the manifold/spacer/carb?

Did you check the float levels? The front bowl is the one that matters for idle, it will have a "window" or a screw to remove to check the level.

Adjusting the level is easy enough (check your literature that came with the carb), a little bit of adjustment on the nut goes a long way)

Adjust the front bowl before you even LOOK at the back bowl, the front is 10X easier to set. (because the front bowl uses fuel whenever the engine runs)

Sometimes these things will run fine out of the box, and sometimes they don't, this applies to ANY brand carb...

 

Vacuum leak

 

Not trying to be a smart ***, but I would consider putting the Edlebrock carb back on it, if it was running well before. What was the reason for the carb change?

 

The 1" spacer may explain your lean condition. Some folks have had to rejet up a size after installing them. And yet others have not. Something to consider though.

Good luck.

 

1500 at warm. When you lowered it the choke might be off and it's now disconnected. Open both mixture screws to one and a half turns. Disconnect the vacuum hose to distributor that you probably have at bottom of carb to passenger side above the mixture screws. Block all other vacuum connectors at carb. Especially the big one. Then try to get engine started with pedal half down and when it starts keep her running. I'd necessary with a bit of feathering the throttle. When warm adust the curb idle screw so that it runs at around 850 at park. The 570 street avenger is a brilliant carb for a 289 with intake and headers done. Loved it