car won't idle & getting best vacuum with mixtures almost closed

hi all

tittle says it all. just another thing tacked on for a problem. would increasing primary jet size cause the car to need less of the idle mixtures open? or do i have a different problem? I'm at a 70 primary jet to make up for the flow rating being so much for my motor. tried it with 2 different power valves and it didn't help at all. haven't tried to see if it will idle at best vacuum with the mixtures almost all the way closed but thats next.

any suggestions? also i was offered a 600 DP as a trade for my carb, my question is, do you suggest i go through with the trade? i know DPs aren't as nice to you on the street as vacuum secondary, but I'm not worried about that. just want a good performance car.

specs: roller 302 with stock e7s, edelbrock rollin thunder cam, Holley 670 street avenger, T5 trans, weiland dual plane intake

 

I've never seen jet size make a difference to idle, idle vs cruse are different circuits...

Likely you have a gasket issue or stirred up some sediment when you had the carb open...

 

Okay I ll check my gaskets and spray some cleaner in the circuits... Hopefully that does something

 

sounds like a vac. leak...

 

A vacuum leak?? I never tried that yet...

 

I agree on possible vaccum leak.

 

I never checked that... That's deffinitly something to check.

 

I had a vac. leak once that was so bad I could smother the throat of the carb with a rag and the car kept running...

 

wow thats crazy.... okay ill look into that today

 

Well I doubt it's a vacuum leak, at least not external to carb... With the idle mixtures almost closed it should be very lean and not want to idle, extra air from vac leak would lean it even more...

Problem is it's apparently too rich, idle bleeds must be closed to compensate...

 

where could it be too rich from? is it possible that this problem could arise from having the secondaries open too much at idle? or having too much transfer slot exposed? it can't be the power valve because i tried that and it made no difference. I'm just gonna "reset"the carb and see what happens (close the secondary idle screw, put my 6.5 PV in, etc) if not I'm gonna check for vacuum leaks.

 

I just did all the stuff I said in the post above... It didn't help. I did notice some slack in the secondaries though. There's not supposed to be any slack when the primaries are closed right? Could the secondaries opening at idle cause the problems I'm having? It's enough play to show the secondary slots

 

Thats very common on holleys. Used to make me a lot of money those secondary adjustments. yes it will cause your issue.

 

Really this is common? How do you fix it? Is it a matter of adjusting the rod thing that allows the secondaries to open when the primaries do?

 

I'm betting the secondary throttle blade is slightly open, which as was previously mentioned will totally cause that problem. Does the exhaust smell rich at idle? Does it make your eyes burn?