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Discussion Starter · #1 ·

Hey everyone. Wondered if anyone has a few troubleshooting points as to why my car idles like in the streamable video link. So far my thoughts are it could be a vaccum leak or potential fuel pressure issue. Would the timings being off also do this? This is with no action on the gas by the way.

One of the floats punctured a month ago, managed to take the whole thing apart and clean / rebuild (with a lot of swearing). When I got the car 6 months ago ran fine and idled nicely. A few months later it started idling fast at around 1200 and then the float punctured meaning carb kept flooding. After refitting still idles fast but also does this, I've fit a new gasket but also used some liquid gasket so should be tight.

Also picture of car since not posted it yet :) In the UK so don't see many

Cheers!
 

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1976,Firebird,Formula, 350 Engine,350 Trans.
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I will go out on limb and say the EGR valve is sticking open, i dont even know if yours has one.
 

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When you took the carb apart & repaired it, are you sure you put everything back together correctly? Did you adjust the idle mixture screw? And, did you completely disassemble carb and stick the parts in carb cleaner?

Is the choke assembly working correctly? Sometimes when people take apart a quad jet carb, they don't assemble the choke lever correctly.
 

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Liquid gasket and a carberator shouldn't go together in my opinion.
Lots goes into a carb rebuilt. Getting the different circurits clean and opened with new gaskets and rubber where needed and proper accelerator pump operation is only part of a rebuild.
 

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Discussion Starter · #6 · (Edited)
When you took the carb apart & repaired it, are you sure you put everything back together correctly? Did you adjust the idle mixture screw? And, did you completely disassemble carb and stick the parts in carb cleaner?

Is the choke assembly working correctly? Sometimes when people take apart a quad jet carb, they don't assemble the choke lever correctly.
I'm confident everything went back how it should, took me ages to get the springs right on the throttle linkage! Everything taken out, soaked in carb cleaner and all wiped down. All springs looked in good condition so all went back in as ended up with a cheap chinese rebuild kit so original bits better (apart from the float I needed to replace).

The idle mixture screw isn;t doing anything, even when all the way out it idles around 1200.

The choke is wired open, came like that and not sure yet if any point reversing it.
 

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Discussion Starter · #7 ·
Liquid gasket and a carberator shouldn't go together in my opinion.
Lots goes into a carb rebuilt. Getting the different circurits clean and opened with new gaskets and rubber where needed and proper accelerator pump operation is only part of a rebuild.
Agreed, unfortunately the kit I got was a knock off. The gaskets for inside the carb all fit fine but the one that site between the carb and engine wasn't, so made a whistling / reed sound at first when started, Small bead of gasket seemed to stop it but currently planning on ordering a proper edelbrock rebuild kit when I can get one shipped in case that's cauising the issue. Suppose one or two slightly off fitting gaskets inside could cause something like this?
 

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Stupid question, is the throttle stop screw turned in too far keeping the butterflies open a bit too much?
 

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To check for vac leak start motor and let run and spray carb cleaner around vac lines base of carb to see if rpm change. The throttle valve shaft can where out on the base plate. Can you move the shaft any with your hand ?
 
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