At my wits end with this QuadraJet

[Rktpwrd]

Anybody able to answer the question if the engine is able to run on the primary circuit rather than the idle circuit?

I can’t see any other explanation for why I have to rev it that high to get it to stay running.

 

[olds307 and 403]

I think that is exactly why it won't run until you get into the primary circuit. I think mine also would barely idle and my base timing needed cranked way up which contributed to pinging.

 

[Rktpwrd]

I think that is exactly why it won't run until you get into the primary circuit. I think mine also would barely idle and my base timing needed cranked way up which contributed to pinging.

Thanks for the insight. Maybe I’ll have to look into enlarging the idle orfice restrictions...???
I have the timing advanced for the best power, but there’s no signs of detonation. Don’t recall offhand what the final total timing number is now anymore, but it spins over without too much trouble and makes good power.

 

[TURNA]

I have no input besides

Everyday Performance just built me a Qjet and the price with a core was excellent!!!!

 

[lilbowtie]

I hate giving any advice on carb problems because there are so many variables. To answer your question you can be on the primary circuit, the throttle blades should show no more than .040 of the transfer slot in the closed position. Your idle screws should be 1 and a 1/2 turns out

 

[pontiacgp]

if it won't idle and it's running pig rich I would take the carburetor apart and start over making sure you are using the correct gaskets and make sure the float level is correct. If you changed the primary rods make sure you didn't mistakenly use a rods from a 74 and down version of the quadrajet.

 

[olds307 and 403]

As said the rods aren't interchangeable between Qjet series. I am betting the carb is ridiculously lean at idle for his motor. Donovan, what do you think the compression ratio is approximately? Cliff Ruggles shows the modifying the idle tubes and drilling out and the passages at the mixture screws as well in his book. Do you remember what jets an rods were in it? A sinking float messes can cause all sorts of issues but that was tested and set.

 

[Texas82GP]

Donovan,

How did the car run with this carb before the rebuild?

 

[HAFROD]

Is there a section in the book about mods for bigger than stock camshafts? Q-Jets do not like cams and need some tweaks

 

[HAFROD]